diff --git a/doc/src/sgml/ref/create_conversion.sgml b/doc/src/sgml/ref/create_conversion.sgml
index e7700fecfc5..75d7b009455 100644
--- a/doc/src/sgml/ref/create_conversion.sgml
+++ b/doc/src/sgml/ref/create_conversion.sgml
@@ -117,9 +117,15 @@ conv_proc(
     integer,  -- destination encoding ID
     cstring,  -- source string (null terminated C string)
     internal, -- destination (fill with a null terminated C string)
-    integer   -- source string length
-) RETURNS void;
-</programlisting></para>
+    integer,  -- source string length
+    boolean   -- if true, don't throw an error if conversion fails
+) RETURNS integer;
+</programlisting>
+       The return value is the number of source bytes that were successfully
+       converted. If the last argument is false, the function must throw an
+       error on invalid input, and the return value is always equal to the
+       source string length.
+      </para>
      </listitem>
     </varlistentry>
    </variablelist>
diff --git a/src/backend/commands/conversioncmds.c b/src/backend/commands/conversioncmds.c
index f7ff321de71..5fed97a2f99 100644
--- a/src/backend/commands/conversioncmds.c
+++ b/src/backend/commands/conversioncmds.c
@@ -45,8 +45,9 @@ CreateConversionCommand(CreateConversionStmt *stmt)
 	const char *from_encoding_name = stmt->for_encoding_name;
 	const char *to_encoding_name = stmt->to_encoding_name;
 	List	   *func_name = stmt->func_name;
-	static const Oid funcargs[] = {INT4OID, INT4OID, CSTRINGOID, INTERNALOID, INT4OID};
+	static const Oid funcargs[] = {INT4OID, INT4OID, CSTRINGOID, INTERNALOID, INT4OID, BOOLOID};
 	char		result[1];
+	Datum		funcresult;
 
 	/* Convert list of names to a name and namespace */
 	namespaceId = QualifiedNameGetCreationNamespace(stmt->conversion_name,
@@ -92,12 +93,12 @@ CreateConversionCommand(CreateConversionStmt *stmt)
 	funcoid = LookupFuncName(func_name, sizeof(funcargs) / sizeof(Oid),
 							 funcargs, false);
 
-	/* Check it returns VOID, else it's probably the wrong function */
-	if (get_func_rettype(funcoid) != VOIDOID)
+	/* Check it returns int4, else it's probably the wrong function */
+	if (get_func_rettype(funcoid) != INT4OID)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
 				 errmsg("encoding conversion function %s must return type %s",
-						NameListToString(func_name), "void")));
+						NameListToString(func_name), "integer")));
 
 	/* Check we have EXECUTE rights for the function */
 	aclresult = pg_proc_aclcheck(funcoid, GetUserId(), ACL_EXECUTE);
@@ -111,12 +112,23 @@ CreateConversionCommand(CreateConversionStmt *stmt)
 	 * string; the conversion function should throw an error if it can't
 	 * perform the requested conversion.
 	 */
-	OidFunctionCall5(funcoid,
-					 Int32GetDatum(from_encoding),
-					 Int32GetDatum(to_encoding),
-					 CStringGetDatum(""),
-					 CStringGetDatum(result),
-					 Int32GetDatum(0));
+	funcresult = OidFunctionCall6(funcoid,
+								  Int32GetDatum(from_encoding),
+								  Int32GetDatum(to_encoding),
+								  CStringGetDatum(""),
+								  CStringGetDatum(result),
+								  Int32GetDatum(0),
+								  BoolGetDatum(false));
+
+	/*
+	 * The function should return 0 for empty input. Might as well check that,
+	 * too.
+	 */
+	if (DatumGetInt32(funcresult) != 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+				 errmsg("encoding conversion function %s returned incorrect result for empty input",
+						NameListToString(func_name))));
 
 	/*
 	 * All seem ok, go ahead (possible failure would be a duplicate conversion
diff --git a/src/backend/utils/error/elog.c b/src/backend/utils/error/elog.c
index 9e4ea1b345a..423df2f3006 100644
--- a/src/backend/utils/error/elog.c
+++ b/src/backend/utils/error/elog.c
@@ -2271,6 +2271,8 @@ write_console(const char *line, int len)
 	 * Conversion on non-win32 platforms is not implemented yet. It requires
 	 * non-throw version of pg_do_encoding_conversion(), that converts
 	 * unconvertable characters to '?' without errors.
+	 *
+	 * XXX: We have a no-throw version now. It doesn't convert to '?' though.
 	 */
 #endif
 
diff --git a/src/backend/utils/mb/conv.c b/src/backend/utils/mb/conv.c
index a07b54bd3b8..33e9c9a9e3c 100644
--- a/src/backend/utils/mb/conv.c
+++ b/src/backend/utils/mb/conv.c
@@ -25,15 +25,20 @@
  * tab holds conversion entries for the source charset
  * starting from 128 (0x80). each entry in the table holds the corresponding
  * code point for the target charset, or 0 if there is no equivalent code.
+ *
+ * Returns the number of input bytes consumed.  If noError is true, this can
+ * be less than 'len'.
  */
-void
+int
 local2local(const unsigned char *l,
 			unsigned char *p,
 			int len,
 			int src_encoding,
 			int dest_encoding,
-			const unsigned char *tab)
+			const unsigned char *tab,
+			bool noError)
 {
+	const unsigned char *start = l;
 	unsigned char c1,
 				c2;
 
@@ -41,7 +46,11 @@ local2local(const unsigned char *l,
 	{
 		c1 = *l;
 		if (c1 == 0)
+		{
+			if (noError)
+				break;
 			report_invalid_encoding(src_encoding, (const char *) l, len);
+		}
 		if (!IS_HIGHBIT_SET(c1))
 			*p++ = c1;
 		else
@@ -50,13 +59,19 @@ local2local(const unsigned char *l,
 			if (c2)
 				*p++ = c2;
 			else
+			{
+				if (noError)
+					break;
 				report_untranslatable_char(src_encoding, dest_encoding,
 										   (const char *) l, len);
+			}
 		}
 		l++;
 		len--;
 	}
 	*p = '\0';
+
+	return l - start;
 }
 
 /*
@@ -66,18 +81,26 @@ local2local(const unsigned char *l,
  * p is the output area (must be large enough!)
  * lc is the mule character set id for the local encoding
  * encoding is the PG identifier for the local encoding
+ *
+ * Returns the number of input bytes consumed.  If noError is true, this can
+ * be less than 'len'.
  */
-void
+int
 latin2mic(const unsigned char *l, unsigned char *p, int len,
-		  int lc, int encoding)
+		  int lc, int encoding, bool noError)
 {
+	const unsigned char *start = l;
 	int			c1;
 
 	while (len > 0)
 	{
 		c1 = *l;
 		if (c1 == 0)
+		{
+			if (noError)
+				break;
 			report_invalid_encoding(encoding, (const char *) l, len);
+		}
 		if (IS_HIGHBIT_SET(c1))
 			*p++ = lc;
 		*p++ = c1;
@@ -85,6 +108,8 @@ latin2mic(const unsigned char *l, unsigned char *p, int len,
 		len--;
 	}
 	*p = '\0';
+
+	return l - start;
 }
 
 /*
@@ -94,18 +119,26 @@ latin2mic(const unsigned char *l, unsigned char *p, int len,
  * p is the output area (must be large enough!)
  * lc is the mule character set id for the local encoding
  * encoding is the PG identifier for the local encoding
+ *
+ * Returns the number of input bytes consumed.  If noError is true, this can
+ * be less than 'len'.
  */
-void
+int
 mic2latin(const unsigned char *mic, unsigned char *p, int len,
-		  int lc, int encoding)
+		  int lc, int encoding, bool noError)
 {
+	const unsigned char *start = mic;
 	int			c1;
 
 	while (len > 0)
 	{
 		c1 = *mic;
 		if (c1 == 0)
+		{
+			if (noError)
+				break;
 			report_invalid_encoding(PG_MULE_INTERNAL, (const char *) mic, len);
+		}
 		if (!IS_HIGHBIT_SET(c1))
 		{
 			/* easy for ASCII */
@@ -118,17 +151,27 @@ mic2latin(const unsigned char *mic, unsigned char *p, int len,
 			int			l = pg_mule_mblen(mic);
 
 			if (len < l)
+			{
+				if (noError)
+					break;
 				report_invalid_encoding(PG_MULE_INTERNAL, (const char *) mic,
 										len);
+			}
 			if (l != 2 || c1 != lc || !IS_HIGHBIT_SET(mic[1]))
+			{
+				if (noError)
+					break;
 				report_untranslatable_char(PG_MULE_INTERNAL, encoding,
 										   (const char *) mic, len);
+			}
 			*p++ = mic[1];
 			mic += 2;
 			len -= 2;
 		}
 	}
 	*p = '\0';
+
+	return mic - start;
 }
 
 
@@ -143,15 +186,20 @@ mic2latin(const unsigned char *mic, unsigned char *p, int len,
  * tab holds conversion entries for the local charset
  * starting from 128 (0x80). each entry in the table holds the corresponding
  * code point for the mule encoding, or 0 if there is no equivalent code.
+ *
+ * Returns the number of input bytes consumed.  If noError is true, this can
+ * be less than 'len'.
  */
-void
+int
 latin2mic_with_table(const unsigned char *l,
 					 unsigned char *p,
 					 int len,
 					 int lc,
 					 int encoding,
-					 const unsigned char *tab)
+					 const unsigned char *tab,
+					 bool noError)
 {
+	const unsigned char *start = l;
 	unsigned char c1,
 				c2;
 
@@ -159,7 +207,11 @@ latin2mic_with_table(const unsigned char *l,
 	{
 		c1 = *l;
 		if (c1 == 0)
+		{
+			if (noError)
+				break;
 			report_invalid_encoding(encoding, (const char *) l, len);
+		}
 		if (!IS_HIGHBIT_SET(c1))
 			*p++ = c1;
 		else
@@ -171,13 +223,19 @@ latin2mic_with_table(const unsigned char *l,
 				*p++ = c2;
 			}
 			else
+			{
+				if (noError)
+					break;
 				report_untranslatable_char(encoding, PG_MULE_INTERNAL,
 										   (const char *) l, len);
+			}
 		}
 		l++;
 		len--;
 	}
 	*p = '\0';
+
+	return l - start;
 }
 
 /*
@@ -191,15 +249,20 @@ latin2mic_with_table(const unsigned char *l,
  * tab holds conversion entries for the mule internal code's second byte,
  * starting from 128 (0x80). each entry in the table holds the corresponding
  * code point for the local charset, or 0 if there is no equivalent code.
+ *
+ * Returns the number of input bytes consumed.  If noError is true, this can
+ * be less than 'len'.
  */
-void
+int
 mic2latin_with_table(const unsigned char *mic,
 					 unsigned char *p,
 					 int len,
 					 int lc,
 					 int encoding,
-					 const unsigned char *tab)
+					 const unsigned char *tab,
+					 bool noError)
 {
+	const unsigned char *start = mic;
 	unsigned char c1,
 				c2;
 
@@ -207,7 +270,11 @@ mic2latin_with_table(const unsigned char *mic,
 	{
 		c1 = *mic;
 		if (c1 == 0)
+		{
+			if (noError)
+				break;
 			report_invalid_encoding(PG_MULE_INTERNAL, (const char *) mic, len);
+		}
 		if (!IS_HIGHBIT_SET(c1))
 		{
 			/* easy for ASCII */
@@ -220,11 +287,17 @@ mic2latin_with_table(const unsigned char *mic,
 			int			l = pg_mule_mblen(mic);
 
 			if (len < l)
+			{
+				if (noError)
+					break;
 				report_invalid_encoding(PG_MULE_INTERNAL, (const char *) mic,
 										len);
+			}
 			if (l != 2 || c1 != lc || !IS_HIGHBIT_SET(mic[1]) ||
 				(c2 = tab[mic[1] - HIGHBIT]) == 0)
 			{
+				if (noError)
+					break;
 				report_untranslatable_char(PG_MULE_INTERNAL, encoding,
 										   (const char *) mic, len);
 				break;			/* keep compiler quiet */
@@ -235,6 +308,8 @@ mic2latin_with_table(const unsigned char *mic,
 		}
 	}
 	*p = '\0';
+
+	return mic - start;
 }
 
 /*
@@ -424,18 +499,22 @@ pg_mb_radix_conv(const pg_mb_radix_tree *rt,
  * is applied.  An error is raised if no match is found.
  *
  * See pg_wchar.h for more details about the data structures used here.
+ *
+ * Returns the number of input bytes consumed.  If noError is true, this can
+ * be less than 'len'.
  */
-void
+int
 UtfToLocal(const unsigned char *utf, int len,
 		   unsigned char *iso,
 		   const pg_mb_radix_tree *map,
 		   const pg_utf_to_local_combined *cmap, int cmapsize,
 		   utf_local_conversion_func conv_func,
-		   int encoding)
+		   int encoding, bool noError)
 {
 	uint32		iutf;
 	int			l;
 	const pg_utf_to_local_combined *cp;
+	const unsigned char *start = utf;
 
 	if (!PG_VALID_ENCODING(encoding))
 		ereport(ERROR,
@@ -505,10 +584,19 @@ UtfToLocal(const unsigned char *utf, int len,
 
 			l = pg_utf_mblen(utf);
 			if (len < l)
+			{
+				/* need more data to decide if this is a combined char */
+				utf -= l_save;
 				break;
+			}
 
 			if (!pg_utf8_islegal(utf, l))
+			{
+				if (!noError)
+					report_invalid_encoding(PG_UTF8, (const char *) utf, len);
+				utf -= l_save;
 				break;
+			}
 
 			/* We assume ASCII character cannot be in combined map */
 			if (l > 1)
@@ -584,15 +672,20 @@ UtfToLocal(const unsigned char *utf, int len,
 		}
 
 		/* failed to translate this character */
+		utf -= l;
+		if (noError)
+			break;
 		report_untranslatable_char(PG_UTF8, encoding,
-								   (const char *) (utf - l), len);
+								   (const char *) utf, len);
 	}
 
 	/* if we broke out of loop early, must be invalid input */
-	if (len > 0)
+	if (len > 0 && !noError)
 		report_invalid_encoding(PG_UTF8, (const char *) utf, len);
 
 	*iso = '\0';
+
+	return utf - start;
 }
 
 /*
@@ -616,18 +709,23 @@ UtfToLocal(const unsigned char *utf, int len,
  * (if provided) is applied.  An error is raised if no match is found.
  *
  * See pg_wchar.h for more details about the data structures used here.
+ *
+ * Returns the number of input bytes consumed.  If noError is true, this can
+ * be less than 'len'.
  */
-void
+int
 LocalToUtf(const unsigned char *iso, int len,
 		   unsigned char *utf,
 		   const pg_mb_radix_tree *map,
 		   const pg_local_to_utf_combined *cmap, int cmapsize,
 		   utf_local_conversion_func conv_func,
-		   int encoding)
+		   int encoding,
+		   bool noError)
 {
 	uint32		iiso;
 	int			l;
 	const pg_local_to_utf_combined *cp;
+	const unsigned char *start = iso;
 
 	if (!PG_VALID_ENCODING(encoding))
 		ereport(ERROR,
@@ -723,13 +821,18 @@ LocalToUtf(const unsigned char *iso, int len,
 		}
 
 		/* failed to translate this character */
+		iso -= l;
+		if (noError)
+			break;
 		report_untranslatable_char(encoding, PG_UTF8,
-								   (const char *) (iso - l), len);
+								   (const char *) iso, len);
 	}
 
 	/* if we broke out of loop early, must be invalid input */
-	if (len > 0)
+	if (len > 0 && !noError)
 		report_invalid_encoding(encoding, (const char *) iso, len);
 
 	*utf = '\0';
+
+	return iso - start;
 }
diff --git a/src/backend/utils/mb/conversion_procs/cyrillic_and_mic/cyrillic_and_mic.c b/src/backend/utils/mb/conversion_procs/cyrillic_and_mic/cyrillic_and_mic.c
index 4c5b02654de..368c2deb5e4 100644
--- a/src/backend/utils/mb/conversion_procs/cyrillic_and_mic/cyrillic_and_mic.c
+++ b/src/backend/utils/mb/conversion_procs/cyrillic_and_mic/cyrillic_and_mic.c
@@ -44,8 +44,11 @@ PG_FUNCTION_INFO_V1(win866_to_iso);
  *		INTEGER,	-- destination encoding id
  *		CSTRING,	-- source string (null terminated C string)
  *		CSTRING,	-- destination string (null terminated C string)
- *		INTEGER		-- source string length
- * ) returns VOID;
+ *		INTEGER,	-- source string length
+ *		BOOL		-- if true, don't throw an error if conversion fails
+ * ) returns INTEGER;
+ *
+ * Returns the number of bytes successfully converted.
  * ----------
  */
 
@@ -306,12 +309,14 @@ koi8r_to_mic(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_KOI8R, PG_MULE_INTERNAL);
 
-	latin2mic(src, dest, len, LC_KOI8_R, PG_KOI8R);
+	converted = latin2mic(src, dest, len, LC_KOI8_R, PG_KOI8R, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -320,12 +325,14 @@ mic_to_koi8r(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_MULE_INTERNAL, PG_KOI8R);
 
-	mic2latin(src, dest, len, LC_KOI8_R, PG_KOI8R);
+	converted = mic2latin(src, dest, len, LC_KOI8_R, PG_KOI8R, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -334,12 +341,14 @@ iso_to_mic(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_ISO_8859_5, PG_MULE_INTERNAL);
 
-	latin2mic_with_table(src, dest, len, LC_KOI8_R, PG_ISO_8859_5, iso2koi);
+	converted = latin2mic_with_table(src, dest, len, LC_KOI8_R, PG_ISO_8859_5, iso2koi, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -348,12 +357,14 @@ mic_to_iso(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_MULE_INTERNAL, PG_ISO_8859_5);
 
-	mic2latin_with_table(src, dest, len, LC_KOI8_R, PG_ISO_8859_5, koi2iso);
+	converted = mic2latin_with_table(src, dest, len, LC_KOI8_R, PG_ISO_8859_5, koi2iso, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -362,12 +373,14 @@ win1251_to_mic(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_WIN1251, PG_MULE_INTERNAL);
 
-	latin2mic_with_table(src, dest, len, LC_KOI8_R, PG_WIN1251, win12512koi);
+	converted = latin2mic_with_table(src, dest, len, LC_KOI8_R, PG_WIN1251, win12512koi, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -376,12 +389,14 @@ mic_to_win1251(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_MULE_INTERNAL, PG_WIN1251);
 
-	mic2latin_with_table(src, dest, len, LC_KOI8_R, PG_WIN1251, koi2win1251);
+	converted = mic2latin_with_table(src, dest, len, LC_KOI8_R, PG_WIN1251, koi2win1251, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -390,12 +405,14 @@ win866_to_mic(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_WIN866, PG_MULE_INTERNAL);
 
-	latin2mic_with_table(src, dest, len, LC_KOI8_R, PG_WIN866, win8662koi);
+	converted = latin2mic_with_table(src, dest, len, LC_KOI8_R, PG_WIN866, win8662koi, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -404,12 +421,14 @@ mic_to_win866(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_MULE_INTERNAL, PG_WIN866);
 
-	mic2latin_with_table(src, dest, len, LC_KOI8_R, PG_WIN866, koi2win866);
+	converted = mic2latin_with_table(src, dest, len, LC_KOI8_R, PG_WIN866, koi2win866, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -418,12 +437,14 @@ koi8r_to_win1251(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_KOI8R, PG_WIN1251);
 
-	local2local(src, dest, len, PG_KOI8R, PG_WIN1251, koi2win1251);
+	converted = local2local(src, dest, len, PG_KOI8R, PG_WIN1251, koi2win1251, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -432,12 +453,14 @@ win1251_to_koi8r(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_WIN1251, PG_KOI8R);
 
-	local2local(src, dest, len, PG_WIN1251, PG_KOI8R, win12512koi);
+	converted = local2local(src, dest, len, PG_WIN1251, PG_KOI8R, win12512koi, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -446,12 +469,14 @@ koi8r_to_win866(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_KOI8R, PG_WIN866);
 
-	local2local(src, dest, len, PG_KOI8R, PG_WIN866, koi2win866);
+	converted = local2local(src, dest, len, PG_KOI8R, PG_WIN866, koi2win866, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -460,12 +485,14 @@ win866_to_koi8r(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_WIN866, PG_KOI8R);
 
-	local2local(src, dest, len, PG_WIN866, PG_KOI8R, win8662koi);
+	converted = local2local(src, dest, len, PG_WIN866, PG_KOI8R, win8662koi, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -474,12 +501,14 @@ win866_to_win1251(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_WIN866, PG_WIN1251);
 
-	local2local(src, dest, len, PG_WIN866, PG_WIN1251, win8662win1251);
+	converted = local2local(src, dest, len, PG_WIN866, PG_WIN1251, win8662win1251, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -488,12 +517,14 @@ win1251_to_win866(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_WIN1251, PG_WIN866);
 
-	local2local(src, dest, len, PG_WIN1251, PG_WIN866, win12512win866);
+	converted = local2local(src, dest, len, PG_WIN1251, PG_WIN866, win12512win866, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -502,12 +533,14 @@ iso_to_koi8r(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_ISO_8859_5, PG_KOI8R);
 
-	local2local(src, dest, len, PG_ISO_8859_5, PG_KOI8R, iso2koi);
+	converted = local2local(src, dest, len, PG_ISO_8859_5, PG_KOI8R, iso2koi, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -516,12 +549,14 @@ koi8r_to_iso(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_KOI8R, PG_ISO_8859_5);
 
-	local2local(src, dest, len, PG_KOI8R, PG_ISO_8859_5, koi2iso);
+	converted = local2local(src, dest, len, PG_KOI8R, PG_ISO_8859_5, koi2iso, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -530,12 +565,14 @@ iso_to_win1251(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_ISO_8859_5, PG_WIN1251);
 
-	local2local(src, dest, len, PG_ISO_8859_5, PG_WIN1251, iso2win1251);
+	converted = local2local(src, dest, len, PG_ISO_8859_5, PG_WIN1251, iso2win1251, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -544,12 +581,14 @@ win1251_to_iso(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_WIN1251, PG_ISO_8859_5);
 
-	local2local(src, dest, len, PG_WIN1251, PG_ISO_8859_5, win12512iso);
+	converted = local2local(src, dest, len, PG_WIN1251, PG_ISO_8859_5, win12512iso, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -558,12 +597,14 @@ iso_to_win866(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_ISO_8859_5, PG_WIN866);
 
-	local2local(src, dest, len, PG_ISO_8859_5, PG_WIN866, iso2win866);
+	converted = local2local(src, dest, len, PG_ISO_8859_5, PG_WIN866, iso2win866, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -572,10 +613,12 @@ win866_to_iso(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_WIN866, PG_ISO_8859_5);
 
-	local2local(src, dest, len, PG_WIN866, PG_ISO_8859_5, win8662iso);
+	converted = local2local(src, dest, len, PG_WIN866, PG_ISO_8859_5, win8662iso, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
diff --git a/src/backend/utils/mb/conversion_procs/euc2004_sjis2004/euc2004_sjis2004.c b/src/backend/utils/mb/conversion_procs/euc2004_sjis2004/euc2004_sjis2004.c
index 4d7fb116cfd..a3fd35bd406 100644
--- a/src/backend/utils/mb/conversion_procs/euc2004_sjis2004/euc2004_sjis2004.c
+++ b/src/backend/utils/mb/conversion_procs/euc2004_sjis2004/euc2004_sjis2004.c
@@ -19,8 +19,8 @@ PG_MODULE_MAGIC;
 PG_FUNCTION_INFO_V1(euc_jis_2004_to_shift_jis_2004);
 PG_FUNCTION_INFO_V1(shift_jis_2004_to_euc_jis_2004);
 
-static void euc_jis_20042shift_jis_2004(const unsigned char *euc, unsigned char *p, int len);
-static void shift_jis_20042euc_jis_2004(const unsigned char *sjis, unsigned char *p, int len);
+static int	euc_jis_20042shift_jis_2004(const unsigned char *euc, unsigned char *p, int len, bool noError);
+static int	shift_jis_20042euc_jis_2004(const unsigned char *sjis, unsigned char *p, int len, bool noError);
 
 /* ----------
  * conv_proc(
@@ -28,8 +28,11 @@ static void shift_jis_20042euc_jis_2004(const unsigned char *sjis, unsigned char
  *		INTEGER,	-- destination encoding id
  *		CSTRING,	-- source string (null terminated C string)
  *		CSTRING,	-- destination string (null terminated C string)
- *		INTEGER		-- source string length
- * ) returns VOID;
+ *		INTEGER,	-- source string length
+ *		BOOL		-- if true, don't throw an error if conversion fails
+ * ) returns INTEGER;
+ *
+ * Returns the number of bytes successfully converted.
  * ----------
  */
 
@@ -39,12 +42,14 @@ euc_jis_2004_to_shift_jis_2004(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_EUC_JIS_2004, PG_SHIFT_JIS_2004);
 
-	euc_jis_20042shift_jis_2004(src, dest, len);
+	converted = euc_jis_20042shift_jis_2004(src, dest, len, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -53,20 +58,23 @@ shift_jis_2004_to_euc_jis_2004(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_SHIFT_JIS_2004, PG_EUC_JIS_2004);
 
-	shift_jis_20042euc_jis_2004(src, dest, len);
+	converted = shift_jis_20042euc_jis_2004(src, dest, len, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 /*
  * EUC_JIS_2004 -> SHIFT_JIS_2004
  */
-static void
-euc_jis_20042shift_jis_2004(const unsigned char *euc, unsigned char *p, int len)
+static int
+euc_jis_20042shift_jis_2004(const unsigned char *euc, unsigned char *p, int len, bool noError)
 {
+	const unsigned char *start = euc;
 	int			c1,
 				ku,
 				ten;
@@ -79,8 +87,12 @@ euc_jis_20042shift_jis_2004(const unsigned char *euc, unsigned char *p, int len)
 		{
 			/* ASCII */
 			if (c1 == 0)
+			{
+				if (noError)
+					break;
 				report_invalid_encoding(PG_EUC_JIS_2004,
 										(const char *) euc, len);
+			}
 			*p++ = c1;
 			euc++;
 			len--;
@@ -90,8 +102,12 @@ euc_jis_20042shift_jis_2004(const unsigned char *euc, unsigned char *p, int len)
 		l = pg_encoding_verifymbchar(PG_EUC_JIS_2004, (const char *) euc, len);
 
 		if (l < 0)
+		{
+			if (noError)
+				break;
 			report_invalid_encoding(PG_EUC_JIS_2004,
 									(const char *) euc, len);
+		}
 
 		if (c1 == SS2 && l == 2)	/* JIS X 0201 kana? */
 		{
@@ -121,8 +137,12 @@ euc_jis_20042shift_jis_2004(const unsigned char *euc, unsigned char *p, int len)
 						*p++ = (ku + 0x19b) >> 1;
 					}
 					else
+					{
+						if (noError)
+							break;
 						report_invalid_encoding(PG_EUC_JIS_2004,
 												(const char *) euc, len);
+					}
 			}
 
 			if (ku % 2)
@@ -132,8 +152,12 @@ euc_jis_20042shift_jis_2004(const unsigned char *euc, unsigned char *p, int len)
 				else if (ten >= 64 && ten <= 94)
 					*p++ = ten + 0x40;
 				else
+				{
+					if (noError)
+						break;
 					report_invalid_encoding(PG_EUC_JIS_2004,
 											(const char *) euc, len);
+				}
 			}
 			else
 				*p++ = ten + 0x9e;
@@ -149,8 +173,12 @@ euc_jis_20042shift_jis_2004(const unsigned char *euc, unsigned char *p, int len)
 			else if (ku >= 63 && ku <= 94)
 				*p++ = (ku + 0x181) >> 1;
 			else
+			{
+				if (noError)
+					break;
 				report_invalid_encoding(PG_EUC_JIS_2004,
 										(const char *) euc, len);
+			}
 
 			if (ku % 2)
 			{
@@ -159,20 +187,30 @@ euc_jis_20042shift_jis_2004(const unsigned char *euc, unsigned char *p, int len)
 				else if (ten >= 64 && ten <= 94)
 					*p++ = ten + 0x40;
 				else
+				{
+					if (noError)
+						break;
 					report_invalid_encoding(PG_EUC_JIS_2004,
 											(const char *) euc, len);
+				}
 			}
 			else
 				*p++ = ten + 0x9e;
 		}
 		else
+		{
+			if (noError)
+				break;
 			report_invalid_encoding(PG_EUC_JIS_2004,
 									(const char *) euc, len);
+		}
 
 		euc += l;
 		len -= l;
 	}
 	*p = '\0';
+
+	return euc - start;
 }
 
 /*
@@ -212,9 +250,10 @@ get_ten(int b, int *ku)
  * SHIFT_JIS_2004 ---> EUC_JIS_2004
  */
 
-static void
-shift_jis_20042euc_jis_2004(const unsigned char *sjis, unsigned char *p, int len)
+static int
+shift_jis_20042euc_jis_2004(const unsigned char *sjis, unsigned char *p, int len, bool noError)
 {
+	const unsigned char *start = sjis;
 	int			c1;
 	int			ku,
 				ten,
@@ -230,8 +269,12 @@ shift_jis_20042euc_jis_2004(const unsigned char *sjis, unsigned char *p, int len
 		{
 			/* ASCII */
 			if (c1 == 0)
+			{
+				if (noError)
+					break;
 				report_invalid_encoding(PG_SHIFT_JIS_2004,
 										(const char *) sjis, len);
+			}
 			*p++ = c1;
 			sjis++;
 			len--;
@@ -241,8 +284,12 @@ shift_jis_20042euc_jis_2004(const unsigned char *sjis, unsigned char *p, int len
 		l = pg_encoding_verifymbchar(PG_SHIFT_JIS_2004, (const char *) sjis, len);
 
 		if (l < 0 || l > len)
+		{
+			if (noError)
+				break;
 			report_invalid_encoding(PG_SHIFT_JIS_2004,
 									(const char *) sjis, len);
+		}
 
 		if (c1 >= 0xa1 && c1 <= 0xdf && l == 1)
 		{
@@ -266,8 +313,12 @@ shift_jis_20042euc_jis_2004(const unsigned char *sjis, unsigned char *p, int len
 				ku = (c1 << 1) - 0x100;
 				ten = get_ten(c2, &kubun);
 				if (ten < 0)
+				{
+					if (noError)
+						break;
 					report_invalid_encoding(PG_SHIFT_JIS_2004,
 											(const char *) sjis, len);
+				}
 				ku -= kubun;
 			}
 			else if (c1 >= 0xe0 && c1 <= 0xef)	/* plane 1 62ku-94ku */
@@ -275,9 +326,12 @@ shift_jis_20042euc_jis_2004(const unsigned char *sjis, unsigned char *p, int len
 				ku = (c1 << 1) - 0x180;
 				ten = get_ten(c2, &kubun);
 				if (ten < 0)
+				{
+					if (noError)
+						break;
 					report_invalid_encoding(PG_SHIFT_JIS_2004,
-
 											(const char *) sjis, len);
+				}
 				ku -= kubun;
 			}
 			else if (c1 >= 0xf0 && c1 <= 0xf3)	/* plane 2
@@ -286,8 +340,12 @@ shift_jis_20042euc_jis_2004(const unsigned char *sjis, unsigned char *p, int len
 				plane = 2;
 				ten = get_ten(c2, &kubun);
 				if (ten < 0)
+				{
+					if (noError)
+						break;
 					report_invalid_encoding(PG_SHIFT_JIS_2004,
 											(const char *) sjis, len);
+				}
 				switch (c1)
 				{
 					case 0xf0:
@@ -309,16 +367,24 @@ shift_jis_20042euc_jis_2004(const unsigned char *sjis, unsigned char *p, int len
 				plane = 2;
 				ten = get_ten(c2, &kubun);
 				if (ten < 0)
+				{
+					if (noError)
+						break;
 					report_invalid_encoding(PG_SHIFT_JIS_2004,
 											(const char *) sjis, len);
+				}
 				if (c1 == 0xf4 && kubun == 1)
 					ku = 15;
 				else
 					ku = (c1 << 1) - 0x19a - kubun;
 			}
 			else
+			{
+				if (noError)
+					break;
 				report_invalid_encoding(PG_SHIFT_JIS_2004,
 										(const char *) sjis, len);
+			}
 
 			if (plane == 2)
 				*p++ = SS3;
@@ -330,4 +396,6 @@ shift_jis_20042euc_jis_2004(const unsigned char *sjis, unsigned char *p, int len
 		len -= l;
 	}
 	*p = '\0';
+
+	return sjis - start;
 }
diff --git a/src/backend/utils/mb/conversion_procs/euc_cn_and_mic/euc_cn_and_mic.c b/src/backend/utils/mb/conversion_procs/euc_cn_and_mic/euc_cn_and_mic.c
index e9bb896935f..09b3c2e75bf 100644
--- a/src/backend/utils/mb/conversion_procs/euc_cn_and_mic/euc_cn_and_mic.c
+++ b/src/backend/utils/mb/conversion_procs/euc_cn_and_mic/euc_cn_and_mic.c
@@ -26,13 +26,16 @@ PG_FUNCTION_INFO_V1(mic_to_euc_cn);
  *		INTEGER,	-- destination encoding id
  *		CSTRING,	-- source string (null terminated C string)
  *		CSTRING,	-- destination string (null terminated C string)
- *		INTEGER		-- source string length
- * ) returns VOID;
+ *		INTEGER,	-- source string length
+ *		BOOL		-- if true, don't throw an error if conversion fails
+ * ) returns INTEGER;
+ *
+ * Returns the number of bytes successfully converted.
  * ----------
  */
 
-static void euc_cn2mic(const unsigned char *euc, unsigned char *p, int len);
-static void mic2euc_cn(const unsigned char *mic, unsigned char *p, int len);
+static int	euc_cn2mic(const unsigned char *euc, unsigned char *p, int len, bool noError);
+static int	mic2euc_cn(const unsigned char *mic, unsigned char *p, int len, bool noError);
 
 Datum
 euc_cn_to_mic(PG_FUNCTION_ARGS)
@@ -40,12 +43,14 @@ euc_cn_to_mic(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_EUC_CN, PG_MULE_INTERNAL);
 
-	euc_cn2mic(src, dest, len);
+	converted = euc_cn2mic(src, dest, len, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -54,20 +59,23 @@ mic_to_euc_cn(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_MULE_INTERNAL, PG_EUC_CN);
 
-	mic2euc_cn(src, dest, len);
+	converted = mic2euc_cn(src, dest, len, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 /*
  * EUC_CN ---> MIC
  */
-static void
-euc_cn2mic(const unsigned char *euc, unsigned char *p, int len)
+static int
+euc_cn2mic(const unsigned char *euc, unsigned char *p, int len, bool noError)
 {
+	const unsigned char *start = euc;
 	int			c1;
 
 	while (len > 0)
@@ -76,7 +84,11 @@ euc_cn2mic(const unsigned char *euc, unsigned char *p, int len)
 		if (IS_HIGHBIT_SET(c1))
 		{
 			if (len < 2 || !IS_HIGHBIT_SET(euc[1]))
+			{
+				if (noError)
+					break;
 				report_invalid_encoding(PG_EUC_CN, (const char *) euc, len);
+			}
 			*p++ = LC_GB2312_80;
 			*p++ = c1;
 			*p++ = euc[1];
@@ -86,21 +98,28 @@ euc_cn2mic(const unsigned char *euc, unsigned char *p, int len)
 		else
 		{						/* should be ASCII */
 			if (c1 == 0)
+			{
+				if (noError)
+					break;
 				report_invalid_encoding(PG_EUC_CN, (const char *) euc, len);
+			}
 			*p++ = c1;
 			euc++;
 			len--;
 		}
 	}
 	*p = '\0';
+
+	return euc - start;
 }
 
 /*
  * MIC ---> EUC_CN
  */
-static void
-mic2euc_cn(const unsigned char *mic, unsigned char *p, int len)
+static int
+mic2euc_cn(const unsigned char *mic, unsigned char *p, int len, bool noError)
 {
+	const unsigned char *start = mic;
 	int			c1;
 
 	while (len > 0)
@@ -109,11 +128,19 @@ mic2euc_cn(const unsigned char *mic, unsigned char *p, int len)
 		if (IS_HIGHBIT_SET(c1))
 		{
 			if (c1 != LC_GB2312_80)
+			{
+				if (noError)
+					break;
 				report_untranslatable_char(PG_MULE_INTERNAL, PG_EUC_CN,
 										   (const char *) mic, len);
+			}
 			if (len < 3 || !IS_HIGHBIT_SET(mic[1]) || !IS_HIGHBIT_SET(mic[2]))
+			{
+				if (noError)
+					break;
 				report_invalid_encoding(PG_MULE_INTERNAL,
 										(const char *) mic, len);
+			}
 			mic++;
 			*p++ = *mic++;
 			*p++ = *mic++;
@@ -122,12 +149,18 @@ mic2euc_cn(const unsigned char *mic, unsigned char *p, int len)
 		else
 		{						/* should be ASCII */
 			if (c1 == 0)
+			{
+				if (noError)
+					break;
 				report_invalid_encoding(PG_MULE_INTERNAL,
 										(const char *) mic, len);
+			}
 			*p++ = c1;
 			mic++;
 			len--;
 		}
 	}
 	*p = '\0';
+
+	return mic - start;
 }
diff --git a/src/backend/utils/mb/conversion_procs/euc_jp_and_sjis/euc_jp_and_sjis.c b/src/backend/utils/mb/conversion_procs/euc_jp_and_sjis/euc_jp_and_sjis.c
index 5059f917a98..2e68708893d 100644
--- a/src/backend/utils/mb/conversion_procs/euc_jp_and_sjis/euc_jp_and_sjis.c
+++ b/src/backend/utils/mb/conversion_procs/euc_jp_and_sjis/euc_jp_and_sjis.c
@@ -42,17 +42,20 @@ PG_FUNCTION_INFO_V1(mic_to_sjis);
  *		INTEGER,	-- destination encoding id
  *		CSTRING,	-- source string (null terminated C string)
  *		CSTRING,	-- destination string (null terminated C string)
- *		INTEGER		-- source string length
- * ) returns VOID;
+ *		INTEGER,	-- source string length
+ *		BOOL		-- if true, don't throw an error if conversion fails
+ * ) returns INTEGER;
+ *
+ * Returns the number of bytes successfully converted.
  * ----------
  */
 
-static void sjis2mic(const unsigned char *sjis, unsigned char *p, int len);
-static void mic2sjis(const unsigned char *mic, unsigned char *p, int len);
-static void euc_jp2mic(const unsigned char *euc, unsigned char *p, int len);
-static void mic2euc_jp(const unsigned char *mic, unsigned char *p, int len);
-static void euc_jp2sjis(const unsigned char *mic, unsigned char *p, int len);
-static void sjis2euc_jp(const unsigned char *mic, unsigned char *p, int len);
+static int	sjis2mic(const unsigned char *sjis, unsigned char *p, int len, bool noError);
+static int	mic2sjis(const unsigned char *mic, unsigned char *p, int len, bool noError);
+static int	euc_jp2mic(const unsigned char *euc, unsigned char *p, int len, bool noError);
+static int	mic2euc_jp(const unsigned char *mic, unsigned char *p, int len, bool noError);
+static int	euc_jp2sjis(const unsigned char *mic, unsigned char *p, int len, bool noError);
+static int	sjis2euc_jp(const unsigned char *mic, unsigned char *p, int len, bool noError);
 
 Datum
 euc_jp_to_sjis(PG_FUNCTION_ARGS)
@@ -60,12 +63,14 @@ euc_jp_to_sjis(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_EUC_JP, PG_SJIS);
 
-	euc_jp2sjis(src, dest, len);
+	converted = euc_jp2sjis(src, dest, len, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -74,12 +79,14 @@ sjis_to_euc_jp(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_SJIS, PG_EUC_JP);
 
-	sjis2euc_jp(src, dest, len);
+	converted = sjis2euc_jp(src, dest, len, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -88,12 +95,14 @@ euc_jp_to_mic(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_EUC_JP, PG_MULE_INTERNAL);
 
-	euc_jp2mic(src, dest, len);
+	converted = euc_jp2mic(src, dest, len, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -102,12 +111,14 @@ mic_to_euc_jp(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_MULE_INTERNAL, PG_EUC_JP);
 
-	mic2euc_jp(src, dest, len);
+	converted = mic2euc_jp(src, dest, len, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -116,12 +127,14 @@ sjis_to_mic(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_SJIS, PG_MULE_INTERNAL);
 
-	sjis2mic(src, dest, len);
+	converted = sjis2mic(src, dest, len, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -130,20 +143,23 @@ mic_to_sjis(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_MULE_INTERNAL, PG_SJIS);
 
-	mic2sjis(src, dest, len);
+	converted = mic2sjis(src, dest, len, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 /*
  * SJIS ---> MIC
  */
-static void
-sjis2mic(const unsigned char *sjis, unsigned char *p, int len)
+static int
+sjis2mic(const unsigned char *sjis, unsigned char *p, int len, bool noError)
 {
+	const unsigned char *start = sjis;
 	int			c1,
 				c2,
 				i,
@@ -167,7 +183,11 @@ sjis2mic(const unsigned char *sjis, unsigned char *p, int len)
 			 * JIS X0208, X0212, user defined extended characters
 			 */
 			if (len < 2 || !ISSJISHEAD(c1) || !ISSJISTAIL(sjis[1]))
+			{
+				if (noError)
+					break;
 				report_invalid_encoding(PG_SJIS, (const char *) sjis, len);
+			}
 			c2 = sjis[1];
 			k = (c1 << 8) + c2;
 			if (k >= 0xed40 && k < 0xf040)
@@ -257,21 +277,28 @@ sjis2mic(const unsigned char *sjis, unsigned char *p, int len)
 		else
 		{						/* should be ASCII */
 			if (c1 == 0)
+			{
+				if (noError)
+					break;
 				report_invalid_encoding(PG_SJIS, (const char *) sjis, len);
+			}
 			*p++ = c1;
 			sjis++;
 			len--;
 		}
 	}
 	*p = '\0';
+
+	return sjis - start;
 }
 
 /*
  * MIC ---> SJIS
  */
-static void
-mic2sjis(const unsigned char *mic, unsigned char *p, int len)
+static int
+mic2sjis(const unsigned char *mic, unsigned char *p, int len, bool noError)
 {
+	const unsigned char *start = mic;
 	int			c1,
 				c2,
 				k,
@@ -284,8 +311,12 @@ mic2sjis(const unsigned char *mic, unsigned char *p, int len)
 		{
 			/* ASCII */
 			if (c1 == 0)
+			{
+				if (noError)
+					break;
 				report_invalid_encoding(PG_MULE_INTERNAL,
 										(const char *) mic, len);
+			}
 			*p++ = c1;
 			mic++;
 			len--;
@@ -293,8 +324,12 @@ mic2sjis(const unsigned char *mic, unsigned char *p, int len)
 		}
 		l = pg_encoding_verifymbchar(PG_MULE_INTERNAL, (const char *) mic, len);
 		if (l < 0)
+		{
+			if (noError)
+				break;
 			report_invalid_encoding(PG_MULE_INTERNAL,
 									(const char *) mic, len);
+		}
 		if (c1 == LC_JISX0201K)
 			*p++ = mic[1];
 		else if (c1 == LC_JISX0208)
@@ -350,20 +385,27 @@ mic2sjis(const unsigned char *mic, unsigned char *p, int len)
 			}
 		}
 		else
+		{
+			if (noError)
+				break;
 			report_untranslatable_char(PG_MULE_INTERNAL, PG_SJIS,
 									   (const char *) mic, len);
+		}
 		mic += l;
 		len -= l;
 	}
 	*p = '\0';
+
+	return mic - start;
 }
 
 /*
  * EUC_JP ---> MIC
  */
-static void
-euc_jp2mic(const unsigned char *euc, unsigned char *p, int len)
+static int
+euc_jp2mic(const unsigned char *euc, unsigned char *p, int len, bool noError)
 {
+	const unsigned char *start = euc;
 	int			c1;
 	int			l;
 
@@ -374,8 +416,12 @@ euc_jp2mic(const unsigned char *euc, unsigned char *p, int len)
 		{
 			/* ASCII */
 			if (c1 == 0)
+			{
+				if (noError)
+					break;
 				report_invalid_encoding(PG_EUC_JP,
 										(const char *) euc, len);
+			}
 			*p++ = c1;
 			euc++;
 			len--;
@@ -383,8 +429,12 @@ euc_jp2mic(const unsigned char *euc, unsigned char *p, int len)
 		}
 		l = pg_encoding_verifymbchar(PG_EUC_JP, (const char *) euc, len);
 		if (l < 0)
+		{
+			if (noError)
+				break;
 			report_invalid_encoding(PG_EUC_JP,
 									(const char *) euc, len);
+		}
 		if (c1 == SS2)
 		{						/* 1 byte kana? */
 			*p++ = LC_JISX0201K;
@@ -406,14 +456,17 @@ euc_jp2mic(const unsigned char *euc, unsigned char *p, int len)
 		len -= l;
 	}
 	*p = '\0';
+
+	return euc - start;
 }
 
 /*
  * MIC ---> EUC_JP
  */
-static void
-mic2euc_jp(const unsigned char *mic, unsigned char *p, int len)
+static int
+mic2euc_jp(const unsigned char *mic, unsigned char *p, int len, bool noError)
 {
+	const unsigned char *start = mic;
 	int			c1;
 	int			l;
 
@@ -424,8 +477,12 @@ mic2euc_jp(const unsigned char *mic, unsigned char *p, int len)
 		{
 			/* ASCII */
 			if (c1 == 0)
+			{
+				if (noError)
+					break;
 				report_invalid_encoding(PG_MULE_INTERNAL,
 										(const char *) mic, len);
+			}
 			*p++ = c1;
 			mic++;
 			len--;
@@ -433,8 +490,12 @@ mic2euc_jp(const unsigned char *mic, unsigned char *p, int len)
 		}
 		l = pg_encoding_verifymbchar(PG_MULE_INTERNAL, (const char *) mic, len);
 		if (l < 0)
+		{
+			if (noError)
+				break;
 			report_invalid_encoding(PG_MULE_INTERNAL,
 									(const char *) mic, len);
+		}
 		if (c1 == LC_JISX0201K)
 		{
 			*p++ = SS2;
@@ -452,20 +513,27 @@ mic2euc_jp(const unsigned char *mic, unsigned char *p, int len)
 			*p++ = mic[2];
 		}
 		else
+		{
+			if (noError)
+				break;
 			report_untranslatable_char(PG_MULE_INTERNAL, PG_EUC_JP,
 									   (const char *) mic, len);
+		}
 		mic += l;
 		len -= l;
 	}
 	*p = '\0';
+
+	return mic - start;
 }
 
 /*
  * EUC_JP -> SJIS
  */
-static void
-euc_jp2sjis(const unsigned char *euc, unsigned char *p, int len)
+static int
+euc_jp2sjis(const unsigned char *euc, unsigned char *p, int len, bool noError)
 {
+	const unsigned char *start = euc;
 	int			c1,
 				c2,
 				k;
@@ -478,8 +546,12 @@ euc_jp2sjis(const unsigned char *euc, unsigned char *p, int len)
 		{
 			/* ASCII */
 			if (c1 == 0)
+			{
+				if (noError)
+					break;
 				report_invalid_encoding(PG_EUC_JP,
 										(const char *) euc, len);
+			}
 			*p++ = c1;
 			euc++;
 			len--;
@@ -487,8 +559,12 @@ euc_jp2sjis(const unsigned char *euc, unsigned char *p, int len)
 		}
 		l = pg_encoding_verifymbchar(PG_EUC_JP, (const char *) euc, len);
 		if (l < 0)
+		{
+			if (noError)
+				break;
 			report_invalid_encoding(PG_EUC_JP,
 									(const char *) euc, len);
+		}
 		if (c1 == SS2)
 		{
 			/* hankaku kana? */
@@ -551,14 +627,17 @@ euc_jp2sjis(const unsigned char *euc, unsigned char *p, int len)
 		len -= l;
 	}
 	*p = '\0';
+
+	return euc - start;
 }
 
 /*
  * SJIS ---> EUC_JP
  */
-static void
-sjis2euc_jp(const unsigned char *sjis, unsigned char *p, int len)
+static int
+sjis2euc_jp(const unsigned char *sjis, unsigned char *p, int len, bool noError)
 {
+	const unsigned char *start = sjis;
 	int			c1,
 				c2,
 				i,
@@ -573,8 +652,12 @@ sjis2euc_jp(const unsigned char *sjis, unsigned char *p, int len)
 		{
 			/* ASCII */
 			if (c1 == 0)
+			{
+				if (noError)
+					break;
 				report_invalid_encoding(PG_SJIS,
 										(const char *) sjis, len);
+			}
 			*p++ = c1;
 			sjis++;
 			len--;
@@ -582,8 +665,12 @@ sjis2euc_jp(const unsigned char *sjis, unsigned char *p, int len)
 		}
 		l = pg_encoding_verifymbchar(PG_SJIS, (const char *) sjis, len);
 		if (l < 0)
+		{
+			if (noError)
+				break;
 			report_invalid_encoding(PG_SJIS,
 									(const char *) sjis, len);
+		}
 		if (c1 >= 0xa1 && c1 <= 0xdf)
 		{
 			/* JIS X0201 (1 byte kana) */
@@ -680,4 +767,6 @@ sjis2euc_jp(const unsigned char *sjis, unsigned char *p, int len)
 		len -= l;
 	}
 	*p = '\0';
+
+	return sjis - start;
 }
diff --git a/src/backend/utils/mb/conversion_procs/euc_kr_and_mic/euc_kr_and_mic.c b/src/backend/utils/mb/conversion_procs/euc_kr_and_mic/euc_kr_and_mic.c
index ac823d6c270..3b85f0c1861 100644
--- a/src/backend/utils/mb/conversion_procs/euc_kr_and_mic/euc_kr_and_mic.c
+++ b/src/backend/utils/mb/conversion_procs/euc_kr_and_mic/euc_kr_and_mic.c
@@ -26,13 +26,16 @@ PG_FUNCTION_INFO_V1(mic_to_euc_kr);
  *		INTEGER,	-- destination encoding id
  *		CSTRING,	-- source string (null terminated C string)
  *		CSTRING,	-- destination string (null terminated C string)
- *		INTEGER		-- source string length
- * ) returns VOID;
+ *		INTEGER,	-- source string length
+ *		BOOL		-- if true, don't throw an error if conversion fails
+ * ) returns INTEGER;
+ *
+ * Returns the number of bytes successfully converted.
  * ----------
  */
 
-static void euc_kr2mic(const unsigned char *euc, unsigned char *p, int len);
-static void mic2euc_kr(const unsigned char *mic, unsigned char *p, int len);
+static int	euc_kr2mic(const unsigned char *euc, unsigned char *p, int len, bool noError);
+static int	mic2euc_kr(const unsigned char *mic, unsigned char *p, int len, bool noError);
 
 Datum
 euc_kr_to_mic(PG_FUNCTION_ARGS)
@@ -40,12 +43,14 @@ euc_kr_to_mic(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_EUC_KR, PG_MULE_INTERNAL);
 
-	euc_kr2mic(src, dest, len);
+	converted = euc_kr2mic(src, dest, len, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -54,20 +59,23 @@ mic_to_euc_kr(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_MULE_INTERNAL, PG_EUC_KR);
 
-	mic2euc_kr(src, dest, len);
+	converted = mic2euc_kr(src, dest, len, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 /*
  * EUC_KR ---> MIC
  */
-static void
-euc_kr2mic(const unsigned char *euc, unsigned char *p, int len)
+static int
+euc_kr2mic(const unsigned char *euc, unsigned char *p, int len, bool noError)
 {
+	const unsigned char *start = euc;
 	int			c1;
 	int			l;
 
@@ -78,8 +86,12 @@ euc_kr2mic(const unsigned char *euc, unsigned char *p, int len)
 		{
 			l = pg_encoding_verifymbchar(PG_EUC_KR, (const char *) euc, len);
 			if (l != 2)
+			{
+				if (noError)
+					break;
 				report_invalid_encoding(PG_EUC_KR,
 										(const char *) euc, len);
+			}
 			*p++ = LC_KS5601;
 			*p++ = c1;
 			*p++ = euc[1];
@@ -89,22 +101,29 @@ euc_kr2mic(const unsigned char *euc, unsigned char *p, int len)
 		else
 		{						/* should be ASCII */
 			if (c1 == 0)
+			{
+				if (noError)
+					break;
 				report_invalid_encoding(PG_EUC_KR,
 										(const char *) euc, len);
+			}
 			*p++ = c1;
 			euc++;
 			len--;
 		}
 	}
 	*p = '\0';
+
+	return euc - start;
 }
 
 /*
  * MIC ---> EUC_KR
  */
-static void
-mic2euc_kr(const unsigned char *mic, unsigned char *p, int len)
+static int
+mic2euc_kr(const unsigned char *mic, unsigned char *p, int len, bool noError)
 {
+	const unsigned char *start = mic;
 	int			c1;
 	int			l;
 
@@ -115,8 +134,12 @@ mic2euc_kr(const unsigned char *mic, unsigned char *p, int len)
 		{
 			/* ASCII */
 			if (c1 == 0)
+			{
+				if (noError)
+					break;
 				report_invalid_encoding(PG_MULE_INTERNAL,
 										(const char *) mic, len);
+			}
 			*p++ = c1;
 			mic++;
 			len--;
@@ -124,18 +147,28 @@ mic2euc_kr(const unsigned char *mic, unsigned char *p, int len)
 		}
 		l = pg_encoding_verifymbchar(PG_MULE_INTERNAL, (const char *) mic, len);
 		if (l < 0)
+		{
+			if (noError)
+				break;
 			report_invalid_encoding(PG_MULE_INTERNAL,
 									(const char *) mic, len);
+		}
 		if (c1 == LC_KS5601)
 		{
 			*p++ = mic[1];
 			*p++ = mic[2];
 		}
 		else
+		{
+			if (noError)
+				break;
 			report_untranslatable_char(PG_MULE_INTERNAL, PG_EUC_KR,
 									   (const char *) mic, len);
+		}
 		mic += l;
 		len -= l;
 	}
 	*p = '\0';
+
+	return mic - start;
 }
diff --git a/src/backend/utils/mb/conversion_procs/euc_tw_and_big5/euc_tw_and_big5.c b/src/backend/utils/mb/conversion_procs/euc_tw_and_big5/euc_tw_and_big5.c
index 66c242d7f36..4bf8acda99f 100644
--- a/src/backend/utils/mb/conversion_procs/euc_tw_and_big5/euc_tw_and_big5.c
+++ b/src/backend/utils/mb/conversion_procs/euc_tw_and_big5/euc_tw_and_big5.c
@@ -32,17 +32,20 @@ PG_FUNCTION_INFO_V1(mic_to_big5);
  *		INTEGER,	-- destination encoding id
  *		CSTRING,	-- source string (null terminated C string)
  *		CSTRING,	-- destination string (null terminated C string)
- *		INTEGER		-- source string length
- * ) returns VOID;
+ *		INTEGER,	-- source string length
+ *		BOOL		-- if true, don't throw an error if conversion fails
+ * ) returns INTEGER;
+ *
+ * Returns the number of bytes successfully converted.
  * ----------
  */
 
-static void euc_tw2big5(const unsigned char *euc, unsigned char *p, int len);
-static void big52euc_tw(const unsigned char *euc, unsigned char *p, int len);
-static void big52mic(const unsigned char *big5, unsigned char *p, int len);
-static void mic2big5(const unsigned char *mic, unsigned char *p, int len);
-static void euc_tw2mic(const unsigned char *euc, unsigned char *p, int len);
-static void mic2euc_tw(const unsigned char *mic, unsigned char *p, int len);
+static int	euc_tw2big5(const unsigned char *euc, unsigned char *p, int len, bool noError);
+static int	big52euc_tw(const unsigned char *euc, unsigned char *p, int len, bool noError);
+static int	big52mic(const unsigned char *big5, unsigned char *p, int len, bool noError);
+static int	mic2big5(const unsigned char *mic, unsigned char *p, int len, bool noError);
+static int	euc_tw2mic(const unsigned char *euc, unsigned char *p, int len, bool noError);
+static int	mic2euc_tw(const unsigned char *mic, unsigned char *p, int len, bool noError);
 
 Datum
 euc_tw_to_big5(PG_FUNCTION_ARGS)
@@ -50,12 +53,14 @@ euc_tw_to_big5(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_EUC_TW, PG_BIG5);
 
-	euc_tw2big5(src, dest, len);
+	converted = euc_tw2big5(src, dest, len, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -64,12 +69,14 @@ big5_to_euc_tw(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_BIG5, PG_EUC_TW);
 
-	big52euc_tw(src, dest, len);
+	converted = big52euc_tw(src, dest, len, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -78,12 +85,14 @@ euc_tw_to_mic(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_EUC_TW, PG_MULE_INTERNAL);
 
-	euc_tw2mic(src, dest, len);
+	converted = euc_tw2mic(src, dest, len, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -92,12 +101,14 @@ mic_to_euc_tw(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_MULE_INTERNAL, PG_EUC_TW);
 
-	mic2euc_tw(src, dest, len);
+	converted = mic2euc_tw(src, dest, len, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -106,12 +117,14 @@ big5_to_mic(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_BIG5, PG_MULE_INTERNAL);
 
-	big52mic(src, dest, len);
+	converted = big52mic(src, dest, len, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -120,21 +133,24 @@ mic_to_big5(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_MULE_INTERNAL, PG_BIG5);
 
-	mic2big5(src, dest, len);
+	converted = mic2big5(src, dest, len, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 
 /*
  * EUC_TW ---> Big5
  */
-static void
-euc_tw2big5(const unsigned char *euc, unsigned char *p, int len)
+static int
+euc_tw2big5(const unsigned char *euc, unsigned char *p, int len, bool noError)
 {
+	const unsigned char *start = euc;
 	unsigned char c1;
 	unsigned short big5buf,
 				cnsBuf;
@@ -149,8 +165,12 @@ euc_tw2big5(const unsigned char *euc, unsigned char *p, int len)
 			/* Verify and decode the next EUC_TW input character */
 			l = pg_encoding_verifymbchar(PG_EUC_TW, (const char *) euc, len);
 			if (l < 0)
+			{
+				if (noError)
+					break;
 				report_invalid_encoding(PG_EUC_TW,
 										(const char *) euc, len);
+			}
 			if (c1 == SS2)
 			{
 				c1 = euc[1];	/* plane No. */
@@ -171,8 +191,12 @@ euc_tw2big5(const unsigned char *euc, unsigned char *p, int len)
 			/* Write it out in Big5 */
 			big5buf = CNStoBIG5(cnsBuf, lc);
 			if (big5buf == 0)
+			{
+				if (noError)
+					break;
 				report_untranslatable_char(PG_EUC_TW, PG_BIG5,
 										   (const char *) euc, len);
+			}
 			*p++ = (big5buf >> 8) & 0x00ff;
 			*p++ = big5buf & 0x00ff;
 
@@ -182,22 +206,29 @@ euc_tw2big5(const unsigned char *euc, unsigned char *p, int len)
 		else
 		{						/* should be ASCII */
 			if (c1 == 0)
+			{
+				if (noError)
+					break;
 				report_invalid_encoding(PG_EUC_TW,
 										(const char *) euc, len);
+			}
 			*p++ = c1;
 			euc++;
 			len--;
 		}
 	}
 	*p = '\0';
+
+	return euc - start;
 }
 
 /*
  * Big5 ---> EUC_TW
  */
-static void
-big52euc_tw(const unsigned char *big5, unsigned char *p, int len)
+static int
+big52euc_tw(const unsigned char *big5, unsigned char *p, int len, bool noError)
 {
+	const unsigned char *start = big5;
 	unsigned short c1;
 	unsigned short big5buf,
 				cnsBuf;
@@ -212,8 +243,12 @@ big52euc_tw(const unsigned char *big5, unsigned char *p, int len)
 		{
 			l = pg_encoding_verifymbchar(PG_BIG5, (const char *) big5, len);
 			if (l < 0)
+			{
+				if (noError)
+					break;
 				report_invalid_encoding(PG_BIG5,
 										(const char *) big5, len);
+			}
 			big5buf = (c1 << 8) | big5[1];
 			cnsBuf = BIG5toCNS(big5buf, &lc);
 
@@ -237,8 +272,12 @@ big52euc_tw(const unsigned char *big5, unsigned char *p, int len)
 				*p++ = cnsBuf & 0x00ff;
 			}
 			else
+			{
+				if (noError)
+					break;
 				report_untranslatable_char(PG_BIG5, PG_EUC_TW,
 										   (const char *) big5, len);
+			}
 
 			big5 += l;
 			len -= l;
@@ -256,14 +295,17 @@ big52euc_tw(const unsigned char *big5, unsigned char *p, int len)
 		}
 	}
 	*p = '\0';
+
+	return big5 - start;
 }
 
 /*
  * EUC_TW ---> MIC
  */
-static void
-euc_tw2mic(const unsigned char *euc, unsigned char *p, int len)
+static int
+euc_tw2mic(const unsigned char *euc, unsigned char *p, int len, bool noError)
 {
+	const unsigned char *start = euc;
 	int			c1;
 	int			l;
 
@@ -274,8 +316,12 @@ euc_tw2mic(const unsigned char *euc, unsigned char *p, int len)
 		{
 			l = pg_encoding_verifymbchar(PG_EUC_TW, (const char *) euc, len);
 			if (l < 0)
+			{
+				if (noError)
+					break;
 				report_invalid_encoding(PG_EUC_TW,
 										(const char *) euc, len);
+			}
 			if (c1 == SS2)
 			{
 				c1 = euc[1];	/* plane No. */
@@ -304,22 +350,29 @@ euc_tw2mic(const unsigned char *euc, unsigned char *p, int len)
 		else
 		{						/* should be ASCII */
 			if (c1 == 0)
+			{
+				if (noError)
+					break;
 				report_invalid_encoding(PG_EUC_TW,
 										(const char *) euc, len);
+			}
 			*p++ = c1;
 			euc++;
 			len--;
 		}
 	}
 	*p = '\0';
+
+	return euc - start;
 }
 
 /*
  * MIC ---> EUC_TW
  */
-static void
-mic2euc_tw(const unsigned char *mic, unsigned char *p, int len)
+static int
+mic2euc_tw(const unsigned char *mic, unsigned char *p, int len, bool noError)
 {
+	const unsigned char *start = mic;
 	int			c1;
 	int			l;
 
@@ -330,8 +383,12 @@ mic2euc_tw(const unsigned char *mic, unsigned char *p, int len)
 		{
 			/* ASCII */
 			if (c1 == 0)
+			{
+				if (noError)
+					break;
 				report_invalid_encoding(PG_MULE_INTERNAL,
 										(const char *) mic, len);
+			}
 			*p++ = c1;
 			mic++;
 			len--;
@@ -339,8 +396,12 @@ mic2euc_tw(const unsigned char *mic, unsigned char *p, int len)
 		}
 		l = pg_encoding_verifymbchar(PG_MULE_INTERNAL, (const char *) mic, len);
 		if (l < 0)
+		{
+			if (noError)
+				break;
 			report_invalid_encoding(PG_MULE_INTERNAL,
 									(const char *) mic, len);
+		}
 		if (c1 == LC_CNS11643_1)
 		{
 			*p++ = mic[1];
@@ -362,20 +423,27 @@ mic2euc_tw(const unsigned char *mic, unsigned char *p, int len)
 			*p++ = mic[3];
 		}
 		else
+		{
+			if (noError)
+				break;
 			report_untranslatable_char(PG_MULE_INTERNAL, PG_EUC_TW,
 									   (const char *) mic, len);
+		}
 		mic += l;
 		len -= l;
 	}
 	*p = '\0';
+
+	return mic - start;
 }
 
 /*
  * Big5 ---> MIC
  */
-static void
-big52mic(const unsigned char *big5, unsigned char *p, int len)
+static int
+big52mic(const unsigned char *big5, unsigned char *p, int len, bool noError)
 {
+	const unsigned char *start = big5;
 	unsigned short c1;
 	unsigned short big5buf,
 				cnsBuf;
@@ -389,8 +457,12 @@ big52mic(const unsigned char *big5, unsigned char *p, int len)
 		{
 			/* ASCII */
 			if (c1 == 0)
+			{
+				if (noError)
+					break;
 				report_invalid_encoding(PG_BIG5,
 										(const char *) big5, len);
+			}
 			*p++ = c1;
 			big5++;
 			len--;
@@ -398,8 +470,12 @@ big52mic(const unsigned char *big5, unsigned char *p, int len)
 		}
 		l = pg_encoding_verifymbchar(PG_BIG5, (const char *) big5, len);
 		if (l < 0)
+		{
+			if (noError)
+				break;
 			report_invalid_encoding(PG_BIG5,
 									(const char *) big5, len);
+		}
 		big5buf = (c1 << 8) | big5[1];
 		cnsBuf = BIG5toCNS(big5buf, &lc);
 		if (lc != 0)
@@ -412,20 +488,27 @@ big52mic(const unsigned char *big5, unsigned char *p, int len)
 			*p++ = cnsBuf & 0x00ff;
 		}
 		else
+		{
+			if (noError)
+				break;
 			report_untranslatable_char(PG_BIG5, PG_MULE_INTERNAL,
 									   (const char *) big5, len);
+		}
 		big5 += l;
 		len -= l;
 	}
 	*p = '\0';
+
+	return big5 - start;
 }
 
 /*
  * MIC ---> Big5
  */
-static void
-mic2big5(const unsigned char *mic, unsigned char *p, int len)
+static int
+mic2big5(const unsigned char *mic, unsigned char *p, int len, bool noError)
 {
+	const unsigned char *start = mic;
 	unsigned short c1;
 	unsigned short big5buf,
 				cnsBuf;
@@ -438,8 +521,12 @@ mic2big5(const unsigned char *mic, unsigned char *p, int len)
 		{
 			/* ASCII */
 			if (c1 == 0)
+			{
+				if (noError)
+					break;
 				report_invalid_encoding(PG_MULE_INTERNAL,
 										(const char *) mic, len);
+			}
 			*p++ = c1;
 			mic++;
 			len--;
@@ -447,8 +534,12 @@ mic2big5(const unsigned char *mic, unsigned char *p, int len)
 		}
 		l = pg_encoding_verifymbchar(PG_MULE_INTERNAL, (const char *) mic, len);
 		if (l < 0)
+		{
+			if (noError)
+				break;
 			report_invalid_encoding(PG_MULE_INTERNAL,
 									(const char *) mic, len);
+		}
 		if (c1 == LC_CNS11643_1 || c1 == LC_CNS11643_2 || c1 == LCPRV2_B)
 		{
 			if (c1 == LCPRV2_B)
@@ -462,16 +553,26 @@ mic2big5(const unsigned char *mic, unsigned char *p, int len)
 			}
 			big5buf = CNStoBIG5(cnsBuf, c1);
 			if (big5buf == 0)
+			{
+				if (noError)
+					break;
 				report_untranslatable_char(PG_MULE_INTERNAL, PG_BIG5,
 										   (const char *) mic, len);
+			}
 			*p++ = (big5buf >> 8) & 0x00ff;
 			*p++ = big5buf & 0x00ff;
 		}
 		else
+		{
+			if (noError)
+				break;
 			report_untranslatable_char(PG_MULE_INTERNAL, PG_BIG5,
 									   (const char *) mic, len);
+		}
 		mic += l;
 		len -= l;
 	}
 	*p = '\0';
+
+	return mic - start;
 }
diff --git a/src/backend/utils/mb/conversion_procs/latin2_and_win1250/latin2_and_win1250.c b/src/backend/utils/mb/conversion_procs/latin2_and_win1250/latin2_and_win1250.c
index 2e28e6780a5..8610fcb69aa 100644
--- a/src/backend/utils/mb/conversion_procs/latin2_and_win1250/latin2_and_win1250.c
+++ b/src/backend/utils/mb/conversion_procs/latin2_and_win1250/latin2_and_win1250.c
@@ -30,8 +30,11 @@ PG_FUNCTION_INFO_V1(win1250_to_latin2);
  *		INTEGER,	-- destination encoding id
  *		CSTRING,	-- source string (null terminated C string)
  *		CSTRING,	-- destination string (null terminated C string)
- *		INTEGER		-- source string length
- * ) returns VOID;
+ *		INTEGER,	-- source string length
+ *		BOOL		-- if true, don't throw an error if conversion fails
+ * ) returns INTEGER;
+ *
+ * Returns the number of bytes successfully converted.
  * ----------
  */
 
@@ -82,12 +85,14 @@ latin2_to_mic(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_LATIN2, PG_MULE_INTERNAL);
 
-	latin2mic(src, dest, len, LC_ISO8859_2, PG_LATIN2);
+	converted = latin2mic(src, dest, len, LC_ISO8859_2, PG_LATIN2, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -96,12 +101,14 @@ mic_to_latin2(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_MULE_INTERNAL, PG_LATIN2);
 
-	mic2latin(src, dest, len, LC_ISO8859_2, PG_LATIN2);
+	converted = mic2latin(src, dest, len, LC_ISO8859_2, PG_LATIN2, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -110,13 +117,15 @@ win1250_to_mic(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_WIN1250, PG_MULE_INTERNAL);
 
-	latin2mic_with_table(src, dest, len, LC_ISO8859_2, PG_WIN1250,
-						 win1250_2_iso88592);
+	converted = latin2mic_with_table(src, dest, len, LC_ISO8859_2, PG_WIN1250,
+									 win1250_2_iso88592, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -125,13 +134,15 @@ mic_to_win1250(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_MULE_INTERNAL, PG_WIN1250);
 
-	mic2latin_with_table(src, dest, len, LC_ISO8859_2, PG_WIN1250,
-						 iso88592_2_win1250);
+	converted = mic2latin_with_table(src, dest, len, LC_ISO8859_2, PG_WIN1250,
+									 iso88592_2_win1250, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -140,12 +151,15 @@ latin2_to_win1250(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_LATIN2, PG_WIN1250);
 
-	local2local(src, dest, len, PG_LATIN2, PG_WIN1250, iso88592_2_win1250);
+	converted = local2local(src, dest, len, PG_LATIN2, PG_WIN1250,
+							iso88592_2_win1250, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -154,10 +168,13 @@ win1250_to_latin2(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_WIN1250, PG_LATIN2);
 
-	local2local(src, dest, len, PG_WIN1250, PG_LATIN2, win1250_2_iso88592);
+	converted = local2local(src, dest, len, PG_WIN1250, PG_LATIN2,
+							win1250_2_iso88592, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
diff --git a/src/backend/utils/mb/conversion_procs/latin_and_mic/latin_and_mic.c b/src/backend/utils/mb/conversion_procs/latin_and_mic/latin_and_mic.c
index bc651410f21..bff27d1c295 100644
--- a/src/backend/utils/mb/conversion_procs/latin_and_mic/latin_and_mic.c
+++ b/src/backend/utils/mb/conversion_procs/latin_and_mic/latin_and_mic.c
@@ -30,8 +30,11 @@ PG_FUNCTION_INFO_V1(mic_to_latin4);
  *		INTEGER,	-- destination encoding id
  *		CSTRING,	-- source string (null terminated C string)
  *		CSTRING,	-- destination string (null terminated C string)
- *		INTEGER		-- source string length
- * ) returns VOID;
+ *		INTEGER,	-- source string length
+ *		BOOL		-- if true, don't throw an error if conversion fails
+ * ) returns INTEGER;
+ *
+ * Returns the number of bytes successfully converted.
  * ----------
  */
 
@@ -42,12 +45,14 @@ latin1_to_mic(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_LATIN1, PG_MULE_INTERNAL);
 
-	latin2mic(src, dest, len, LC_ISO8859_1, PG_LATIN1);
+	converted = latin2mic(src, dest, len, LC_ISO8859_1, PG_LATIN1, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -56,12 +61,14 @@ mic_to_latin1(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_MULE_INTERNAL, PG_LATIN1);
 
-	mic2latin(src, dest, len, LC_ISO8859_1, PG_LATIN1);
+	converted = mic2latin(src, dest, len, LC_ISO8859_1, PG_LATIN1, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -70,12 +77,14 @@ latin3_to_mic(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_LATIN3, PG_MULE_INTERNAL);
 
-	latin2mic(src, dest, len, LC_ISO8859_3, PG_LATIN3);
+	converted = latin2mic(src, dest, len, LC_ISO8859_3, PG_LATIN3, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -84,12 +93,14 @@ mic_to_latin3(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_MULE_INTERNAL, PG_LATIN3);
 
-	mic2latin(src, dest, len, LC_ISO8859_3, PG_LATIN3);
+	converted = mic2latin(src, dest, len, LC_ISO8859_3, PG_LATIN3, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -98,12 +109,14 @@ latin4_to_mic(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_LATIN4, PG_MULE_INTERNAL);
 
-	latin2mic(src, dest, len, LC_ISO8859_4, PG_LATIN4);
+	converted = latin2mic(src, dest, len, LC_ISO8859_4, PG_LATIN4, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -112,10 +125,12 @@ mic_to_latin4(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_MULE_INTERNAL, PG_LATIN4);
 
-	mic2latin(src, dest, len, LC_ISO8859_4, PG_LATIN4);
+	converted = mic2latin(src, dest, len, LC_ISO8859_4, PG_LATIN4, noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_big5/utf8_and_big5.c b/src/backend/utils/mb/conversion_procs/utf8_and_big5/utf8_and_big5.c
index d6067cdc24e..3838b15cab9 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_big5/utf8_and_big5.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_big5/utf8_and_big5.c
@@ -28,8 +28,11 @@ PG_FUNCTION_INFO_V1(utf8_to_big5);
  *		INTEGER,	-- destination encoding id
  *		CSTRING,	-- source string (null terminated C string)
  *		CSTRING,	-- destination string (null terminated C string)
- *		INTEGER		-- source string length
- * ) returns VOID;
+ *		INTEGER,	-- source string length
+ *		BOOL		-- if true, don't throw an error if conversion fails
+ * ) returns INTEGER;
+ *
+ * Returns the number of bytes successfully converted.
  * ----------
  */
 Datum
@@ -38,16 +41,19 @@ big5_to_utf8(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_BIG5, PG_UTF8);
 
-	LocalToUtf(src, len, dest,
-			   &big5_to_unicode_tree,
-			   NULL, 0,
-			   NULL,
-			   PG_BIG5);
+	converted = LocalToUtf(src, len, dest,
+						   &big5_to_unicode_tree,
+						   NULL, 0,
+						   NULL,
+						   PG_BIG5,
+						   noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -56,14 +62,17 @@ utf8_to_big5(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_UTF8, PG_BIG5);
 
-	UtfToLocal(src, len, dest,
-			   &big5_from_unicode_tree,
-			   NULL, 0,
-			   NULL,
-			   PG_BIG5);
+	converted = UtfToLocal(src, len, dest,
+						   &big5_from_unicode_tree,
+						   NULL, 0,
+						   NULL,
+						   PG_BIG5,
+						   noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_cyrillic/utf8_and_cyrillic.c b/src/backend/utils/mb/conversion_procs/utf8_and_cyrillic/utf8_and_cyrillic.c
index ed90e8e682e..75719fe5f1b 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_cyrillic/utf8_and_cyrillic.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_cyrillic/utf8_and_cyrillic.c
@@ -33,8 +33,11 @@ PG_FUNCTION_INFO_V1(koi8u_to_utf8);
  *		INTEGER,	-- destination encoding id
  *		CSTRING,	-- source string (null terminated C string)
  *		CSTRING,	-- destination string (null terminated C string)
- *		INTEGER		-- source string length
- * ) returns VOID;
+ *		INTEGER,	-- source string length
+ *		BOOL		-- if true, don't throw an error if conversion fails
+ * ) returns INTEGER;
+ *
+ * Returns the number of bytes successfully converted.
  * ----------
  */
 
@@ -44,16 +47,19 @@ utf8_to_koi8r(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_UTF8, PG_KOI8R);
 
-	UtfToLocal(src, len, dest,
-			   &koi8r_from_unicode_tree,
-			   NULL, 0,
-			   NULL,
-			   PG_KOI8R);
+	converted = UtfToLocal(src, len, dest,
+						   &koi8r_from_unicode_tree,
+						   NULL, 0,
+						   NULL,
+						   PG_KOI8R,
+						   noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -62,16 +68,19 @@ koi8r_to_utf8(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_KOI8R, PG_UTF8);
 
-	LocalToUtf(src, len, dest,
-			   &koi8r_to_unicode_tree,
-			   NULL, 0,
-			   NULL,
-			   PG_KOI8R);
+	converted = LocalToUtf(src, len, dest,
+						   &koi8r_to_unicode_tree,
+						   NULL, 0,
+						   NULL,
+						   PG_KOI8R,
+						   noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -80,16 +89,19 @@ utf8_to_koi8u(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_UTF8, PG_KOI8U);
 
-	UtfToLocal(src, len, dest,
-			   &koi8u_from_unicode_tree,
-			   NULL, 0,
-			   NULL,
-			   PG_KOI8U);
+	converted = UtfToLocal(src, len, dest,
+						   &koi8u_from_unicode_tree,
+						   NULL, 0,
+						   NULL,
+						   PG_KOI8U,
+						   noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -98,14 +110,17 @@ koi8u_to_utf8(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_KOI8U, PG_UTF8);
 
-	LocalToUtf(src, len, dest,
-			   &koi8u_to_unicode_tree,
-			   NULL, 0,
-			   NULL,
-			   PG_KOI8U);
+	converted = LocalToUtf(src, len, dest,
+						   &koi8u_to_unicode_tree,
+						   NULL, 0,
+						   NULL,
+						   PG_KOI8U,
+						   noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_euc2004/utf8_and_euc2004.c b/src/backend/utils/mb/conversion_procs/utf8_and_euc2004/utf8_and_euc2004.c
index d699affce47..5391001951a 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_euc2004/utf8_and_euc2004.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_euc2004/utf8_and_euc2004.c
@@ -28,8 +28,11 @@ PG_FUNCTION_INFO_V1(utf8_to_euc_jis_2004);
  *		INTEGER,	-- destination encoding id
  *		CSTRING,	-- source string (null terminated C string)
  *		CSTRING,	-- destination string (null terminated C string)
- *		INTEGER		-- source string length
- * ) returns VOID;
+ *		INTEGER,	-- source string length
+ *		BOOL		-- if true, don't throw an error if conversion fails
+ * ) returns INTEGER;
+ *
+ * Returns the number of bytes successfully converted.
  * ----------
  */
 Datum
@@ -38,16 +41,19 @@ euc_jis_2004_to_utf8(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_EUC_JIS_2004, PG_UTF8);
 
-	LocalToUtf(src, len, dest,
-			   &euc_jis_2004_to_unicode_tree,
-			   LUmapEUC_JIS_2004_combined, lengthof(LUmapEUC_JIS_2004_combined),
-			   NULL,
-			   PG_EUC_JIS_2004);
+	converted = LocalToUtf(src, len, dest,
+						   &euc_jis_2004_to_unicode_tree,
+						   LUmapEUC_JIS_2004_combined, lengthof(LUmapEUC_JIS_2004_combined),
+						   NULL,
+						   PG_EUC_JIS_2004,
+						   noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -56,14 +62,17 @@ utf8_to_euc_jis_2004(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_UTF8, PG_EUC_JIS_2004);
 
-	UtfToLocal(src, len, dest,
-			   &euc_jis_2004_from_unicode_tree,
-			   ULmapEUC_JIS_2004_combined, lengthof(ULmapEUC_JIS_2004_combined),
-			   NULL,
-			   PG_EUC_JIS_2004);
+	converted = UtfToLocal(src, len, dest,
+						   &euc_jis_2004_from_unicode_tree,
+						   ULmapEUC_JIS_2004_combined, lengthof(ULmapEUC_JIS_2004_combined),
+						   NULL,
+						   PG_EUC_JIS_2004,
+						   noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_euc_cn/utf8_and_euc_cn.c b/src/backend/utils/mb/conversion_procs/utf8_and_euc_cn/utf8_and_euc_cn.c
index d7c0ba6a58b..c87d1bf2398 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_euc_cn/utf8_and_euc_cn.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_euc_cn/utf8_and_euc_cn.c
@@ -28,8 +28,11 @@ PG_FUNCTION_INFO_V1(utf8_to_euc_cn);
  *		INTEGER,	-- destination encoding id
  *		CSTRING,	-- source string (null terminated C string)
  *		CSTRING,	-- destination string (null terminated C string)
- *		INTEGER		-- source string length
- * ) returns VOID;
+ *		INTEGER,	-- source string length
+ *		BOOL		-- if true, don't throw an error if conversion fails
+ * ) returns INTEGER;
+ *
+ * Returns the number of bytes successfully converted.
  * ----------
  */
 Datum
@@ -38,16 +41,19 @@ euc_cn_to_utf8(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_EUC_CN, PG_UTF8);
 
-	LocalToUtf(src, len, dest,
-			   &euc_cn_to_unicode_tree,
-			   NULL, 0,
-			   NULL,
-			   PG_EUC_CN);
+	converted = LocalToUtf(src, len, dest,
+						   &euc_cn_to_unicode_tree,
+						   NULL, 0,
+						   NULL,
+						   PG_EUC_CN,
+						   noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -56,14 +62,17 @@ utf8_to_euc_cn(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_UTF8, PG_EUC_CN);
 
-	UtfToLocal(src, len, dest,
-			   &euc_cn_from_unicode_tree,
-			   NULL, 0,
-			   NULL,
-			   PG_EUC_CN);
+	converted = UtfToLocal(src, len, dest,
+						   &euc_cn_from_unicode_tree,
+						   NULL, 0,
+						   NULL,
+						   PG_EUC_CN,
+						   noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_euc_jp/utf8_and_euc_jp.c b/src/backend/utils/mb/conversion_procs/utf8_and_euc_jp/utf8_and_euc_jp.c
index 13a3a23e77b..6a55134db21 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_euc_jp/utf8_and_euc_jp.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_euc_jp/utf8_and_euc_jp.c
@@ -28,8 +28,11 @@ PG_FUNCTION_INFO_V1(utf8_to_euc_jp);
  *		INTEGER,	-- destination encoding id
  *		CSTRING,	-- source string (null terminated C string)
  *		CSTRING,	-- destination string (null terminated C string)
- *		INTEGER		-- source string length
- * ) returns VOID;
+ *		INTEGER,	-- source string length
+ *		BOOL		-- if true, don't throw an error if conversion fails
+ * ) returns INTEGER;
+ *
+ * Returns the number of bytes successfully converted.
  * ----------
  */
 Datum
@@ -38,16 +41,19 @@ euc_jp_to_utf8(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_EUC_JP, PG_UTF8);
 
-	LocalToUtf(src, len, dest,
-			   &euc_jp_to_unicode_tree,
-			   NULL, 0,
-			   NULL,
-			   PG_EUC_JP);
+	converted = LocalToUtf(src, len, dest,
+						   &euc_jp_to_unicode_tree,
+						   NULL, 0,
+						   NULL,
+						   PG_EUC_JP,
+						   noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -56,14 +62,17 @@ utf8_to_euc_jp(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_UTF8, PG_EUC_JP);
 
-	UtfToLocal(src, len, dest,
-			   &euc_jp_from_unicode_tree,
-			   NULL, 0,
-			   NULL,
-			   PG_EUC_JP);
+	converted = UtfToLocal(src, len, dest,
+						   &euc_jp_from_unicode_tree,
+						   NULL, 0,
+						   NULL,
+						   PG_EUC_JP,
+						   noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_euc_kr/utf8_and_euc_kr.c b/src/backend/utils/mb/conversion_procs/utf8_and_euc_kr/utf8_and_euc_kr.c
index 1bbb8aaef7b..fe1924e2fec 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_euc_kr/utf8_and_euc_kr.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_euc_kr/utf8_and_euc_kr.c
@@ -28,8 +28,11 @@ PG_FUNCTION_INFO_V1(utf8_to_euc_kr);
  *		INTEGER,	-- destination encoding id
  *		CSTRING,	-- source string (null terminated C string)
  *		CSTRING,	-- destination string (null terminated C string)
- *		INTEGER		-- source string length
- * ) returns VOID;
+ *		INTEGER,	-- source string length
+ *		BOOL		-- if true, don't throw an error if conversion fails
+ * ) returns INTEGER;
+ *
+ * Returns the number of bytes successfully converted.
  * ----------
  */
 Datum
@@ -38,16 +41,19 @@ euc_kr_to_utf8(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_EUC_KR, PG_UTF8);
 
-	LocalToUtf(src, len, dest,
-			   &euc_kr_to_unicode_tree,
-			   NULL, 0,
-			   NULL,
-			   PG_EUC_KR);
+	converted = LocalToUtf(src, len, dest,
+						   &euc_kr_to_unicode_tree,
+						   NULL, 0,
+						   NULL,
+						   PG_EUC_KR,
+						   noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -56,14 +62,17 @@ utf8_to_euc_kr(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_UTF8, PG_EUC_KR);
 
-	UtfToLocal(src, len, dest,
-			   &euc_kr_from_unicode_tree,
-			   NULL, 0,
-			   NULL,
-			   PG_EUC_KR);
+	converted = UtfToLocal(src, len, dest,
+						   &euc_kr_from_unicode_tree,
+						   NULL, 0,
+						   NULL,
+						   PG_EUC_KR,
+						   noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_euc_tw/utf8_and_euc_tw.c b/src/backend/utils/mb/conversion_procs/utf8_and_euc_tw/utf8_and_euc_tw.c
index 9830045dccd..68215659b57 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_euc_tw/utf8_and_euc_tw.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_euc_tw/utf8_and_euc_tw.c
@@ -28,8 +28,11 @@ PG_FUNCTION_INFO_V1(utf8_to_euc_tw);
  *		INTEGER,	-- destination encoding id
  *		CSTRING,	-- source string (null terminated C string)
  *		CSTRING,	-- destination string (null terminated C string)
- *		INTEGER		-- source string length
- * ) returns VOID;
+ *		INTEGER,	-- source string length
+ *		BOOL		-- if true, don't throw an error if conversion fails
+ * ) returns INTEGER;
+ *
+ * Returns the number of bytes successfully converted.
  * ----------
  */
 Datum
@@ -38,16 +41,19 @@ euc_tw_to_utf8(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_EUC_TW, PG_UTF8);
 
-	LocalToUtf(src, len, dest,
-			   &euc_tw_to_unicode_tree,
-			   NULL, 0,
-			   NULL,
-			   PG_EUC_TW);
+	converted = LocalToUtf(src, len, dest,
+						   &euc_tw_to_unicode_tree,
+						   NULL, 0,
+						   NULL,
+						   PG_EUC_TW,
+						   noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -56,14 +62,17 @@ utf8_to_euc_tw(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_UTF8, PG_EUC_TW);
 
-	UtfToLocal(src, len, dest,
-			   &euc_tw_from_unicode_tree,
-			   NULL, 0,
-			   NULL,
-			   PG_EUC_TW);
+	converted = UtfToLocal(src, len, dest,
+						   &euc_tw_from_unicode_tree,
+						   NULL, 0,
+						   NULL,
+						   PG_EUC_TW,
+						   noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_gb18030/utf8_and_gb18030.c b/src/backend/utils/mb/conversion_procs/utf8_and_gb18030/utf8_and_gb18030.c
index f86ecf27424..e1a59c39a4d 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_gb18030/utf8_and_gb18030.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_gb18030/utf8_and_gb18030.c
@@ -183,8 +183,11 @@ conv_utf8_to_18030(uint32 code)
  *		INTEGER,	-- destination encoding id
  *		CSTRING,	-- source string (null terminated C string)
  *		CSTRING,	-- destination string (null terminated C string)
- *		INTEGER		-- source string length
- * ) returns VOID;
+ *		INTEGER,	-- source string length
+ *		BOOL		-- if true, don't throw an error if conversion fails
+ * ) returns INTEGER;
+ *
+ * Returns the number of bytes successfully converted.
  * ----------
  */
 Datum
@@ -193,16 +196,19 @@ gb18030_to_utf8(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_GB18030, PG_UTF8);
 
-	LocalToUtf(src, len, dest,
-			   &gb18030_to_unicode_tree,
-			   NULL, 0,
-			   conv_18030_to_utf8,
-			   PG_GB18030);
+	converted = LocalToUtf(src, len, dest,
+						   &gb18030_to_unicode_tree,
+						   NULL, 0,
+						   conv_18030_to_utf8,
+						   PG_GB18030,
+						   noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -211,14 +217,17 @@ utf8_to_gb18030(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_UTF8, PG_GB18030);
 
-	UtfToLocal(src, len, dest,
-			   &gb18030_from_unicode_tree,
-			   NULL, 0,
-			   conv_utf8_to_18030,
-			   PG_GB18030);
+	converted = UtfToLocal(src, len, dest,
+						   &gb18030_from_unicode_tree,
+						   NULL, 0,
+						   conv_utf8_to_18030,
+						   PG_GB18030,
+						   noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_gbk/utf8_and_gbk.c b/src/backend/utils/mb/conversion_procs/utf8_and_gbk/utf8_and_gbk.c
index 2ab8b16c8a8..881386d5347 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_gbk/utf8_and_gbk.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_gbk/utf8_and_gbk.c
@@ -28,8 +28,11 @@ PG_FUNCTION_INFO_V1(utf8_to_gbk);
  *		INTEGER,	-- destination encoding id
  *		CSTRING,	-- source string (null terminated C string)
  *		CSTRING,	-- destination string (null terminated C string)
- *		INTEGER		-- source string length
- * ) returns VOID;
+ *		INTEGER,	-- source string length
+ *		BOOL		-- if true, don't throw an error if conversion fails
+ * ) returns INTEGER;
+ *
+ * Returns the number of bytes successfully converted.
  * ----------
  */
 Datum
@@ -38,16 +41,19 @@ gbk_to_utf8(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_GBK, PG_UTF8);
 
-	LocalToUtf(src, len, dest,
-			   &gbk_to_unicode_tree,
-			   NULL, 0,
-			   NULL,
-			   PG_GBK);
+	converted = LocalToUtf(src, len, dest,
+						   &gbk_to_unicode_tree,
+						   NULL, 0,
+						   NULL,
+						   PG_GBK,
+						   noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -56,14 +62,17 @@ utf8_to_gbk(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_UTF8, PG_GBK);
 
-	UtfToLocal(src, len, dest,
-			   &gbk_from_unicode_tree,
-			   NULL, 0,
-			   NULL,
-			   PG_GBK);
+	converted = UtfToLocal(src, len, dest,
+						   &gbk_from_unicode_tree,
+						   NULL, 0,
+						   NULL,
+						   PG_GBK,
+						   noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_iso8859/utf8_and_iso8859.c b/src/backend/utils/mb/conversion_procs/utf8_and_iso8859/utf8_and_iso8859.c
index 3e49f67ea2f..d93a521badf 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_iso8859/utf8_and_iso8859.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_iso8859/utf8_and_iso8859.c
@@ -52,8 +52,11 @@ PG_FUNCTION_INFO_V1(utf8_to_iso8859);
  *		INTEGER,	-- destination encoding id
  *		CSTRING,	-- source string (null terminated C string)
  *		CSTRING,	-- destination string (null terminated C string)
- *		INTEGER		-- source string length
- * ) returns VOID;
+ *		INTEGER,	-- source string length
+ *		BOOL		-- if true, don't throw an error if conversion fails
+ * ) returns INTEGER;
+ *
+ * Returns the number of bytes successfully converted.
  * ----------
  */
 
@@ -100,6 +103,7 @@ iso8859_to_utf8(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
 	int			i;
 
 	CHECK_ENCODING_CONVERSION_ARGS(-1, PG_UTF8);
@@ -108,12 +112,15 @@ iso8859_to_utf8(PG_FUNCTION_ARGS)
 	{
 		if (encoding == maps[i].encoding)
 		{
-			LocalToUtf(src, len, dest,
-					   maps[i].map1,
-					   NULL, 0,
-					   NULL,
-					   encoding);
-			PG_RETURN_VOID();
+			int			converted;
+
+			converted = LocalToUtf(src, len, dest,
+								   maps[i].map1,
+								   NULL, 0,
+								   NULL,
+								   encoding,
+								   noError);
+			PG_RETURN_INT32(converted);
 		}
 	}
 
@@ -122,7 +129,7 @@ iso8859_to_utf8(PG_FUNCTION_ARGS)
 			 errmsg("unexpected encoding ID %d for ISO 8859 character sets",
 					encoding)));
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(0);
 }
 
 Datum
@@ -132,6 +139,7 @@ utf8_to_iso8859(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
 	int			i;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_UTF8, -1);
@@ -140,12 +148,15 @@ utf8_to_iso8859(PG_FUNCTION_ARGS)
 	{
 		if (encoding == maps[i].encoding)
 		{
-			UtfToLocal(src, len, dest,
-					   maps[i].map2,
-					   NULL, 0,
-					   NULL,
-					   encoding);
-			PG_RETURN_VOID();
+			int			converted;
+
+			converted = UtfToLocal(src, len, dest,
+								   maps[i].map2,
+								   NULL, 0,
+								   NULL,
+								   encoding,
+								   noError);
+			PG_RETURN_INT32(converted);
 		}
 	}
 
@@ -154,5 +165,5 @@ utf8_to_iso8859(PG_FUNCTION_ARGS)
 			 errmsg("unexpected encoding ID %d for ISO 8859 character sets",
 					encoding)));
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(0);
 }
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_iso8859_1/utf8_and_iso8859_1.c b/src/backend/utils/mb/conversion_procs/utf8_and_iso8859_1/utf8_and_iso8859_1.c
index 67e713cca11..d0dc4cca378 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_iso8859_1/utf8_and_iso8859_1.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_iso8859_1/utf8_and_iso8859_1.c
@@ -26,8 +26,11 @@ PG_FUNCTION_INFO_V1(utf8_to_iso8859_1);
  *		INTEGER,	-- destination encoding id
  *		CSTRING,	-- source string (null terminated C string)
  *		CSTRING,	-- destination string (null terminated C string)
- *		INTEGER		-- source string length
- * ) returns VOID;
+ *		INTEGER,	-- source string length
+ *		BOOL		-- if true, don't throw an error if conversion fails
+ * ) returns INTEGER;
+ *
+ * Returns the number of bytes successfully converted.
  * ----------
  */
 
@@ -37,6 +40,8 @@ iso8859_1_to_utf8(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	unsigned char *start = src;
 	unsigned short c;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_LATIN1, PG_UTF8);
@@ -45,7 +50,11 @@ iso8859_1_to_utf8(PG_FUNCTION_ARGS)
 	{
 		c = *src;
 		if (c == 0)
+		{
+			if (noError)
+				break;
 			report_invalid_encoding(PG_LATIN1, (const char *) src, len);
+		}
 		if (!IS_HIGHBIT_SET(c))
 			*dest++ = c;
 		else
@@ -58,7 +67,7 @@ iso8859_1_to_utf8(PG_FUNCTION_ARGS)
 	}
 	*dest = '\0';
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(src - start);
 }
 
 Datum
@@ -67,6 +76,8 @@ utf8_to_iso8859_1(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	unsigned char *start = src;
 	unsigned short c,
 				c1;
 
@@ -76,7 +87,11 @@ utf8_to_iso8859_1(PG_FUNCTION_ARGS)
 	{
 		c = *src;
 		if (c == 0)
+		{
+			if (noError)
+				break;
 			report_invalid_encoding(PG_UTF8, (const char *) src, len);
+		}
 		/* fast path for ASCII-subset characters */
 		if (!IS_HIGHBIT_SET(c))
 		{
@@ -89,10 +104,18 @@ utf8_to_iso8859_1(PG_FUNCTION_ARGS)
 			int			l = pg_utf_mblen(src);
 
 			if (l > len || !pg_utf8_islegal(src, l))
+			{
+				if (noError)
+					break;
 				report_invalid_encoding(PG_UTF8, (const char *) src, len);
+			}
 			if (l != 2)
+			{
+				if (noError)
+					break;
 				report_untranslatable_char(PG_UTF8, PG_LATIN1,
 										   (const char *) src, len);
+			}
 			c1 = src[1] & 0x3f;
 			c = ((c & 0x1f) << 6) | c1;
 			if (c >= 0x80 && c <= 0xff)
@@ -102,11 +125,15 @@ utf8_to_iso8859_1(PG_FUNCTION_ARGS)
 				len -= 2;
 			}
 			else
+			{
+				if (noError)
+					break;
 				report_untranslatable_char(PG_UTF8, PG_LATIN1,
 										   (const char *) src, len);
+			}
 		}
 	}
 	*dest = '\0';
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(src - start);
 }
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_johab/utf8_and_johab.c b/src/backend/utils/mb/conversion_procs/utf8_and_johab/utf8_and_johab.c
index 578f5df4e7f..317daa2d5ee 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_johab/utf8_and_johab.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_johab/utf8_and_johab.c
@@ -28,8 +28,11 @@ PG_FUNCTION_INFO_V1(utf8_to_johab);
  *		INTEGER,	-- destination encoding id
  *		CSTRING,	-- source string (null terminated C string)
  *		CSTRING,	-- destination string (null terminated C string)
- *		INTEGER		-- source string length
- * ) returns VOID;
+ *		INTEGER,	-- source string length
+ *		BOOL		-- if true, don't throw an error if conversion fails
+ * ) returns INTEGER;
+ *
+ * Returns the number of bytes successfully converted.
  * ----------
  */
 Datum
@@ -38,16 +41,19 @@ johab_to_utf8(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_JOHAB, PG_UTF8);
 
-	LocalToUtf(src, len, dest,
-			   &johab_to_unicode_tree,
-			   NULL, 0,
-			   NULL,
-			   PG_JOHAB);
+	converted = LocalToUtf(src, len, dest,
+						   &johab_to_unicode_tree,
+						   NULL, 0,
+						   NULL,
+						   PG_JOHAB,
+						   noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -56,14 +62,17 @@ utf8_to_johab(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_UTF8, PG_JOHAB);
 
-	UtfToLocal(src, len, dest,
-			   &johab_from_unicode_tree,
-			   NULL, 0,
-			   NULL,
-			   PG_JOHAB);
+	converted = UtfToLocal(src, len, dest,
+						   &johab_from_unicode_tree,
+						   NULL, 0,
+						   NULL,
+						   PG_JOHAB,
+						   noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_sjis/utf8_and_sjis.c b/src/backend/utils/mb/conversion_procs/utf8_and_sjis/utf8_and_sjis.c
index dd9fc2975ad..4c9348aba59 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_sjis/utf8_and_sjis.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_sjis/utf8_and_sjis.c
@@ -28,8 +28,11 @@ PG_FUNCTION_INFO_V1(utf8_to_sjis);
  *		INTEGER,	-- destination encoding id
  *		CSTRING,	-- source string (null terminated C string)
  *		CSTRING,	-- destination string (null terminated C string)
- *		INTEGER		-- source string length
- * ) returns VOID;
+ *		INTEGER,	-- source string length
+ *		BOOL		-- if true, don't throw an error if conversion fails
+ * ) returns INTEGER;
+ *
+ * Returns the number of bytes successfully converted.
  * ----------
  */
 Datum
@@ -38,16 +41,19 @@ sjis_to_utf8(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_SJIS, PG_UTF8);
 
-	LocalToUtf(src, len, dest,
-			   &sjis_to_unicode_tree,
-			   NULL, 0,
-			   NULL,
-			   PG_SJIS);
+	converted = LocalToUtf(src, len, dest,
+						   &sjis_to_unicode_tree,
+						   NULL, 0,
+						   NULL,
+						   PG_SJIS,
+						   noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -56,14 +62,17 @@ utf8_to_sjis(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_UTF8, PG_SJIS);
 
-	UtfToLocal(src, len, dest,
-			   &sjis_from_unicode_tree,
-			   NULL, 0,
-			   NULL,
-			   PG_SJIS);
+	converted = UtfToLocal(src, len, dest,
+						   &sjis_from_unicode_tree,
+						   NULL, 0,
+						   NULL,
+						   PG_SJIS,
+						   noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_sjis2004/utf8_and_sjis2004.c b/src/backend/utils/mb/conversion_procs/utf8_and_sjis2004/utf8_and_sjis2004.c
index 4bcc886d674..1fffdc5930c 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_sjis2004/utf8_and_sjis2004.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_sjis2004/utf8_and_sjis2004.c
@@ -28,8 +28,11 @@ PG_FUNCTION_INFO_V1(utf8_to_shift_jis_2004);
  *		INTEGER,	-- destination encoding id
  *		CSTRING,	-- source string (null terminated C string)
  *		CSTRING,	-- destination string (null terminated C string)
- *		INTEGER		-- source string length
- * ) returns VOID;
+ *		INTEGER,	-- source string length
+ *		BOOL		-- if true, don't throw an error if conversion fails
+ * ) returns INTEGER;
+ *
+ * Returns the number of bytes successfully converted.
  * ----------
  */
 Datum
@@ -38,16 +41,19 @@ shift_jis_2004_to_utf8(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_SHIFT_JIS_2004, PG_UTF8);
 
-	LocalToUtf(src, len, dest,
-			   &shift_jis_2004_to_unicode_tree,
-			   LUmapSHIFT_JIS_2004_combined, lengthof(LUmapSHIFT_JIS_2004_combined),
-			   NULL,
-			   PG_SHIFT_JIS_2004);
+	converted = LocalToUtf(src, len, dest,
+						   &shift_jis_2004_to_unicode_tree,
+						   LUmapSHIFT_JIS_2004_combined, lengthof(LUmapSHIFT_JIS_2004_combined),
+						   NULL,
+						   PG_SHIFT_JIS_2004,
+						   noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -56,14 +62,17 @@ utf8_to_shift_jis_2004(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_UTF8, PG_SHIFT_JIS_2004);
 
-	UtfToLocal(src, len, dest,
-			   &shift_jis_2004_from_unicode_tree,
-			   ULmapSHIFT_JIS_2004_combined, lengthof(ULmapSHIFT_JIS_2004_combined),
-			   NULL,
-			   PG_SHIFT_JIS_2004);
+	converted = UtfToLocal(src, len, dest,
+						   &shift_jis_2004_from_unicode_tree,
+						   ULmapSHIFT_JIS_2004_combined, lengthof(ULmapSHIFT_JIS_2004_combined),
+						   NULL,
+						   PG_SHIFT_JIS_2004,
+						   noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_uhc/utf8_and_uhc.c b/src/backend/utils/mb/conversion_procs/utf8_and_uhc/utf8_and_uhc.c
index c8e512994a1..d9471dad097 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_uhc/utf8_and_uhc.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_uhc/utf8_and_uhc.c
@@ -28,8 +28,11 @@ PG_FUNCTION_INFO_V1(utf8_to_uhc);
  *		INTEGER,	-- destination encoding id
  *		CSTRING,	-- source string (null terminated C string)
  *		CSTRING,	-- destination string (null terminated C string)
- *		INTEGER		-- source string length
- * ) returns VOID;
+ *		INTEGER,	-- source string length
+ *		BOOL		-- if true, don't throw an error if conversion fails
+ * ) returns INTEGER;
+ *
+ * Returns the number of bytes successfully converted.
  * ----------
  */
 Datum
@@ -38,16 +41,19 @@ uhc_to_utf8(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_UHC, PG_UTF8);
 
-	LocalToUtf(src, len, dest,
-			   &uhc_to_unicode_tree,
-			   NULL, 0,
-			   NULL,
-			   PG_UHC);
+	converted = LocalToUtf(src, len, dest,
+						   &uhc_to_unicode_tree,
+						   NULL, 0,
+						   NULL,
+						   PG_UHC,
+						   noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
 
 Datum
@@ -56,14 +62,17 @@ utf8_to_uhc(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
+	int			converted;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_UTF8, PG_UHC);
 
-	UtfToLocal(src, len, dest,
-			   &uhc_from_unicode_tree,
-			   NULL, 0,
-			   NULL,
-			   PG_UHC);
+	converted = UtfToLocal(src, len, dest,
+						   &uhc_from_unicode_tree,
+						   NULL, 0,
+						   NULL,
+						   PG_UHC,
+						   noError);
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(converted);
 }
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_win/utf8_and_win.c b/src/backend/utils/mb/conversion_procs/utf8_and_win/utf8_and_win.c
index 0c9493dee56..110ba5677d0 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_win/utf8_and_win.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_win/utf8_and_win.c
@@ -48,8 +48,11 @@ PG_FUNCTION_INFO_V1(utf8_to_win);
  *		INTEGER,	-- destination encoding id
  *		CSTRING,	-- source string (null terminated C string)
  *		CSTRING,	-- destination string (null terminated C string)
- *		INTEGER		-- source string length
- * ) returns VOID;
+ *		INTEGER,	-- source string length
+ *		BOOL		-- if true, don't throw an error if conversion fails
+ * ) returns INTEGER;
+ *
+ * Returns the number of bytes successfully converted.
  * ----------
  */
 
@@ -81,6 +84,7 @@ win_to_utf8(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
 	int			i;
 
 	CHECK_ENCODING_CONVERSION_ARGS(-1, PG_UTF8);
@@ -89,12 +93,15 @@ win_to_utf8(PG_FUNCTION_ARGS)
 	{
 		if (encoding == maps[i].encoding)
 		{
-			LocalToUtf(src, len, dest,
-					   maps[i].map1,
-					   NULL, 0,
-					   NULL,
-					   encoding);
-			PG_RETURN_VOID();
+			int			converted;
+
+			converted = LocalToUtf(src, len, dest,
+								   maps[i].map1,
+								   NULL, 0,
+								   NULL,
+								   encoding,
+								   noError);
+			PG_RETURN_INT32(converted);
 		}
 	}
 
@@ -103,7 +110,7 @@ win_to_utf8(PG_FUNCTION_ARGS)
 			 errmsg("unexpected encoding ID %d for WIN character sets",
 					encoding)));
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(0);
 }
 
 Datum
@@ -113,6 +120,7 @@ utf8_to_win(PG_FUNCTION_ARGS)
 	unsigned char *src = (unsigned char *) PG_GETARG_CSTRING(2);
 	unsigned char *dest = (unsigned char *) PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
+	bool		noError = PG_GETARG_BOOL(5);
 	int			i;
 
 	CHECK_ENCODING_CONVERSION_ARGS(PG_UTF8, -1);
@@ -121,12 +129,15 @@ utf8_to_win(PG_FUNCTION_ARGS)
 	{
 		if (encoding == maps[i].encoding)
 		{
-			UtfToLocal(src, len, dest,
-					   maps[i].map2,
-					   NULL, 0,
-					   NULL,
-					   encoding);
-			PG_RETURN_VOID();
+			int			converted;
+
+			converted = UtfToLocal(src, len, dest,
+								   maps[i].map2,
+								   NULL, 0,
+								   NULL,
+								   encoding,
+								   noError);
+			PG_RETURN_INT32(converted);
 		}
 	}
 
@@ -135,5 +146,5 @@ utf8_to_win(PG_FUNCTION_ARGS)
 			 errmsg("unexpected encoding ID %d for WIN character sets",
 					encoding)));
 
-	PG_RETURN_VOID();
+	PG_RETURN_INT32(0);
 }
diff --git a/src/backend/utils/mb/mbutils.c b/src/backend/utils/mb/mbutils.c
index 2578573b0ab..a13c398f4ac 100644
--- a/src/backend/utils/mb/mbutils.c
+++ b/src/backend/utils/mb/mbutils.c
@@ -406,12 +406,13 @@ pg_do_encoding_conversion(unsigned char *src, int len,
 		MemoryContextAllocHuge(CurrentMemoryContext,
 							   (Size) len * MAX_CONVERSION_GROWTH + 1);
 
-	OidFunctionCall5(proc,
-					 Int32GetDatum(src_encoding),
-					 Int32GetDatum(dest_encoding),
-					 CStringGetDatum(src),
-					 CStringGetDatum(result),
-					 Int32GetDatum(len));
+	(void) OidFunctionCall6(proc,
+							Int32GetDatum(src_encoding),
+							Int32GetDatum(dest_encoding),
+							CStringGetDatum(src),
+							CStringGetDatum(result),
+							Int32GetDatum(len),
+							BoolGetDatum(false));
 
 	/*
 	 * If the result is large, it's worth repalloc'ing to release any extra
@@ -435,6 +436,62 @@ pg_do_encoding_conversion(unsigned char *src, int len,
 	return result;
 }
 
+/*
+ * Convert src string to another encoding.
+ *
+ * This function has a different API than the other conversion functions.
+ * The caller should've looked up the conversion function using
+ * FindDefaultConversionProc().  Unlike the other functions, the converted
+ * result is not palloc'd.  It is written to the caller-supplied buffer
+ * instead.
+ *
+ * src_encoding   - encoding to convert from
+ * dest_encoding  - encoding to convert to
+ * src, srclen    - input buffer and its length in bytes
+ * dest, destlen  - destination buffer and its size in bytes
+ *
+ * The output is null-terminated.
+ *
+ * If destlen < srclen * MAX_CONVERSION_LENGTH + 1, the converted output
+ * wouldn't necessarily fit in the output buffer, and the function will not
+ * convert the whole input.
+ *
+ * TODO: The conversion function interface is not great.  Firstly, it
+ * would be nice to pass through the destination buffer size to the
+ * conversion function, so that if you pass a shorter destination buffer, it
+ * could still continue to fill up the whole buffer.  Currently, we have to
+ * assume worst case expansion and stop the conversion short, even if there
+ * is in fact space left in the destination buffer.  Secondly, it would be
+ * nice to return the number of bytes written to the caller, to avoid a call
+ * to strlen().
+ */
+int
+pg_do_encoding_conversion_buf(Oid proc,
+							  int src_encoding,
+							  int dest_encoding,
+							  unsigned char *src, int srclen,
+							  unsigned char *dest, int destlen,
+							  bool noError)
+{
+	Datum		result;
+
+	/*
+	 * If the destination buffer is not large enough to hold the result in the
+	 * worst case, limit the input size passed to the conversion function.
+	 */
+	if ((Size) srclen >= ((destlen - 1) / (Size) MAX_CONVERSION_GROWTH))
+		srclen = ((destlen - 1) / (Size) MAX_CONVERSION_GROWTH);
+
+	result = OidFunctionCall6(proc,
+							  Int32GetDatum(src_encoding),
+							  Int32GetDatum(dest_encoding),
+							  CStringGetDatum(src),
+							  CStringGetDatum(dest),
+							  Int32GetDatum(srclen),
+							  BoolGetDatum(noError));
+	return DatumGetInt32(result);
+}
+
 /*
  * Convert string to encoding encoding_name. The source
  * encoding is the DB encoding.
@@ -762,12 +819,13 @@ perform_default_encoding_conversion(const char *src, int len,
 		MemoryContextAllocHuge(CurrentMemoryContext,
 							   (Size) len * MAX_CONVERSION_GROWTH + 1);
 
-	FunctionCall5(flinfo,
+	FunctionCall6(flinfo,
 				  Int32GetDatum(src_encoding),
 				  Int32GetDatum(dest_encoding),
 				  CStringGetDatum(src),
 				  CStringGetDatum(result),
-				  Int32GetDatum(len));
+				  Int32GetDatum(len),
+				  BoolGetDatum(false));
 
 	/*
 	 * Release extra space if there might be a lot --- see comments in
@@ -849,12 +907,13 @@ pg_unicode_to_server(pg_wchar c, unsigned char *s)
 	c_as_utf8[c_as_utf8_len] = '\0';
 
 	/* Convert, or throw error if we can't */
-	FunctionCall5(Utf8ToServerConvProc,
+	FunctionCall6(Utf8ToServerConvProc,
 				  Int32GetDatum(PG_UTF8),
 				  Int32GetDatum(server_encoding),
 				  CStringGetDatum(c_as_utf8),
 				  CStringGetDatum(s),
-				  Int32GetDatum(c_as_utf8_len));
+				  Int32GetDatum(c_as_utf8_len),
+				  BoolGetDatum(false));
 }
 
 
diff --git a/src/bin/pg_upgrade/check.c b/src/bin/pg_upgrade/check.c
index 43fc297eb69..d77183b8d12 100644
--- a/src/bin/pg_upgrade/check.c
+++ b/src/bin/pg_upgrade/check.c
@@ -28,6 +28,7 @@ static void check_for_reg_data_type_usage(ClusterInfo *cluster);
 static void check_for_jsonb_9_4_usage(ClusterInfo *cluster);
 static void check_for_pg_role_prefix(ClusterInfo *cluster);
 static void check_for_new_tablespace_dir(ClusterInfo *new_cluster);
+static void check_for_user_defined_encoding_conversions(ClusterInfo *cluster);
 static char *get_canonical_locale_name(int category, const char *locale);
 
 
@@ -102,6 +103,15 @@ check_and_dump_old_cluster(bool live_check)
 	check_for_reg_data_type_usage(&old_cluster);
 	check_for_isn_and_int8_passing_mismatch(&old_cluster);
 
+	/*
+	 * PG 14 changed the function signature of encoding conversion functions.
+	 * Conversions from older versions cannot be upgraded automatically
+	 * because the user-defined functions used by the encoding conversions
+	 * need to be changed to match the new signature.
+	 */
+	if (GET_MAJOR_VERSION(old_cluster.major_version) <= 1300)
+		check_for_user_defined_encoding_conversions(&old_cluster);
+
 	/*
 	 * Pre-PG 14 allowed user defined postfix operators, which are not
 	 * supported anymore.  Verify there are none, iff applicable.
@@ -1268,6 +1278,91 @@ check_for_pg_role_prefix(ClusterInfo *cluster)
 	check_ok();
 }
 
+/*
+ * Verify that no user-defined encoding conversions exist.
+ */
+static void
+check_for_user_defined_encoding_conversions(ClusterInfo *cluster)
+{
+	int			dbnum;
+	FILE	   *script = NULL;
+	bool		found = false;
+	char		output_path[MAXPGPATH];
+
+	prep_status("Checking for user-defined encoding conversions");
+
+	snprintf(output_path, sizeof(output_path),
+			 "encoding_conversions.txt");
+
+	/* Find any user defined encoding conversions */
+	for (dbnum = 0; dbnum < cluster->dbarr.ndbs; dbnum++)
+	{
+		PGresult   *res;
+		bool		db_used = false;
+		int			ntups;
+		int			rowno;
+		int			i_conoid,
+					i_conname,
+					i_nspname;
+		DbInfo	   *active_db = &cluster->dbarr.dbs[dbnum];
+		PGconn	   *conn = connectToServer(cluster, active_db->db_name);
+
+		/*
+		 * The query below hardcodes FirstNormalObjectId as 16384 rather than
+		 * interpolating that C #define into the query because, if that
+		 * #define is ever changed, the cutoff we want to use is the value
+		 * used by pre-version 14 servers, not that of some future version.
+		 */
+		res = executeQueryOrDie(conn,
+								"SELECT c.oid as conoid, c.conname, n.nspname "
+								"FROM pg_catalog.pg_conversion c, "
+								"     pg_catalog.pg_namespace n "
+								"WHERE c.connamespace = n.oid AND "
+								"      c.oid >= 16384");
+		ntups = PQntuples(res);
+		i_conoid = PQfnumber(res, "conoid");
+		i_conname = PQfnumber(res, "conname");
+		i_nspname = PQfnumber(res, "nspname");
+		for (rowno = 0; rowno < ntups; rowno++)
+		{
+			found = true;
+			if (script == NULL &&
+				(script = fopen_priv(output_path, "w")) == NULL)
+				pg_fatal("could not open file \"%s\": %s\n",
+						 output_path, strerror(errno));
+			if (!db_used)
+			{
+				fprintf(script, "In database: %s\n", active_db->db_name);
+				db_used = true;
+			}
+			fprintf(script, "  (oid=%s) %s.%s\n",
+					PQgetvalue(res, rowno, i_conoid),
+					PQgetvalue(res, rowno, i_nspname),
+					PQgetvalue(res, rowno, i_conname));
+		}
+
+		PQclear(res);
+
+		PQfinish(conn);
+	}
+
+	if (script)
+		fclose(script);
+
+	if (found)
+	{
+		pg_log(PG_REPORT, "fatal\n");
+		pg_fatal("Your installation contains user-defined encoding conversions.\n"
+				 "The conversion function parameters changed in PostgreSQL version 14\n"
+				 "so this cluster cannot currently be upgraded.  You can remove the\n"
+				 "encoding conversions in the old cluster and restart the upgrade.\n"
+				 "A list of user-defined encoding conversions is in the file:\n"
+				 "    %s\n\n", output_path);
+	}
+	else
+		check_ok();
+}
+
 
 /*
  * get_canonical_locale_name
diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h
index 489f5be427f..6a61c8f64f0 100644
--- a/src/include/catalog/catversion.h
+++ b/src/include/catalog/catversion.h
@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	202103291
+#define CATALOG_VERSION_NO	202104011
 
 #endif
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index bfb89e0575d..69ffd0c3f4d 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -10914,388 +10914,388 @@
 # conversion functions
 { oid => '4302',
   descr => 'internal conversion function for KOI8R to MULE_INTERNAL',
-  proname => 'koi8r_to_mic', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'koi8r_to_mic',
+  proname => 'koi8r_to_mic', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'koi8r_to_mic',
   probin => '$libdir/cyrillic_and_mic' },
 { oid => '4303',
   descr => 'internal conversion function for MULE_INTERNAL to KOI8R',
-  proname => 'mic_to_koi8r', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'mic_to_koi8r',
+  proname => 'mic_to_koi8r', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'mic_to_koi8r',
   probin => '$libdir/cyrillic_and_mic' },
 { oid => '4304',
   descr => 'internal conversion function for ISO-8859-5 to MULE_INTERNAL',
-  proname => 'iso_to_mic', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'iso_to_mic',
+  proname => 'iso_to_mic', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'iso_to_mic',
   probin => '$libdir/cyrillic_and_mic' },
 { oid => '4305',
   descr => 'internal conversion function for MULE_INTERNAL to ISO-8859-5',
-  proname => 'mic_to_iso', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'mic_to_iso',
+  proname => 'mic_to_iso', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'mic_to_iso',
   probin => '$libdir/cyrillic_and_mic' },
 { oid => '4306',
   descr => 'internal conversion function for WIN1251 to MULE_INTERNAL',
-  proname => 'win1251_to_mic', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'win1251_to_mic',
+  proname => 'win1251_to_mic', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'win1251_to_mic',
   probin => '$libdir/cyrillic_and_mic' },
 { oid => '4307',
   descr => 'internal conversion function for MULE_INTERNAL to WIN1251',
-  proname => 'mic_to_win1251', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'mic_to_win1251',
+  proname => 'mic_to_win1251', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'mic_to_win1251',
   probin => '$libdir/cyrillic_and_mic' },
 { oid => '4308',
   descr => 'internal conversion function for WIN866 to MULE_INTERNAL',
-  proname => 'win866_to_mic', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'win866_to_mic',
+  proname => 'win866_to_mic', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'win866_to_mic',
   probin => '$libdir/cyrillic_and_mic' },
 { oid => '4309',
   descr => 'internal conversion function for MULE_INTERNAL to WIN866',
-  proname => 'mic_to_win866', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'mic_to_win866',
+  proname => 'mic_to_win866', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'mic_to_win866',
   probin => '$libdir/cyrillic_and_mic' },
 { oid => '4310', descr => 'internal conversion function for KOI8R to WIN1251',
-  proname => 'koi8r_to_win1251', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4',
+  proname => 'koi8r_to_win1251', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool',
   prosrc => 'koi8r_to_win1251', probin => '$libdir/cyrillic_and_mic' },
 { oid => '4311', descr => 'internal conversion function for WIN1251 to KOI8R',
-  proname => 'win1251_to_koi8r', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4',
+  proname => 'win1251_to_koi8r', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool',
   prosrc => 'win1251_to_koi8r', probin => '$libdir/cyrillic_and_mic' },
 { oid => '4312', descr => 'internal conversion function for KOI8R to WIN866',
-  proname => 'koi8r_to_win866', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'koi8r_to_win866',
+  proname => 'koi8r_to_win866', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'koi8r_to_win866',
   probin => '$libdir/cyrillic_and_mic' },
 { oid => '4313', descr => 'internal conversion function for WIN866 to KOI8R',
-  proname => 'win866_to_koi8r', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'win866_to_koi8r',
+  proname => 'win866_to_koi8r', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'win866_to_koi8r',
   probin => '$libdir/cyrillic_and_mic' },
 { oid => '4314',
   descr => 'internal conversion function for WIN866 to WIN1251',
-  proname => 'win866_to_win1251', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4',
+  proname => 'win866_to_win1251', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool',
   prosrc => 'win866_to_win1251', probin => '$libdir/cyrillic_and_mic' },
 { oid => '4315',
   descr => 'internal conversion function for WIN1251 to WIN866',
-  proname => 'win1251_to_win866', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4',
+  proname => 'win1251_to_win866', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool',
   prosrc => 'win1251_to_win866', probin => '$libdir/cyrillic_and_mic' },
 { oid => '4316',
   descr => 'internal conversion function for ISO-8859-5 to KOI8R',
-  proname => 'iso_to_koi8r', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'iso_to_koi8r',
+  proname => 'iso_to_koi8r', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'iso_to_koi8r',
   probin => '$libdir/cyrillic_and_mic' },
 { oid => '4317',
   descr => 'internal conversion function for KOI8R to ISO-8859-5',
-  proname => 'koi8r_to_iso', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'koi8r_to_iso',
+  proname => 'koi8r_to_iso', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'koi8r_to_iso',
   probin => '$libdir/cyrillic_and_mic' },
 { oid => '4318',
   descr => 'internal conversion function for ISO-8859-5 to WIN1251',
-  proname => 'iso_to_win1251', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'iso_to_win1251',
+  proname => 'iso_to_win1251', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'iso_to_win1251',
   probin => '$libdir/cyrillic_and_mic' },
 { oid => '4319',
   descr => 'internal conversion function for WIN1251 to ISO-8859-5',
-  proname => 'win1251_to_iso', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'win1251_to_iso',
+  proname => 'win1251_to_iso', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'win1251_to_iso',
   probin => '$libdir/cyrillic_and_mic' },
 { oid => '4320',
   descr => 'internal conversion function for ISO-8859-5 to WIN866',
-  proname => 'iso_to_win866', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'iso_to_win866',
+  proname => 'iso_to_win866', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'iso_to_win866',
   probin => '$libdir/cyrillic_and_mic' },
 { oid => '4321',
   descr => 'internal conversion function for WIN866 to ISO-8859-5',
-  proname => 'win866_to_iso', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'win866_to_iso',
+  proname => 'win866_to_iso', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'win866_to_iso',
   probin => '$libdir/cyrillic_and_mic' },
 { oid => '4322',
   descr => 'internal conversion function for EUC_CN to MULE_INTERNAL',
-  proname => 'euc_cn_to_mic', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'euc_cn_to_mic',
+  proname => 'euc_cn_to_mic', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'euc_cn_to_mic',
   probin => '$libdir/euc_cn_and_mic' },
 { oid => '4323',
   descr => 'internal conversion function for MULE_INTERNAL to EUC_CN',
-  proname => 'mic_to_euc_cn', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'mic_to_euc_cn',
+  proname => 'mic_to_euc_cn', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'mic_to_euc_cn',
   probin => '$libdir/euc_cn_and_mic' },
 { oid => '4324', descr => 'internal conversion function for EUC_JP to SJIS',
-  proname => 'euc_jp_to_sjis', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'euc_jp_to_sjis',
+  proname => 'euc_jp_to_sjis', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'euc_jp_to_sjis',
   probin => '$libdir/euc_jp_and_sjis' },
 { oid => '4325', descr => 'internal conversion function for SJIS to EUC_JP',
-  proname => 'sjis_to_euc_jp', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'sjis_to_euc_jp',
+  proname => 'sjis_to_euc_jp', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'sjis_to_euc_jp',
   probin => '$libdir/euc_jp_and_sjis' },
 { oid => '4326',
   descr => 'internal conversion function for EUC_JP to MULE_INTERNAL',
-  proname => 'euc_jp_to_mic', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'euc_jp_to_mic',
+  proname => 'euc_jp_to_mic', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'euc_jp_to_mic',
   probin => '$libdir/euc_jp_and_sjis' },
 { oid => '4327',
   descr => 'internal conversion function for SJIS to MULE_INTERNAL',
-  proname => 'sjis_to_mic', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'sjis_to_mic',
+  proname => 'sjis_to_mic', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'sjis_to_mic',
   probin => '$libdir/euc_jp_and_sjis' },
 { oid => '4328',
   descr => 'internal conversion function for MULE_INTERNAL to EUC_JP',
-  proname => 'mic_to_euc_jp', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'mic_to_euc_jp',
+  proname => 'mic_to_euc_jp', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'mic_to_euc_jp',
   probin => '$libdir/euc_jp_and_sjis' },
 { oid => '4329',
   descr => 'internal conversion function for MULE_INTERNAL to SJIS',
-  proname => 'mic_to_sjis', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'mic_to_sjis',
+  proname => 'mic_to_sjis', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'mic_to_sjis',
   probin => '$libdir/euc_jp_and_sjis' },
 { oid => '4330',
   descr => 'internal conversion function for EUC_KR to MULE_INTERNAL',
-  proname => 'euc_kr_to_mic', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'euc_kr_to_mic',
+  proname => 'euc_kr_to_mic', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'euc_kr_to_mic',
   probin => '$libdir/euc_kr_and_mic' },
 { oid => '4331',
   descr => 'internal conversion function for MULE_INTERNAL to EUC_KR',
-  proname => 'mic_to_euc_kr', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'mic_to_euc_kr',
+  proname => 'mic_to_euc_kr', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'mic_to_euc_kr',
   probin => '$libdir/euc_kr_and_mic' },
 { oid => '4332', descr => 'internal conversion function for EUC_TW to BIG5',
-  proname => 'euc_tw_to_big5', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'euc_tw_to_big5',
+  proname => 'euc_tw_to_big5', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'euc_tw_to_big5',
   probin => '$libdir/euc_tw_and_big5' },
 { oid => '4333', descr => 'internal conversion function for BIG5 to EUC_TW',
-  proname => 'big5_to_euc_tw', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'big5_to_euc_tw',
+  proname => 'big5_to_euc_tw', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'big5_to_euc_tw',
   probin => '$libdir/euc_tw_and_big5' },
 { oid => '4334',
   descr => 'internal conversion function for EUC_TW to MULE_INTERNAL',
-  proname => 'euc_tw_to_mic', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'euc_tw_to_mic',
+  proname => 'euc_tw_to_mic', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'euc_tw_to_mic',
   probin => '$libdir/euc_tw_and_big5' },
 { oid => '4335',
   descr => 'internal conversion function for BIG5 to MULE_INTERNAL',
-  proname => 'big5_to_mic', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'big5_to_mic',
+  proname => 'big5_to_mic', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'big5_to_mic',
   probin => '$libdir/euc_tw_and_big5' },
 { oid => '4336',
   descr => 'internal conversion function for MULE_INTERNAL to EUC_TW',
-  proname => 'mic_to_euc_tw', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'mic_to_euc_tw',
+  proname => 'mic_to_euc_tw', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'mic_to_euc_tw',
   probin => '$libdir/euc_tw_and_big5' },
 { oid => '4337',
   descr => 'internal conversion function for MULE_INTERNAL to BIG5',
-  proname => 'mic_to_big5', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'mic_to_big5',
+  proname => 'mic_to_big5', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'mic_to_big5',
   probin => '$libdir/euc_tw_and_big5' },
 { oid => '4338',
   descr => 'internal conversion function for LATIN2 to MULE_INTERNAL',
-  proname => 'latin2_to_mic', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'latin2_to_mic',
+  proname => 'latin2_to_mic', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'latin2_to_mic',
   probin => '$libdir/latin2_and_win1250' },
 { oid => '4339',
   descr => 'internal conversion function for MULE_INTERNAL to LATIN2',
-  proname => 'mic_to_latin2', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'mic_to_latin2',
+  proname => 'mic_to_latin2', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'mic_to_latin2',
   probin => '$libdir/latin2_and_win1250' },
 { oid => '4340',
   descr => 'internal conversion function for WIN1250 to MULE_INTERNAL',
-  proname => 'win1250_to_mic', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'win1250_to_mic',
+  proname => 'win1250_to_mic', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'win1250_to_mic',
   probin => '$libdir/latin2_and_win1250' },
 { oid => '4341',
   descr => 'internal conversion function for MULE_INTERNAL to WIN1250',
-  proname => 'mic_to_win1250', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'mic_to_win1250',
+  proname => 'mic_to_win1250', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'mic_to_win1250',
   probin => '$libdir/latin2_and_win1250' },
 { oid => '4342',
   descr => 'internal conversion function for LATIN2 to WIN1250',
-  proname => 'latin2_to_win1250', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4',
+  proname => 'latin2_to_win1250', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool',
   prosrc => 'latin2_to_win1250', probin => '$libdir/latin2_and_win1250' },
 { oid => '4343',
   descr => 'internal conversion function for WIN1250 to LATIN2',
-  proname => 'win1250_to_latin2', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4',
+  proname => 'win1250_to_latin2', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool',
   prosrc => 'win1250_to_latin2', probin => '$libdir/latin2_and_win1250' },
 { oid => '4344',
   descr => 'internal conversion function for LATIN1 to MULE_INTERNAL',
-  proname => 'latin1_to_mic', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'latin1_to_mic',
+  proname => 'latin1_to_mic', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'latin1_to_mic',
   probin => '$libdir/latin_and_mic' },
 { oid => '4345',
   descr => 'internal conversion function for MULE_INTERNAL to LATIN1',
-  proname => 'mic_to_latin1', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'mic_to_latin1',
+  proname => 'mic_to_latin1', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'mic_to_latin1',
   probin => '$libdir/latin_and_mic' },
 { oid => '4346',
   descr => 'internal conversion function for LATIN3 to MULE_INTERNAL',
-  proname => 'latin3_to_mic', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'latin3_to_mic',
+  proname => 'latin3_to_mic', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'latin3_to_mic',
   probin => '$libdir/latin_and_mic' },
 { oid => '4347',
   descr => 'internal conversion function for MULE_INTERNAL to LATIN3',
-  proname => 'mic_to_latin3', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'mic_to_latin3',
+  proname => 'mic_to_latin3', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'mic_to_latin3',
   probin => '$libdir/latin_and_mic' },
 { oid => '4348',
   descr => 'internal conversion function for LATIN4 to MULE_INTERNAL',
-  proname => 'latin4_to_mic', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'latin4_to_mic',
+  proname => 'latin4_to_mic', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'latin4_to_mic',
   probin => '$libdir/latin_and_mic' },
 { oid => '4349',
   descr => 'internal conversion function for MULE_INTERNAL to LATIN4',
-  proname => 'mic_to_latin4', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'mic_to_latin4',
+  proname => 'mic_to_latin4', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'mic_to_latin4',
   probin => '$libdir/latin_and_mic' },
 { oid => '4352', descr => 'internal conversion function for BIG5 to UTF8',
-  proname => 'big5_to_utf8', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'big5_to_utf8',
+  proname => 'big5_to_utf8', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'big5_to_utf8',
   probin => '$libdir/utf8_and_big5' },
 { oid => '4353', descr => 'internal conversion function for UTF8 to BIG5',
-  proname => 'utf8_to_big5', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'utf8_to_big5',
+  proname => 'utf8_to_big5', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'utf8_to_big5',
   probin => '$libdir/utf8_and_big5' },
 { oid => '4354', descr => 'internal conversion function for UTF8 to KOI8R',
-  proname => 'utf8_to_koi8r', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'utf8_to_koi8r',
+  proname => 'utf8_to_koi8r', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'utf8_to_koi8r',
   probin => '$libdir/utf8_and_cyrillic' },
 { oid => '4355', descr => 'internal conversion function for KOI8R to UTF8',
-  proname => 'koi8r_to_utf8', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'koi8r_to_utf8',
+  proname => 'koi8r_to_utf8', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'koi8r_to_utf8',
   probin => '$libdir/utf8_and_cyrillic' },
 { oid => '4356', descr => 'internal conversion function for UTF8 to KOI8U',
-  proname => 'utf8_to_koi8u', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'utf8_to_koi8u',
+  proname => 'utf8_to_koi8u', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'utf8_to_koi8u',
   probin => '$libdir/utf8_and_cyrillic' },
 { oid => '4357', descr => 'internal conversion function for KOI8U to UTF8',
-  proname => 'koi8u_to_utf8', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'koi8u_to_utf8',
+  proname => 'koi8u_to_utf8', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'koi8u_to_utf8',
   probin => '$libdir/utf8_and_cyrillic' },
 { oid => '4358', descr => 'internal conversion function for UTF8 to WIN',
-  proname => 'utf8_to_win', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'utf8_to_win',
+  proname => 'utf8_to_win', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'utf8_to_win',
   probin => '$libdir/utf8_and_win' },
 { oid => '4359', descr => 'internal conversion function for WIN to UTF8',
-  proname => 'win_to_utf8', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'win_to_utf8',
+  proname => 'win_to_utf8', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'win_to_utf8',
   probin => '$libdir/utf8_and_win' },
 { oid => '4360', descr => 'internal conversion function for EUC_CN to UTF8',
-  proname => 'euc_cn_to_utf8', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'euc_cn_to_utf8',
+  proname => 'euc_cn_to_utf8', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'euc_cn_to_utf8',
   probin => '$libdir/utf8_and_euc_cn' },
 { oid => '4361', descr => 'internal conversion function for UTF8 to EUC_CN',
-  proname => 'utf8_to_euc_cn', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'utf8_to_euc_cn',
+  proname => 'utf8_to_euc_cn', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'utf8_to_euc_cn',
   probin => '$libdir/utf8_and_euc_cn' },
 { oid => '4362', descr => 'internal conversion function for EUC_JP to UTF8',
-  proname => 'euc_jp_to_utf8', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'euc_jp_to_utf8',
+  proname => 'euc_jp_to_utf8', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'euc_jp_to_utf8',
   probin => '$libdir/utf8_and_euc_jp' },
 { oid => '4363', descr => 'internal conversion function for UTF8 to EUC_JP',
-  proname => 'utf8_to_euc_jp', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'utf8_to_euc_jp',
+  proname => 'utf8_to_euc_jp', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'utf8_to_euc_jp',
   probin => '$libdir/utf8_and_euc_jp' },
 { oid => '4364', descr => 'internal conversion function for EUC_KR to UTF8',
-  proname => 'euc_kr_to_utf8', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'euc_kr_to_utf8',
+  proname => 'euc_kr_to_utf8', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'euc_kr_to_utf8',
   probin => '$libdir/utf8_and_euc_kr' },
 { oid => '4365', descr => 'internal conversion function for UTF8 to EUC_KR',
-  proname => 'utf8_to_euc_kr', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'utf8_to_euc_kr',
+  proname => 'utf8_to_euc_kr', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'utf8_to_euc_kr',
   probin => '$libdir/utf8_and_euc_kr' },
 { oid => '4366', descr => 'internal conversion function for EUC_TW to UTF8',
-  proname => 'euc_tw_to_utf8', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'euc_tw_to_utf8',
+  proname => 'euc_tw_to_utf8', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'euc_tw_to_utf8',
   probin => '$libdir/utf8_and_euc_tw' },
 { oid => '4367', descr => 'internal conversion function for UTF8 to EUC_TW',
-  proname => 'utf8_to_euc_tw', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'utf8_to_euc_tw',
+  proname => 'utf8_to_euc_tw', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'utf8_to_euc_tw',
   probin => '$libdir/utf8_and_euc_tw' },
 { oid => '4368', descr => 'internal conversion function for GB18030 to UTF8',
-  proname => 'gb18030_to_utf8', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'gb18030_to_utf8',
+  proname => 'gb18030_to_utf8', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'gb18030_to_utf8',
   probin => '$libdir/utf8_and_gb18030' },
 { oid => '4369', descr => 'internal conversion function for UTF8 to GB18030',
-  proname => 'utf8_to_gb18030', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'utf8_to_gb18030',
+  proname => 'utf8_to_gb18030', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'utf8_to_gb18030',
   probin => '$libdir/utf8_and_gb18030' },
 { oid => '4370', descr => 'internal conversion function for GBK to UTF8',
-  proname => 'gbk_to_utf8', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'gbk_to_utf8',
+  proname => 'gbk_to_utf8', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'gbk_to_utf8',
   probin => '$libdir/utf8_and_gbk' },
 { oid => '4371', descr => 'internal conversion function for UTF8 to GBK',
-  proname => 'utf8_to_gbk', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'utf8_to_gbk',
+  proname => 'utf8_to_gbk', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'utf8_to_gbk',
   probin => '$libdir/utf8_and_gbk' },
 { oid => '4372',
   descr => 'internal conversion function for UTF8 to ISO-8859 2-16',
-  proname => 'utf8_to_iso8859', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'utf8_to_iso8859',
+  proname => 'utf8_to_iso8859', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'utf8_to_iso8859',
   probin => '$libdir/utf8_and_iso8859' },
 { oid => '4373',
   descr => 'internal conversion function for ISO-8859 2-16 to UTF8',
-  proname => 'iso8859_to_utf8', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'iso8859_to_utf8',
+  proname => 'iso8859_to_utf8', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'iso8859_to_utf8',
   probin => '$libdir/utf8_and_iso8859' },
 { oid => '4374', descr => 'internal conversion function for LATIN1 to UTF8',
-  proname => 'iso8859_1_to_utf8', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4',
+  proname => 'iso8859_1_to_utf8', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool',
   prosrc => 'iso8859_1_to_utf8', probin => '$libdir/utf8_and_iso8859_1' },
 { oid => '4375', descr => 'internal conversion function for UTF8 to LATIN1',
-  proname => 'utf8_to_iso8859_1', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4',
+  proname => 'utf8_to_iso8859_1', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool',
   prosrc => 'utf8_to_iso8859_1', probin => '$libdir/utf8_and_iso8859_1' },
 { oid => '4376', descr => 'internal conversion function for JOHAB to UTF8',
-  proname => 'johab_to_utf8', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'johab_to_utf8',
+  proname => 'johab_to_utf8', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'johab_to_utf8',
   probin => '$libdir/utf8_and_johab' },
 { oid => '4377', descr => 'internal conversion function for UTF8 to JOHAB',
-  proname => 'utf8_to_johab', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'utf8_to_johab',
+  proname => 'utf8_to_johab', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'utf8_to_johab',
   probin => '$libdir/utf8_and_johab' },
 { oid => '4378', descr => 'internal conversion function for SJIS to UTF8',
-  proname => 'sjis_to_utf8', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'sjis_to_utf8',
+  proname => 'sjis_to_utf8', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'sjis_to_utf8',
   probin => '$libdir/utf8_and_sjis' },
 { oid => '4379', descr => 'internal conversion function for UTF8 to SJIS',
-  proname => 'utf8_to_sjis', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'utf8_to_sjis',
+  proname => 'utf8_to_sjis', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'utf8_to_sjis',
   probin => '$libdir/utf8_and_sjis' },
 { oid => '4380', descr => 'internal conversion function for UHC to UTF8',
-  proname => 'uhc_to_utf8', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'uhc_to_utf8',
+  proname => 'uhc_to_utf8', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'uhc_to_utf8',
   probin => '$libdir/utf8_and_uhc' },
 { oid => '4381', descr => 'internal conversion function for UTF8 to UHC',
-  proname => 'utf8_to_uhc', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4', prosrc => 'utf8_to_uhc',
+  proname => 'utf8_to_uhc', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool', prosrc => 'utf8_to_uhc',
   probin => '$libdir/utf8_and_uhc' },
 { oid => '4382',
   descr => 'internal conversion function for EUC_JIS_2004 to UTF8',
-  proname => 'euc_jis_2004_to_utf8', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4',
+  proname => 'euc_jis_2004_to_utf8', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool',
   prosrc => 'euc_jis_2004_to_utf8', probin => '$libdir/utf8_and_euc2004' },
 { oid => '4383',
   descr => 'internal conversion function for UTF8 to EUC_JIS_2004',
-  proname => 'utf8_to_euc_jis_2004', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4',
+  proname => 'utf8_to_euc_jis_2004', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool',
   prosrc => 'utf8_to_euc_jis_2004', probin => '$libdir/utf8_and_euc2004' },
 { oid => '4384',
   descr => 'internal conversion function for SHIFT_JIS_2004 to UTF8',
-  proname => 'shift_jis_2004_to_utf8', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4',
+  proname => 'shift_jis_2004_to_utf8', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool',
   prosrc => 'shift_jis_2004_to_utf8', probin => '$libdir/utf8_and_sjis2004' },
 { oid => '4385',
   descr => 'internal conversion function for UTF8 to SHIFT_JIS_2004',
-  proname => 'utf8_to_shift_jis_2004', prolang => 'c', prorettype => 'void',
-  proargtypes => 'int4 int4 cstring internal int4',
+  proname => 'utf8_to_shift_jis_2004', prolang => 'c', prorettype => 'int4',
+  proargtypes => 'int4 int4 cstring internal int4 bool',
   prosrc => 'utf8_to_shift_jis_2004', probin => '$libdir/utf8_and_sjis2004' },
 { oid => '4386',
   descr => 'internal conversion function for EUC_JIS_2004 to SHIFT_JIS_2004',
   proname => 'euc_jis_2004_to_shift_jis_2004', prolang => 'c',
-  prorettype => 'void', proargtypes => 'int4 int4 cstring internal int4',
+  prorettype => 'int4', proargtypes => 'int4 int4 cstring internal int4 bool',
   prosrc => 'euc_jis_2004_to_shift_jis_2004',
   probin => '$libdir/euc2004_sjis2004' },
 { oid => '4387',
   descr => 'internal conversion function for SHIFT_JIS_2004 to EUC_JIS_2004',
   proname => 'shift_jis_2004_to_euc_jis_2004', prolang => 'c',
-  prorettype => 'void', proargtypes => 'int4 int4 cstring internal int4',
+  prorettype => 'int4', proargtypes => 'int4 int4 cstring internal int4 bool',
   prosrc => 'shift_jis_2004_to_euc_jis_2004',
   probin => '$libdir/euc2004_sjis2004' },
 
diff --git a/src/include/mb/pg_wchar.h b/src/include/mb/pg_wchar.h
index 64b22e4b0d4..a9aaff9e6dc 100644
--- a/src/include/mb/pg_wchar.h
+++ b/src/include/mb/pg_wchar.h
@@ -616,6 +616,12 @@ extern int	pg_bind_textdomain_codeset(const char *domainname);
 extern unsigned char *pg_do_encoding_conversion(unsigned char *src, int len,
 												int src_encoding,
 												int dest_encoding);
+extern int	pg_do_encoding_conversion_buf(Oid proc,
+										  int src_encoding,
+										  int dest_encoding,
+										  unsigned char *src, int srclen,
+										  unsigned char *dst, int dstlen,
+										  bool noError);
 
 extern char *pg_client_to_server(const char *s, int len);
 extern char *pg_server_to_client(const char *s, int len);
@@ -627,18 +633,18 @@ extern void pg_unicode_to_server(pg_wchar c, unsigned char *s);
 extern unsigned short BIG5toCNS(unsigned short big5, unsigned char *lc);
 extern unsigned short CNStoBIG5(unsigned short cns, unsigned char lc);
 
-extern void UtfToLocal(const unsigned char *utf, int len,
+extern int	UtfToLocal(const unsigned char *utf, int len,
 					   unsigned char *iso,
 					   const pg_mb_radix_tree *map,
 					   const pg_utf_to_local_combined *cmap, int cmapsize,
 					   utf_local_conversion_func conv_func,
-					   int encoding);
-extern void LocalToUtf(const unsigned char *iso, int len,
+					   int encoding, bool noError);
+extern int	LocalToUtf(const unsigned char *iso, int len,
 					   unsigned char *utf,
 					   const pg_mb_radix_tree *map,
 					   const pg_local_to_utf_combined *cmap, int cmapsize,
 					   utf_local_conversion_func conv_func,
-					   int encoding);
+					   int encoding, bool noError);
 
 extern bool pg_verifymbstr(const char *mbstr, int len, bool noError);
 extern bool pg_verify_mbstr(int encoding, const char *mbstr, int len,
@@ -656,18 +662,19 @@ extern void report_invalid_encoding(int encoding, const char *mbstr, int len) pg
 extern void report_untranslatable_char(int src_encoding, int dest_encoding,
 									   const char *mbstr, int len) pg_attribute_noreturn();
 
-extern void local2local(const unsigned char *l, unsigned char *p, int len,
-						int src_encoding, int dest_encoding, const unsigned char *tab);
-extern void latin2mic(const unsigned char *l, unsigned char *p, int len,
-					  int lc, int encoding);
-extern void mic2latin(const unsigned char *mic, unsigned char *p, int len,
-					  int lc, int encoding);
-extern void latin2mic_with_table(const unsigned char *l, unsigned char *p,
+extern int	local2local(const unsigned char *l, unsigned char *p, int len,
+						int src_encoding, int dest_encoding,
+						const unsigned char *tab, bool noError);
+extern int	latin2mic(const unsigned char *l, unsigned char *p, int len,
+					  int lc, int encoding, bool noError);
+extern int	mic2latin(const unsigned char *mic, unsigned char *p, int len,
+					  int lc, int encoding, bool noError);
+extern int	latin2mic_with_table(const unsigned char *l, unsigned char *p,
 								 int len, int lc, int encoding,
-								 const unsigned char *tab);
-extern void mic2latin_with_table(const unsigned char *mic, unsigned char *p,
+								 const unsigned char *tab, bool noError);
+extern int	mic2latin_with_table(const unsigned char *mic, unsigned char *p,
 								 int len, int lc, int encoding,
-								 const unsigned char *tab);
+								 const unsigned char *tab, bool noError);
 
 #ifdef WIN32
 extern WCHAR *pgwin32_message_to_UTF16(const char *str, int len, int *utf16len);
diff --git a/src/test/regress/expected/conversion.out b/src/test/regress/expected/conversion.out
index 62c10671685..e34ab20974d 100644
--- a/src/test/regress/expected/conversion.out
+++ b/src/test/regress/expected/conversion.out
@@ -37,3 +37,522 @@ DROP CONVERSION mydef;
 --
 RESET SESSION AUTHORIZATION;
 DROP USER regress_conversion_user;
+--
+-- Test built-in conversion functions.
+--
+-- Helper function to test a conversion. Uses the test_enc_conversion function
+-- that was created in the create_function_1 test.
+create or replace function test_conv(
+  input IN bytea,
+  src_encoding IN text,
+  dst_encoding IN text,
+  result OUT bytea,
+  errorat OUT bytea,
+  error OUT text)
+language plpgsql as
+$$
+declare
+  validlen int;
+begin
+  -- First try to perform the conversion with noError = false. If that errors out,
+  -- capture the error message, and try again with noError = true. The second call
+  -- should succeed and return the position of the error, return that too.
+  begin
+    select * into validlen, result from test_enc_conversion(input, src_encoding, dst_encoding, false);
+    errorat = NULL;
+    error := NULL;
+  exception when others then
+    error := sqlerrm;
+    select * into validlen, result from test_enc_conversion(input, src_encoding, dst_encoding, true);
+    errorat = substr(input, validlen + 1);
+  end;
+  return;
+end;
+$$;
+--
+-- UTF-8
+--
+CREATE TABLE utf8_inputs (inbytes bytea, description text);
+insert into utf8_inputs  values
+  ('\x666f6f',		'valid, pure ASCII'),
+  ('\xc3a4c3b6',	'valid, extra latin chars'),
+  ('\xd184d0bed0be',	'valid, cyrillic'),
+  ('\x666f6fe8b1a1',	'valid, kanji/Chinese'),
+  ('\xe382abe3829a',	'valid, two chars that combine to one in EUC_JIS_2004'),
+  ('\xe382ab',		'only first half of combined char in EUC_JIS_2004'),
+  ('\xe382abe382',	'incomplete combination when converted EUC_JIS_2004'),
+  ('\xecbd94eb81bceba6ac', 'valid, Hangul, Korean'),
+  ('\x666f6fefa8aa',	'valid, needs mapping function to convert to GB18030'),
+  ('\x66e8b1ff6f6f',	'invalid byte sequence'),
+  ('\x66006f',		'invalid, NUL byte'),
+  ('\x666f6fe8b100',	'invalid, NUL byte'),
+  ('\x666f6fe8b1',	'incomplete character at end');
+-- Test UTF-8 verification
+select description, (test_conv(inbytes, 'utf8', 'utf8')).* from utf8_inputs;
+                     description                      |        result        |   errorat    |                           error                           
+------------------------------------------------------+----------------------+--------------+-----------------------------------------------------------
+ valid, pure ASCII                                    | \x666f6f             |              | 
+ valid, extra latin chars                             | \xc3a4c3b6           |              | 
+ valid, cyrillic                                      | \xd184d0bed0be       |              | 
+ valid, kanji/Chinese                                 | \x666f6fe8b1a1       |              | 
+ valid, two chars that combine to one in EUC_JIS_2004 | \xe382abe3829a       |              | 
+ only first half of combined char in EUC_JIS_2004     | \xe382ab             |              | 
+ incomplete combination when converted EUC_JIS_2004   | \xe382ab             | \xe382       | invalid byte sequence for encoding "UTF8": 0xe3 0x82
+ valid, Hangul, Korean                                | \xecbd94eb81bceba6ac |              | 
+ valid, needs mapping function to convert to GB18030  | \x666f6fefa8aa       |              | 
+ invalid byte sequence                                | \x66                 | \xe8b1ff6f6f | invalid byte sequence for encoding "UTF8": 0xe8 0xb1 0xff
+ invalid, NUL byte                                    | \x66                 | \x006f       | invalid byte sequence for encoding "UTF8": 0x00
+ invalid, NUL byte                                    | \x666f6f             | \xe8b100     | invalid byte sequence for encoding "UTF8": 0xe8 0xb1 0x00
+ incomplete character at end                          | \x666f6f             | \xe8b1       | invalid byte sequence for encoding "UTF8": 0xe8 0xb1
+(13 rows)
+
+-- Test conversions from UTF-8
+select description, inbytes, (test_conv(inbytes, 'utf8', 'euc_jis_2004')).* from utf8_inputs;
+                     description                      |       inbytes        |     result     |       errorat        |                                                    error                                                    
+------------------------------------------------------+----------------------+----------------+----------------------+-------------------------------------------------------------------------------------------------------------
+ valid, pure ASCII                                    | \x666f6f             | \x666f6f       |                      | 
+ valid, extra latin chars                             | \xc3a4c3b6           | \xa9daa9ec     |                      | 
+ valid, cyrillic                                      | \xd184d0bed0be       | \xa7e6a7e0a7e0 |                      | 
+ valid, kanji/Chinese                                 | \x666f6fe8b1a1       | \x666f6fbedd   |                      | 
+ valid, two chars that combine to one in EUC_JIS_2004 | \xe382abe3829a       | \xa5f7         |                      | 
+ only first half of combined char in EUC_JIS_2004     | \xe382ab             | \xa5ab         |                      | 
+ incomplete combination when converted EUC_JIS_2004   | \xe382abe382         | \x             | \xe382abe382         | invalid byte sequence for encoding "UTF8": 0xe3 0x82
+ valid, Hangul, Korean                                | \xecbd94eb81bceba6ac | \x             | \xecbd94eb81bceba6ac | character with byte sequence 0xec 0xbd 0x94 in encoding "UTF8" has no equivalent in encoding "EUC_JIS_2004"
+ valid, needs mapping function to convert to GB18030  | \x666f6fefa8aa       | \x666f6f       | \xefa8aa             | character with byte sequence 0xef 0xa8 0xaa in encoding "UTF8" has no equivalent in encoding "EUC_JIS_2004"
+ invalid byte sequence                                | \x66e8b1ff6f6f       | \x66           | \xe8b1ff6f6f         | invalid byte sequence for encoding "UTF8": 0xe8 0xb1 0xff
+ invalid, NUL byte                                    | \x66006f             | \x66           | \x006f               | invalid byte sequence for encoding "UTF8": 0x00
+ invalid, NUL byte                                    | \x666f6fe8b100       | \x666f6f       | \xe8b100             | invalid byte sequence for encoding "UTF8": 0xe8 0xb1 0x00
+ incomplete character at end                          | \x666f6fe8b1         | \x666f6f       | \xe8b1               | invalid byte sequence for encoding "UTF8": 0xe8 0xb1
+(13 rows)
+
+select description, inbytes, (test_conv(inbytes, 'utf8', 'latin1')).* from utf8_inputs;
+                     description                      |       inbytes        |  result  |       errorat        |                                                 error                                                 
+------------------------------------------------------+----------------------+----------+----------------------+-------------------------------------------------------------------------------------------------------
+ valid, pure ASCII                                    | \x666f6f             | \x666f6f |                      | 
+ valid, extra latin chars                             | \xc3a4c3b6           | \xe4f6   |                      | 
+ valid, cyrillic                                      | \xd184d0bed0be       | \x       | \xd184d0bed0be       | character with byte sequence 0xd1 0x84 in encoding "UTF8" has no equivalent in encoding "LATIN1"
+ valid, kanji/Chinese                                 | \x666f6fe8b1a1       | \x666f6f | \xe8b1a1             | character with byte sequence 0xe8 0xb1 0xa1 in encoding "UTF8" has no equivalent in encoding "LATIN1"
+ valid, two chars that combine to one in EUC_JIS_2004 | \xe382abe3829a       | \x       | \xe382abe3829a       | character with byte sequence 0xe3 0x82 0xab in encoding "UTF8" has no equivalent in encoding "LATIN1"
+ only first half of combined char in EUC_JIS_2004     | \xe382ab             | \x       | \xe382ab             | character with byte sequence 0xe3 0x82 0xab in encoding "UTF8" has no equivalent in encoding "LATIN1"
+ incomplete combination when converted EUC_JIS_2004   | \xe382abe382         | \x       | \xe382abe382         | character with byte sequence 0xe3 0x82 0xab in encoding "UTF8" has no equivalent in encoding "LATIN1"
+ valid, Hangul, Korean                                | \xecbd94eb81bceba6ac | \x       | \xecbd94eb81bceba6ac | character with byte sequence 0xec 0xbd 0x94 in encoding "UTF8" has no equivalent in encoding "LATIN1"
+ valid, needs mapping function to convert to GB18030  | \x666f6fefa8aa       | \x666f6f | \xefa8aa             | character with byte sequence 0xef 0xa8 0xaa in encoding "UTF8" has no equivalent in encoding "LATIN1"
+ invalid byte sequence                                | \x66e8b1ff6f6f       | \x66     | \xe8b1ff6f6f         | invalid byte sequence for encoding "UTF8": 0xe8 0xb1 0xff
+ invalid, NUL byte                                    | \x66006f             | \x66     | \x006f               | invalid byte sequence for encoding "UTF8": 0x00
+ invalid, NUL byte                                    | \x666f6fe8b100       | \x666f6f | \xe8b100             | invalid byte sequence for encoding "UTF8": 0xe8 0xb1 0x00
+ incomplete character at end                          | \x666f6fe8b1         | \x666f6f | \xe8b1               | invalid byte sequence for encoding "UTF8": 0xe8 0xb1
+(13 rows)
+
+select description, inbytes, (test_conv(inbytes, 'utf8', 'latin2')).* from utf8_inputs;
+                     description                      |       inbytes        |  result  |       errorat        |                                                 error                                                 
+------------------------------------------------------+----------------------+----------+----------------------+-------------------------------------------------------------------------------------------------------
+ valid, pure ASCII                                    | \x666f6f             | \x666f6f |                      | 
+ valid, extra latin chars                             | \xc3a4c3b6           | \xe4f6   |                      | 
+ valid, cyrillic                                      | \xd184d0bed0be       | \x       | \xd184d0bed0be       | character with byte sequence 0xd1 0x84 in encoding "UTF8" has no equivalent in encoding "LATIN2"
+ valid, kanji/Chinese                                 | \x666f6fe8b1a1       | \x666f6f | \xe8b1a1             | character with byte sequence 0xe8 0xb1 0xa1 in encoding "UTF8" has no equivalent in encoding "LATIN2"
+ valid, two chars that combine to one in EUC_JIS_2004 | \xe382abe3829a       | \x       | \xe382abe3829a       | character with byte sequence 0xe3 0x82 0xab in encoding "UTF8" has no equivalent in encoding "LATIN2"
+ only first half of combined char in EUC_JIS_2004     | \xe382ab             | \x       | \xe382ab             | character with byte sequence 0xe3 0x82 0xab in encoding "UTF8" has no equivalent in encoding "LATIN2"
+ incomplete combination when converted EUC_JIS_2004   | \xe382abe382         | \x       | \xe382abe382         | character with byte sequence 0xe3 0x82 0xab in encoding "UTF8" has no equivalent in encoding "LATIN2"
+ valid, Hangul, Korean                                | \xecbd94eb81bceba6ac | \x       | \xecbd94eb81bceba6ac | character with byte sequence 0xec 0xbd 0x94 in encoding "UTF8" has no equivalent in encoding "LATIN2"
+ valid, needs mapping function to convert to GB18030  | \x666f6fefa8aa       | \x666f6f | \xefa8aa             | character with byte sequence 0xef 0xa8 0xaa in encoding "UTF8" has no equivalent in encoding "LATIN2"
+ invalid byte sequence                                | \x66e8b1ff6f6f       | \x66     | \xe8b1ff6f6f         | invalid byte sequence for encoding "UTF8": 0xe8 0xb1 0xff
+ invalid, NUL byte                                    | \x66006f             | \x66     | \x006f               | invalid byte sequence for encoding "UTF8": 0x00
+ invalid, NUL byte                                    | \x666f6fe8b100       | \x666f6f | \xe8b100             | invalid byte sequence for encoding "UTF8": 0xe8 0xb1 0x00
+ incomplete character at end                          | \x666f6fe8b1         | \x666f6f | \xe8b1               | invalid byte sequence for encoding "UTF8": 0xe8 0xb1
+(13 rows)
+
+select description, inbytes, (test_conv(inbytes, 'utf8', 'latin5')).* from utf8_inputs;
+                     description                      |       inbytes        |  result  |       errorat        |                                                 error                                                 
+------------------------------------------------------+----------------------+----------+----------------------+-------------------------------------------------------------------------------------------------------
+ valid, pure ASCII                                    | \x666f6f             | \x666f6f |                      | 
+ valid, extra latin chars                             | \xc3a4c3b6           | \xe4f6   |                      | 
+ valid, cyrillic                                      | \xd184d0bed0be       | \x       | \xd184d0bed0be       | character with byte sequence 0xd1 0x84 in encoding "UTF8" has no equivalent in encoding "LATIN5"
+ valid, kanji/Chinese                                 | \x666f6fe8b1a1       | \x666f6f | \xe8b1a1             | character with byte sequence 0xe8 0xb1 0xa1 in encoding "UTF8" has no equivalent in encoding "LATIN5"
+ valid, two chars that combine to one in EUC_JIS_2004 | \xe382abe3829a       | \x       | \xe382abe3829a       | character with byte sequence 0xe3 0x82 0xab in encoding "UTF8" has no equivalent in encoding "LATIN5"
+ only first half of combined char in EUC_JIS_2004     | \xe382ab             | \x       | \xe382ab             | character with byte sequence 0xe3 0x82 0xab in encoding "UTF8" has no equivalent in encoding "LATIN5"
+ incomplete combination when converted EUC_JIS_2004   | \xe382abe382         | \x       | \xe382abe382         | character with byte sequence 0xe3 0x82 0xab in encoding "UTF8" has no equivalent in encoding "LATIN5"
+ valid, Hangul, Korean                                | \xecbd94eb81bceba6ac | \x       | \xecbd94eb81bceba6ac | character with byte sequence 0xec 0xbd 0x94 in encoding "UTF8" has no equivalent in encoding "LATIN5"
+ valid, needs mapping function to convert to GB18030  | \x666f6fefa8aa       | \x666f6f | \xefa8aa             | character with byte sequence 0xef 0xa8 0xaa in encoding "UTF8" has no equivalent in encoding "LATIN5"
+ invalid byte sequence                                | \x66e8b1ff6f6f       | \x66     | \xe8b1ff6f6f         | invalid byte sequence for encoding "UTF8": 0xe8 0xb1 0xff
+ invalid, NUL byte                                    | \x66006f             | \x66     | \x006f               | invalid byte sequence for encoding "UTF8": 0x00
+ invalid, NUL byte                                    | \x666f6fe8b100       | \x666f6f | \xe8b100             | invalid byte sequence for encoding "UTF8": 0xe8 0xb1 0x00
+ incomplete character at end                          | \x666f6fe8b1         | \x666f6f | \xe8b1               | invalid byte sequence for encoding "UTF8": 0xe8 0xb1
+(13 rows)
+
+select description, inbytes, (test_conv(inbytes, 'utf8', 'koi8r')).* from utf8_inputs;
+                     description                      |       inbytes        |  result  |       errorat        |                                                error                                                 
+------------------------------------------------------+----------------------+----------+----------------------+------------------------------------------------------------------------------------------------------
+ valid, pure ASCII                                    | \x666f6f             | \x666f6f |                      | 
+ valid, extra latin chars                             | \xc3a4c3b6           | \x       | \xc3a4c3b6           | character with byte sequence 0xc3 0xa4 in encoding "UTF8" has no equivalent in encoding "KOI8R"
+ valid, cyrillic                                      | \xd184d0bed0be       | \xc6cfcf |                      | 
+ valid, kanji/Chinese                                 | \x666f6fe8b1a1       | \x666f6f | \xe8b1a1             | character with byte sequence 0xe8 0xb1 0xa1 in encoding "UTF8" has no equivalent in encoding "KOI8R"
+ valid, two chars that combine to one in EUC_JIS_2004 | \xe382abe3829a       | \x       | \xe382abe3829a       | character with byte sequence 0xe3 0x82 0xab in encoding "UTF8" has no equivalent in encoding "KOI8R"
+ only first half of combined char in EUC_JIS_2004     | \xe382ab             | \x       | \xe382ab             | character with byte sequence 0xe3 0x82 0xab in encoding "UTF8" has no equivalent in encoding "KOI8R"
+ incomplete combination when converted EUC_JIS_2004   | \xe382abe382         | \x       | \xe382abe382         | character with byte sequence 0xe3 0x82 0xab in encoding "UTF8" has no equivalent in encoding "KOI8R"
+ valid, Hangul, Korean                                | \xecbd94eb81bceba6ac | \x       | \xecbd94eb81bceba6ac | character with byte sequence 0xec 0xbd 0x94 in encoding "UTF8" has no equivalent in encoding "KOI8R"
+ valid, needs mapping function to convert to GB18030  | \x666f6fefa8aa       | \x666f6f | \xefa8aa             | character with byte sequence 0xef 0xa8 0xaa in encoding "UTF8" has no equivalent in encoding "KOI8R"
+ invalid byte sequence                                | \x66e8b1ff6f6f       | \x66     | \xe8b1ff6f6f         | invalid byte sequence for encoding "UTF8": 0xe8 0xb1 0xff
+ invalid, NUL byte                                    | \x66006f             | \x66     | \x006f               | invalid byte sequence for encoding "UTF8": 0x00
+ invalid, NUL byte                                    | \x666f6fe8b100       | \x666f6f | \xe8b100             | invalid byte sequence for encoding "UTF8": 0xe8 0xb1 0x00
+ incomplete character at end                          | \x666f6fe8b1         | \x666f6f | \xe8b1               | invalid byte sequence for encoding "UTF8": 0xe8 0xb1
+(13 rows)
+
+select description, inbytes, (test_conv(inbytes, 'utf8', 'gb18030')).* from utf8_inputs;
+                     description                      |       inbytes        |           result           |   errorat    |                           error                           
+------------------------------------------------------+----------------------+----------------------------+--------------+-----------------------------------------------------------
+ valid, pure ASCII                                    | \x666f6f             | \x666f6f                   |              | 
+ valid, extra latin chars                             | \xc3a4c3b6           | \x81308a3181308b32         |              | 
+ valid, cyrillic                                      | \xd184d0bed0be       | \xa7e6a7e0a7e0             |              | 
+ valid, kanji/Chinese                                 | \x666f6fe8b1a1       | \x666f6fcff3               |              | 
+ valid, two chars that combine to one in EUC_JIS_2004 | \xe382abe3829a       | \xa5ab8139a732             |              | 
+ only first half of combined char in EUC_JIS_2004     | \xe382ab             | \xa5ab                     |              | 
+ incomplete combination when converted EUC_JIS_2004   | \xe382abe382         | \xa5ab                     | \xe382       | invalid byte sequence for encoding "UTF8": 0xe3 0x82
+ valid, Hangul, Korean                                | \xecbd94eb81bceba6ac | \x8334e5398238c4338330b335 |              | 
+ valid, needs mapping function to convert to GB18030  | \x666f6fefa8aa       | \x666f6f84309c38           |              | 
+ invalid byte sequence                                | \x66e8b1ff6f6f       | \x66                       | \xe8b1ff6f6f | invalid byte sequence for encoding "UTF8": 0xe8 0xb1 0xff
+ invalid, NUL byte                                    | \x66006f             | \x66                       | \x006f       | invalid byte sequence for encoding "UTF8": 0x00
+ invalid, NUL byte                                    | \x666f6fe8b100       | \x666f6f                   | \xe8b100     | invalid byte sequence for encoding "UTF8": 0xe8 0xb1 0x00
+ incomplete character at end                          | \x666f6fe8b1         | \x666f6f                   | \xe8b1       | invalid byte sequence for encoding "UTF8": 0xe8 0xb1
+(13 rows)
+
+--
+-- EUC_JIS_2004
+--
+CREATE TABLE euc_jis_2004_inputs (inbytes bytea, description text);
+insert into euc_jis_2004_inputs  values
+  ('\x666f6f',		'valid, pure ASCII'),
+  ('\x666f6fbedd',	'valid'),
+  ('\xa5f7',		'valid, translates to two UTF-8 chars '),
+  ('\xbeddbe',		'incomplete char '),
+  ('\x666f6f00bedd',	'invalid, NUL byte'),
+  ('\x666f6fbe00dd',	'invalid, NUL byte'),
+  ('\x666f6fbedd00',	'invalid, NUL byte'),
+  ('\xbe04',		'invalid byte sequence');
+-- Test EUC_JIS_2004 verification
+select description, inbytes, (test_conv(inbytes, 'euc_jis_2004', 'euc_jis_2004')).* from euc_jis_2004_inputs;
+              description              |    inbytes     |    result    | errorat  |                            error                             
+---------------------------------------+----------------+--------------+----------+--------------------------------------------------------------
+ valid, pure ASCII                     | \x666f6f       | \x666f6f     |          | 
+ valid                                 | \x666f6fbedd   | \x666f6fbedd |          | 
+ valid, translates to two UTF-8 chars  | \xa5f7         | \xa5f7       |          | 
+ incomplete char                       | \xbeddbe       | \xbedd       | \xbe     | invalid byte sequence for encoding "EUC_JIS_2004": 0xbe
+ invalid, NUL byte                     | \x666f6f00bedd | \x666f6f     | \x00bedd | invalid byte sequence for encoding "EUC_JIS_2004": 0x00
+ invalid, NUL byte                     | \x666f6fbe00dd | \x666f6f     | \xbe00dd | invalid byte sequence for encoding "EUC_JIS_2004": 0xbe 0x00
+ invalid, NUL byte                     | \x666f6fbedd00 | \x666f6fbedd | \x00     | invalid byte sequence for encoding "EUC_JIS_2004": 0x00
+ invalid byte sequence                 | \xbe04         | \x           | \xbe04   | invalid byte sequence for encoding "EUC_JIS_2004": 0xbe 0x04
+(8 rows)
+
+-- Test conversions from EUC_JIS_2004
+select description, inbytes, (test_conv(inbytes, 'euc_jis_2004', 'utf8')).* from euc_jis_2004_inputs;
+              description              |    inbytes     |     result     | errorat  |                            error                             
+---------------------------------------+----------------+----------------+----------+--------------------------------------------------------------
+ valid, pure ASCII                     | \x666f6f       | \x666f6f       |          | 
+ valid                                 | \x666f6fbedd   | \x666f6fe8b1a1 |          | 
+ valid, translates to two UTF-8 chars  | \xa5f7         | \xe382abe3829a |          | 
+ incomplete char                       | \xbeddbe       | \xe8b1a1       | \xbe     | invalid byte sequence for encoding "EUC_JIS_2004": 0xbe
+ invalid, NUL byte                     | \x666f6f00bedd | \x666f6f       | \x00bedd | invalid byte sequence for encoding "EUC_JIS_2004": 0x00
+ invalid, NUL byte                     | \x666f6fbe00dd | \x666f6f       | \xbe00dd | invalid byte sequence for encoding "EUC_JIS_2004": 0xbe 0x00
+ invalid, NUL byte                     | \x666f6fbedd00 | \x666f6fe8b1a1 | \x00     | invalid byte sequence for encoding "EUC_JIS_2004": 0x00
+ invalid byte sequence                 | \xbe04         | \x             | \xbe04   | invalid byte sequence for encoding "EUC_JIS_2004": 0xbe 0x04
+(8 rows)
+
+--
+-- SHIFT-JIS-2004
+--
+CREATE TABLE shiftjis2004_inputs (inbytes bytea, description text);
+insert into shiftjis2004_inputs  values
+  ('\x666f6f',		'valid, pure ASCII'),
+  ('\x666f6f8fdb',	'valid'),
+  ('\x666f6f81c0',	'valid, no translation to UTF-8'),
+  ('\x666f6f82f5',	'valid, translates to two UTF-8 chars '),
+  ('\x666f6f8fdb8f',	'incomplete char '),
+  ('\x666f6f820a',	'incomplete char, followed by newline '),
+  ('\x666f6f008fdb',	'invalid, NUL byte'),
+  ('\x666f6f8f00db',	'invalid, NUL byte'),
+  ('\x666f6f8fdb00',	'invalid, NUL byte');
+-- Test SHIFT-JIS-2004 verification
+select description, inbytes, (test_conv(inbytes, 'shiftjis2004', 'shiftjis2004')).* from shiftjis2004_inputs;
+              description              |    inbytes     |    result    | errorat  |                             error                              
+---------------------------------------+----------------+--------------+----------+----------------------------------------------------------------
+ valid, pure ASCII                     | \x666f6f       | \x666f6f     |          | 
+ valid                                 | \x666f6f8fdb   | \x666f6f8fdb |          | 
+ valid, no translation to UTF-8        | \x666f6f81c0   | \x666f6f81c0 |          | 
+ valid, translates to two UTF-8 chars  | \x666f6f82f5   | \x666f6f82f5 |          | 
+ incomplete char                       | \x666f6f8fdb8f | \x666f6f8fdb | \x8f     | invalid byte sequence for encoding "SHIFT_JIS_2004": 0x8f
+ incomplete char, followed by newline  | \x666f6f820a   | \x666f6f     | \x820a   | invalid byte sequence for encoding "SHIFT_JIS_2004": 0x82 0x0a
+ invalid, NUL byte                     | \x666f6f008fdb | \x666f6f     | \x008fdb | invalid byte sequence for encoding "SHIFT_JIS_2004": 0x00
+ invalid, NUL byte                     | \x666f6f8f00db | \x666f6f     | \x8f00db | invalid byte sequence for encoding "SHIFT_JIS_2004": 0x8f 0x00
+ invalid, NUL byte                     | \x666f6f8fdb00 | \x666f6f8fdb | \x00     | invalid byte sequence for encoding "SHIFT_JIS_2004": 0x00
+(9 rows)
+
+-- Test conversions from SHIFT-JIS-2004
+select description, inbytes, (test_conv(inbytes, 'shiftjis2004', 'utf8')).* from shiftjis2004_inputs;
+              description              |    inbytes     |        result        | errorat  |                             error                              
+---------------------------------------+----------------+----------------------+----------+----------------------------------------------------------------
+ valid, pure ASCII                     | \x666f6f       | \x666f6f             |          | 
+ valid                                 | \x666f6f8fdb   | \x666f6fe8b1a1       |          | 
+ valid, no translation to UTF-8        | \x666f6f81c0   | \x666f6fe28a84       |          | 
+ valid, translates to two UTF-8 chars  | \x666f6f82f5   | \x666f6fe3818be3829a |          | 
+ incomplete char                       | \x666f6f8fdb8f | \x666f6fe8b1a1       | \x8f     | invalid byte sequence for encoding "SHIFT_JIS_2004": 0x8f
+ incomplete char, followed by newline  | \x666f6f820a   | \x666f6f             | \x820a   | invalid byte sequence for encoding "SHIFT_JIS_2004": 0x82 0x0a
+ invalid, NUL byte                     | \x666f6f008fdb | \x666f6f             | \x008fdb | invalid byte sequence for encoding "SHIFT_JIS_2004": 0x00
+ invalid, NUL byte                     | \x666f6f8f00db | \x666f6f             | \x8f00db | invalid byte sequence for encoding "SHIFT_JIS_2004": 0x8f 0x00
+ invalid, NUL byte                     | \x666f6f8fdb00 | \x666f6fe8b1a1       | \x00     | invalid byte sequence for encoding "SHIFT_JIS_2004": 0x00
+(9 rows)
+
+select description, inbytes, (test_conv(inbytes, 'shiftjis2004', 'euc_jis_2004')).* from shiftjis2004_inputs;
+              description              |    inbytes     |    result    | errorat  |                             error                              
+---------------------------------------+----------------+--------------+----------+----------------------------------------------------------------
+ valid, pure ASCII                     | \x666f6f       | \x666f6f     |          | 
+ valid                                 | \x666f6f8fdb   | \x666f6fbedd |          | 
+ valid, no translation to UTF-8        | \x666f6f81c0   | \x666f6fa2c2 |          | 
+ valid, translates to two UTF-8 chars  | \x666f6f82f5   | \x666f6fa4f7 |          | 
+ incomplete char                       | \x666f6f8fdb8f | \x666f6fbedd | \x8f     | invalid byte sequence for encoding "SHIFT_JIS_2004": 0x8f
+ incomplete char, followed by newline  | \x666f6f820a   | \x666f6f     | \x820a   | invalid byte sequence for encoding "SHIFT_JIS_2004": 0x82 0x0a
+ invalid, NUL byte                     | \x666f6f008fdb | \x666f6f     | \x008fdb | invalid byte sequence for encoding "SHIFT_JIS_2004": 0x00
+ invalid, NUL byte                     | \x666f6f8f00db | \x666f6f     | \x8f00db | invalid byte sequence for encoding "SHIFT_JIS_2004": 0x8f 0x00
+ invalid, NUL byte                     | \x666f6f8fdb00 | \x666f6fbedd | \x00     | invalid byte sequence for encoding "SHIFT_JIS_2004": 0x00
+(9 rows)
+
+--
+-- GB18030
+--
+CREATE TABLE gb18030_inputs (inbytes bytea, description text);
+insert into gb18030_inputs  values
+  ('\x666f6f',		'valid, pure ASCII'),
+  ('\x666f6fcff3',	'valid'),
+  ('\x666f6f8431a530',	'valid, no translation to UTF-8'),
+  ('\x666f6f84309c38',	'valid, translates to UTF-8 by mapping function'),
+  ('\x666f6f84309c',	'incomplete char '),
+  ('\x666f6f84309c0a',	'incomplete char, followed by newline '),
+  ('\x666f6f84309c3800', 'invalid, NUL byte'),
+  ('\x666f6f84309c0038', 'invalid, NUL byte');
+-- Test GB18030 verification
+select description, inbytes, (test_conv(inbytes, 'gb18030', 'gb18030')).* from gb18030_inputs;
+                  description                   |      inbytes       |      result      |   errorat    |                               error                               
+------------------------------------------------+--------------------+------------------+--------------+-------------------------------------------------------------------
+ valid, pure ASCII                              | \x666f6f           | \x666f6f         |              | 
+ valid                                          | \x666f6fcff3       | \x666f6fcff3     |              | 
+ valid, no translation to UTF-8                 | \x666f6f8431a530   | \x666f6f8431a530 |              | 
+ valid, translates to UTF-8 by mapping function | \x666f6f84309c38   | \x666f6f84309c38 |              | 
+ incomplete char                                | \x666f6f84309c     | \x666f6f         | \x84309c     | invalid byte sequence for encoding "GB18030": 0x84 0x30 0x9c
+ incomplete char, followed by newline           | \x666f6f84309c0a   | \x666f6f         | \x84309c0a   | invalid byte sequence for encoding "GB18030": 0x84 0x30 0x9c 0x0a
+ invalid, NUL byte                              | \x666f6f84309c3800 | \x666f6f84309c38 | \x00         | invalid byte sequence for encoding "GB18030": 0x00
+ invalid, NUL byte                              | \x666f6f84309c0038 | \x666f6f         | \x84309c0038 | invalid byte sequence for encoding "GB18030": 0x84 0x30 0x9c 0x00
+(8 rows)
+
+-- Test conversions from GB18030
+select description, inbytes, (test_conv(inbytes, 'gb18030', 'utf8')).* from gb18030_inputs;
+                  description                   |      inbytes       |     result     |   errorat    |                                                    error                                                    
+------------------------------------------------+--------------------+----------------+--------------+-------------------------------------------------------------------------------------------------------------
+ valid, pure ASCII                              | \x666f6f           | \x666f6f       |              | 
+ valid                                          | \x666f6fcff3       | \x666f6fe8b1a1 |              | 
+ valid, no translation to UTF-8                 | \x666f6f8431a530   | \x666f6f       | \x8431a530   | character with byte sequence 0x84 0x31 0xa5 0x30 in encoding "GB18030" has no equivalent in encoding "UTF8"
+ valid, translates to UTF-8 by mapping function | \x666f6f84309c38   | \x666f6fefa8aa |              | 
+ incomplete char                                | \x666f6f84309c     | \x666f6f       | \x84309c     | invalid byte sequence for encoding "GB18030": 0x84 0x30 0x9c
+ incomplete char, followed by newline           | \x666f6f84309c0a   | \x666f6f       | \x84309c0a   | invalid byte sequence for encoding "GB18030": 0x84 0x30 0x9c 0x0a
+ invalid, NUL byte                              | \x666f6f84309c3800 | \x666f6fefa8aa | \x00         | invalid byte sequence for encoding "GB18030": 0x00
+ invalid, NUL byte                              | \x666f6f84309c0038 | \x666f6f       | \x84309c0038 | invalid byte sequence for encoding "GB18030": 0x84 0x30 0x9c 0x00
+(8 rows)
+
+--
+-- ISO-8859-5
+--
+CREATE TABLE iso8859_5_inputs (inbytes bytea, description text);
+insert into iso8859_5_inputs  values
+  ('\x666f6f',		'valid, pure ASCII'),
+  ('\xe4dede',		'valid'),
+  ('\x00',		'invalid, NUL byte'),
+  ('\xe400dede',	'invalid, NUL byte'),
+  ('\xe4dede00',	'invalid, NUL byte');
+-- Test ISO-8859-5 verification
+select description, inbytes, (test_conv(inbytes, 'iso8859-5', 'iso8859-5')).* from iso8859_5_inputs;
+    description    |  inbytes   |  result  | errorat  |                         error                         
+-------------------+------------+----------+----------+-------------------------------------------------------
+ valid, pure ASCII | \x666f6f   | \x666f6f |          | 
+ valid             | \xe4dede   | \xe4dede |          | 
+ invalid, NUL byte | \x00       | \x       | \x00     | invalid byte sequence for encoding "ISO_8859_5": 0x00
+ invalid, NUL byte | \xe400dede | \xe4     | \x00dede | invalid byte sequence for encoding "ISO_8859_5": 0x00
+ invalid, NUL byte | \xe4dede00 | \xe4dede | \x00     | invalid byte sequence for encoding "ISO_8859_5": 0x00
+(5 rows)
+
+-- Test conversions from ISO-8859-5
+select description, inbytes, (test_conv(inbytes, 'iso8859-5', 'utf8')).* from iso8859_5_inputs;
+    description    |  inbytes   |     result     | errorat  |                         error                         
+-------------------+------------+----------------+----------+-------------------------------------------------------
+ valid, pure ASCII | \x666f6f   | \x666f6f       |          | 
+ valid             | \xe4dede   | \xd184d0bed0be |          | 
+ invalid, NUL byte | \x00       | \x             | \x00     | invalid byte sequence for encoding "ISO_8859_5": 0x00
+ invalid, NUL byte | \xe400dede | \xd184         | \x00dede | invalid byte sequence for encoding "ISO_8859_5": 0x00
+ invalid, NUL byte | \xe4dede00 | \xd184d0bed0be | \x00     | invalid byte sequence for encoding "ISO_8859_5": 0x00
+(5 rows)
+
+select description, inbytes, (test_conv(inbytes, 'iso8859-5', 'koi8r')).* from iso8859_5_inputs;
+    description    |  inbytes   |  result  | errorat  |                         error                         
+-------------------+------------+----------+----------+-------------------------------------------------------
+ valid, pure ASCII | \x666f6f   | \x666f6f |          | 
+ valid             | \xe4dede   | \xc6cfcf |          | 
+ invalid, NUL byte | \x00       | \x       | \x00     | invalid byte sequence for encoding "ISO_8859_5": 0x00
+ invalid, NUL byte | \xe400dede | \xc6     | \x00dede | invalid byte sequence for encoding "ISO_8859_5": 0x00
+ invalid, NUL byte | \xe4dede00 | \xc6cfcf | \x00     | invalid byte sequence for encoding "ISO_8859_5": 0x00
+(5 rows)
+
+select description, inbytes, (test_conv(inbytes, 'iso8859_5', 'mule_internal')).* from iso8859_5_inputs;
+    description    |  inbytes   |     result     | errorat  |                         error                         
+-------------------+------------+----------------+----------+-------------------------------------------------------
+ valid, pure ASCII | \x666f6f   | \x666f6f       |          | 
+ valid             | \xe4dede   | \x8bc68bcf8bcf |          | 
+ invalid, NUL byte | \x00       | \x             | \x00     | invalid byte sequence for encoding "ISO_8859_5": 0x00
+ invalid, NUL byte | \xe400dede | \x8bc6         | \x00dede | invalid byte sequence for encoding "ISO_8859_5": 0x00
+ invalid, NUL byte | \xe4dede00 | \x8bc68bcf8bcf | \x00     | invalid byte sequence for encoding "ISO_8859_5": 0x00
+(5 rows)
+
+--
+-- Big5
+--
+CREATE TABLE big5_inputs (inbytes bytea, description text);
+insert into big5_inputs  values
+  ('\x666f6f',		'valid, pure ASCII'),
+  ('\x666f6fb648',	'valid'),
+  ('\x666f6fa27f',	'valid, no translation to UTF-8'),
+  ('\x666f6fb60048',	'invalid, NUL byte'),
+  ('\x666f6fb64800',	'invalid, NUL byte');
+-- Test Big5 verification
+select description, inbytes, (test_conv(inbytes, 'big5', 'big5')).* from big5_inputs;
+          description           |    inbytes     |    result    | errorat  |                        error                         
+--------------------------------+----------------+--------------+----------+------------------------------------------------------
+ valid, pure ASCII              | \x666f6f       | \x666f6f     |          | 
+ valid                          | \x666f6fb648   | \x666f6fb648 |          | 
+ valid, no translation to UTF-8 | \x666f6fa27f   | \x666f6fa27f |          | 
+ invalid, NUL byte              | \x666f6fb60048 | \x666f6f     | \xb60048 | invalid byte sequence for encoding "BIG5": 0xb6 0x00
+ invalid, NUL byte              | \x666f6fb64800 | \x666f6fb648 | \x00     | invalid byte sequence for encoding "BIG5": 0x00
+(5 rows)
+
+-- Test conversions from Big5
+select description, inbytes, (test_conv(inbytes, 'big5', 'utf8')).* from big5_inputs;
+          description           |    inbytes     |     result     | errorat  |                                             error                                              
+--------------------------------+----------------+----------------+----------+------------------------------------------------------------------------------------------------
+ valid, pure ASCII              | \x666f6f       | \x666f6f       |          | 
+ valid                          | \x666f6fb648   | \x666f6fe8b1a1 |          | 
+ valid, no translation to UTF-8 | \x666f6fa27f   | \x666f6f       | \xa27f   | character with byte sequence 0xa2 0x7f in encoding "BIG5" has no equivalent in encoding "UTF8"
+ invalid, NUL byte              | \x666f6fb60048 | \x666f6f       | \xb60048 | invalid byte sequence for encoding "BIG5": 0xb6 0x00
+ invalid, NUL byte              | \x666f6fb64800 | \x666f6fe8b1a1 | \x00     | invalid byte sequence for encoding "BIG5": 0x00
+(5 rows)
+
+select description, inbytes, (test_conv(inbytes, 'big5', 'mule_internal')).* from big5_inputs;
+          description           |    inbytes     |     result     | errorat  |                        error                         
+--------------------------------+----------------+----------------+----------+------------------------------------------------------
+ valid, pure ASCII              | \x666f6f       | \x666f6f       |          | 
+ valid                          | \x666f6fb648   | \x666f6f95e2af |          | 
+ valid, no translation to UTF-8 | \x666f6fa27f   | \x666f6f95a3c1 |          | 
+ invalid, NUL byte              | \x666f6fb60048 | \x666f6f       | \xb60048 | invalid byte sequence for encoding "BIG5": 0xb6 0x00
+ invalid, NUL byte              | \x666f6fb64800 | \x666f6f95e2af | \x00     | invalid byte sequence for encoding "BIG5": 0x00
+(5 rows)
+
+--
+-- MULE_INTERNAL
+--
+CREATE TABLE mic_inputs (inbytes bytea, description text);
+insert into mic_inputs  values
+  ('\x666f6f',		'valid, pure ASCII'),
+  ('\x8bc68bcf8bcf',	'valid (in KOI8R)'),
+  ('\x8bc68bcf8b',	'invalid,incomplete char'),
+  ('\x92bedd',		'valid (in SHIFT_JIS)'),
+  ('\x92be',		'invalid, incomplete char)'),
+  ('\x666f6f95a3c1',	'valid (in Big5)'),
+  ('\x666f6f95a3',	'invalid, incomplete char'),
+  ('\x9200bedd',	'invalid, NUL byte'),
+  ('\x92bedd00',	'invalid, NUL byte'),
+  ('\x8b00c68bcf8bcf',	'invalid, NUL byte');
+-- Test MULE_INTERNAL verification
+select description, inbytes, (test_conv(inbytes, 'mule_internal', 'mule_internal')).* from mic_inputs;
+        description        |     inbytes      |     result     |     errorat      |                               error                                
+---------------------------+------------------+----------------+------------------+--------------------------------------------------------------------
+ valid, pure ASCII         | \x666f6f         | \x666f6f       |                  | 
+ valid (in KOI8R)          | \x8bc68bcf8bcf   | \x8bc68bcf8bcf |                  | 
+ invalid,incomplete char   | \x8bc68bcf8b     | \x8bc68bcf     | \x8b             | invalid byte sequence for encoding "MULE_INTERNAL": 0x8b
+ valid (in SHIFT_JIS)      | \x92bedd         | \x92bedd       |                  | 
+ invalid, incomplete char) | \x92be           | \x             | \x92be           | invalid byte sequence for encoding "MULE_INTERNAL": 0x92 0xbe
+ valid (in Big5)           | \x666f6f95a3c1   | \x666f6f95a3c1 |                  | 
+ invalid, incomplete char  | \x666f6f95a3     | \x666f6f       | \x95a3           | invalid byte sequence for encoding "MULE_INTERNAL": 0x95 0xa3
+ invalid, NUL byte         | \x9200bedd       | \x             | \x9200bedd       | invalid byte sequence for encoding "MULE_INTERNAL": 0x92 0x00 0xbe
+ invalid, NUL byte         | \x92bedd00       | \x92bedd       | \x00             | invalid byte sequence for encoding "MULE_INTERNAL": 0x00
+ invalid, NUL byte         | \x8b00c68bcf8bcf | \x             | \x8b00c68bcf8bcf | invalid byte sequence for encoding "MULE_INTERNAL": 0x8b 0x00
+(10 rows)
+
+-- Test conversions from MULE_INTERNAL
+select description, inbytes, (test_conv(inbytes, 'mule_internal', 'koi8r')).* from mic_inputs;
+        description        |     inbytes      |  result  |     errorat      |                                                     error                                                     
+---------------------------+------------------+----------+------------------+---------------------------------------------------------------------------------------------------------------
+ valid, pure ASCII         | \x666f6f         | \x666f6f |                  | 
+ valid (in KOI8R)          | \x8bc68bcf8bcf   | \xc6cfcf |                  | 
+ invalid,incomplete char   | \x8bc68bcf8b     | \xc6cf   | \x8b             | invalid byte sequence for encoding "MULE_INTERNAL": 0x8b
+ valid (in SHIFT_JIS)      | \x92bedd         | \x       | \x92bedd         | character with byte sequence 0x92 0xbe 0xdd in encoding "MULE_INTERNAL" has no equivalent in encoding "KOI8R"
+ invalid, incomplete char) | \x92be           | \x       | \x92be           | invalid byte sequence for encoding "MULE_INTERNAL": 0x92 0xbe
+ valid (in Big5)           | \x666f6f95a3c1   | \x666f6f | \x95a3c1         | character with byte sequence 0x95 0xa3 0xc1 in encoding "MULE_INTERNAL" has no equivalent in encoding "KOI8R"
+ invalid, incomplete char  | \x666f6f95a3     | \x666f6f | \x95a3           | invalid byte sequence for encoding "MULE_INTERNAL": 0x95 0xa3
+ invalid, NUL byte         | \x9200bedd       | \x       | \x9200bedd       | character with byte sequence 0x92 0x00 0xbe in encoding "MULE_INTERNAL" has no equivalent in encoding "KOI8R"
+ invalid, NUL byte         | \x92bedd00       | \x       | \x92bedd00       | character with byte sequence 0x92 0xbe 0xdd in encoding "MULE_INTERNAL" has no equivalent in encoding "KOI8R"
+ invalid, NUL byte         | \x8b00c68bcf8bcf | \x       | \x8b00c68bcf8bcf | character with byte sequence 0x8b 0x00 in encoding "MULE_INTERNAL" has no equivalent in encoding "KOI8R"
+(10 rows)
+
+select description, inbytes, (test_conv(inbytes, 'mule_internal', 'iso8859-5')).* from mic_inputs;
+        description        |     inbytes      |  result  |     errorat      |                                                       error                                                        
+---------------------------+------------------+----------+------------------+--------------------------------------------------------------------------------------------------------------------
+ valid, pure ASCII         | \x666f6f         | \x666f6f |                  | 
+ valid (in KOI8R)          | \x8bc68bcf8bcf   | \xe4dede |                  | 
+ invalid,incomplete char   | \x8bc68bcf8b     | \xe4de   | \x8b             | invalid byte sequence for encoding "MULE_INTERNAL": 0x8b
+ valid (in SHIFT_JIS)      | \x92bedd         | \x       | \x92bedd         | character with byte sequence 0x92 0xbe 0xdd in encoding "MULE_INTERNAL" has no equivalent in encoding "ISO_8859_5"
+ invalid, incomplete char) | \x92be           | \x       | \x92be           | invalid byte sequence for encoding "MULE_INTERNAL": 0x92 0xbe
+ valid (in Big5)           | \x666f6f95a3c1   | \x666f6f | \x95a3c1         | character with byte sequence 0x95 0xa3 0xc1 in encoding "MULE_INTERNAL" has no equivalent in encoding "ISO_8859_5"
+ invalid, incomplete char  | \x666f6f95a3     | \x666f6f | \x95a3           | invalid byte sequence for encoding "MULE_INTERNAL": 0x95 0xa3
+ invalid, NUL byte         | \x9200bedd       | \x       | \x9200bedd       | character with byte sequence 0x92 0x00 0xbe in encoding "MULE_INTERNAL" has no equivalent in encoding "ISO_8859_5"
+ invalid, NUL byte         | \x92bedd00       | \x       | \x92bedd00       | character with byte sequence 0x92 0xbe 0xdd in encoding "MULE_INTERNAL" has no equivalent in encoding "ISO_8859_5"
+ invalid, NUL byte         | \x8b00c68bcf8bcf | \x       | \x8b00c68bcf8bcf | character with byte sequence 0x8b 0x00 in encoding "MULE_INTERNAL" has no equivalent in encoding "ISO_8859_5"
+(10 rows)
+
+select description, inbytes, (test_conv(inbytes, 'mule_internal', 'sjis')).* from mic_inputs;
+        description        |     inbytes      |  result  |     errorat      |                                                    error                                                     
+---------------------------+------------------+----------+------------------+--------------------------------------------------------------------------------------------------------------
+ valid, pure ASCII         | \x666f6f         | \x666f6f |                  | 
+ valid (in KOI8R)          | \x8bc68bcf8bcf   | \x       | \x8bc68bcf8bcf   | character with byte sequence 0x8b 0xc6 in encoding "MULE_INTERNAL" has no equivalent in encoding "SJIS"
+ invalid,incomplete char   | \x8bc68bcf8b     | \x       | \x8bc68bcf8b     | character with byte sequence 0x8b 0xc6 in encoding "MULE_INTERNAL" has no equivalent in encoding "SJIS"
+ valid (in SHIFT_JIS)      | \x92bedd         | \x8fdb   |                  | 
+ invalid, incomplete char) | \x92be           | \x       | \x92be           | invalid byte sequence for encoding "MULE_INTERNAL": 0x92 0xbe
+ valid (in Big5)           | \x666f6f95a3c1   | \x666f6f | \x95a3c1         | character with byte sequence 0x95 0xa3 0xc1 in encoding "MULE_INTERNAL" has no equivalent in encoding "SJIS"
+ invalid, incomplete char  | \x666f6f95a3     | \x666f6f | \x95a3           | invalid byte sequence for encoding "MULE_INTERNAL": 0x95 0xa3
+ invalid, NUL byte         | \x9200bedd       | \x       | \x9200bedd       | invalid byte sequence for encoding "MULE_INTERNAL": 0x92 0x00 0xbe
+ invalid, NUL byte         | \x92bedd00       | \x8fdb   | \x00             | invalid byte sequence for encoding "MULE_INTERNAL": 0x00
+ invalid, NUL byte         | \x8b00c68bcf8bcf | \x       | \x8b00c68bcf8bcf | invalid byte sequence for encoding "MULE_INTERNAL": 0x8b 0x00
+(10 rows)
+
+select description, inbytes, (test_conv(inbytes, 'mule_internal', 'big5')).* from mic_inputs;
+        description        |     inbytes      |    result    |     errorat      |                                                    error                                                     
+---------------------------+------------------+--------------+------------------+--------------------------------------------------------------------------------------------------------------
+ valid, pure ASCII         | \x666f6f         | \x666f6f     |                  | 
+ valid (in KOI8R)          | \x8bc68bcf8bcf   | \x           | \x8bc68bcf8bcf   | character with byte sequence 0x8b 0xc6 in encoding "MULE_INTERNAL" has no equivalent in encoding "BIG5"
+ invalid,incomplete char   | \x8bc68bcf8b     | \x           | \x8bc68bcf8b     | character with byte sequence 0x8b 0xc6 in encoding "MULE_INTERNAL" has no equivalent in encoding "BIG5"
+ valid (in SHIFT_JIS)      | \x92bedd         | \x           | \x92bedd         | character with byte sequence 0x92 0xbe 0xdd in encoding "MULE_INTERNAL" has no equivalent in encoding "BIG5"
+ invalid, incomplete char) | \x92be           | \x           | \x92be           | invalid byte sequence for encoding "MULE_INTERNAL": 0x92 0xbe
+ valid (in Big5)           | \x666f6f95a3c1   | \x666f6fa2a1 |                  | 
+ invalid, incomplete char  | \x666f6f95a3     | \x666f6f     | \x95a3           | invalid byte sequence for encoding "MULE_INTERNAL": 0x95 0xa3
+ invalid, NUL byte         | \x9200bedd       | \x           | \x9200bedd       | invalid byte sequence for encoding "MULE_INTERNAL": 0x92 0x00 0xbe
+ invalid, NUL byte         | \x92bedd00       | \x           | \x92bedd00       | character with byte sequence 0x92 0xbe 0xdd in encoding "MULE_INTERNAL" has no equivalent in encoding "BIG5"
+ invalid, NUL byte         | \x8b00c68bcf8bcf | \x           | \x8b00c68bcf8bcf | invalid byte sequence for encoding "MULE_INTERNAL": 0x8b 0x00
+(10 rows)
+
+select description, inbytes, (test_conv(inbytes, 'mule_internal', 'euc_jp')).* from mic_inputs;
+        description        |     inbytes      |  result  |     errorat      |                                                     error                                                      
+---------------------------+------------------+----------+------------------+----------------------------------------------------------------------------------------------------------------
+ valid, pure ASCII         | \x666f6f         | \x666f6f |                  | 
+ valid (in KOI8R)          | \x8bc68bcf8bcf   | \x       | \x8bc68bcf8bcf   | character with byte sequence 0x8b 0xc6 in encoding "MULE_INTERNAL" has no equivalent in encoding "EUC_JP"
+ invalid,incomplete char   | \x8bc68bcf8b     | \x       | \x8bc68bcf8b     | character with byte sequence 0x8b 0xc6 in encoding "MULE_INTERNAL" has no equivalent in encoding "EUC_JP"
+ valid (in SHIFT_JIS)      | \x92bedd         | \xbedd   |                  | 
+ invalid, incomplete char) | \x92be           | \x       | \x92be           | invalid byte sequence for encoding "MULE_INTERNAL": 0x92 0xbe
+ valid (in Big5)           | \x666f6f95a3c1   | \x666f6f | \x95a3c1         | character with byte sequence 0x95 0xa3 0xc1 in encoding "MULE_INTERNAL" has no equivalent in encoding "EUC_JP"
+ invalid, incomplete char  | \x666f6f95a3     | \x666f6f | \x95a3           | invalid byte sequence for encoding "MULE_INTERNAL": 0x95 0xa3
+ invalid, NUL byte         | \x9200bedd       | \x       | \x9200bedd       | invalid byte sequence for encoding "MULE_INTERNAL": 0x92 0x00 0xbe
+ invalid, NUL byte         | \x92bedd00       | \xbedd   | \x00             | invalid byte sequence for encoding "MULE_INTERNAL": 0x00
+ invalid, NUL byte         | \x8b00c68bcf8bcf | \x       | \x8b00c68bcf8bcf | invalid byte sequence for encoding "MULE_INTERNAL": 0x8b 0x00
+(10 rows)
+
diff --git a/src/test/regress/expected/opr_sanity.out b/src/test/regress/expected/opr_sanity.out
index ef4b4444b90..fa26bf76104 100644
--- a/src/test/regress/expected/opr_sanity.out
+++ b/src/test/regress/expected/opr_sanity.out
@@ -1052,13 +1052,14 @@ WHERE p1.conproc = 0 OR
 SELECT p.oid, p.proname, c.oid, c.conname
 FROM pg_proc p, pg_conversion c
 WHERE p.oid = c.conproc AND
-    (p.prorettype != 'void'::regtype OR p.proretset OR
-     p.pronargs != 5 OR
+    (p.prorettype != 'int4'::regtype OR p.proretset OR
+     p.pronargs != 6 OR
      p.proargtypes[0] != 'int4'::regtype OR
      p.proargtypes[1] != 'int4'::regtype OR
      p.proargtypes[2] != 'cstring'::regtype OR
      p.proargtypes[3] != 'internal'::regtype OR
-     p.proargtypes[4] != 'int4'::regtype);
+     p.proargtypes[4] != 'int4'::regtype OR
+     p.proargtypes[5] != 'bool'::regtype);
  oid | proname | oid | conname 
 -----+---------+-----+---------
 (0 rows)
diff --git a/src/test/regress/input/create_function_1.source b/src/test/regress/input/create_function_1.source
index 412e339fcf2..6ba37fe63b6 100644
--- a/src/test/regress/input/create_function_1.source
+++ b/src/test/regress/input/create_function_1.source
@@ -78,6 +78,10 @@ CREATE FUNCTION test_opclass_options_func(internal)
     AS '@libdir@/regress@DLSUFFIX@', 'test_opclass_options_func'
     LANGUAGE C;
 
+CREATE FUNCTION test_enc_conversion(bytea, name, name, bool, validlen OUT int, result OUT bytea)
+    AS '@libdir@/regress@DLSUFFIX@', 'test_enc_conversion'
+    LANGUAGE C;
+
 -- Things that shouldn't work:
 
 CREATE FUNCTION test1 (int) RETURNS int LANGUAGE SQL
diff --git a/src/test/regress/output/create_function_1.source b/src/test/regress/output/create_function_1.source
index 4d78fa12289..cb38a039bf4 100644
--- a/src/test/regress/output/create_function_1.source
+++ b/src/test/regress/output/create_function_1.source
@@ -68,6 +68,9 @@ CREATE FUNCTION test_opclass_options_func(internal)
     RETURNS void
     AS '@libdir@/regress@DLSUFFIX@', 'test_opclass_options_func'
     LANGUAGE C;
+CREATE FUNCTION test_enc_conversion(bytea, name, name, bool, validlen OUT int, result OUT bytea)
+    AS '@libdir@/regress@DLSUFFIX@', 'test_enc_conversion'
+    LANGUAGE C;
 -- Things that shouldn't work:
 CREATE FUNCTION test1 (int) RETURNS int LANGUAGE SQL
     AS 'SELECT ''not an integer'';';
diff --git a/src/test/regress/regress.c b/src/test/regress/regress.c
index 32ab9ed6b53..1990cbb6a13 100644
--- a/src/test/regress/regress.c
+++ b/src/test/regress/regress.c
@@ -23,12 +23,15 @@
 #include "access/htup_details.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/namespace.h"
 #include "catalog/pg_operator.h"
 #include "catalog/pg_type.h"
 #include "commands/sequence.h"
 #include "commands/trigger.h"
 #include "executor/executor.h"
 #include "executor/spi.h"
+#include "funcapi.h"
+#include "mb/pg_wchar.h"
 #include "miscadmin.h"
 #include "nodes/supportnodes.h"
 #include "optimizer/optimizer.h"
@@ -1060,3 +1063,134 @@ test_opclass_options_func(PG_FUNCTION_ARGS)
 {
 	PG_RETURN_NULL();
 }
+
+/*
+ * Call an encoding conversion or verification function.
+ *
+ * Arguments:
+ *	string	  bytea -- string to convert
+ *	src_enc	  name  -- source encoding
+ *	dest_enc  name  -- destination encoding
+ *	noError	  bool  -- if set, don't ereport() on invalid or untranslatable
+ *					   input
+ *
+ * Result is a tuple with two attributes:
+ *  int4	-- number of input bytes successfully converted
+ *  bytea	-- converted string
+ */
+PG_FUNCTION_INFO_V1(test_enc_conversion);
+Datum
+test_enc_conversion(PG_FUNCTION_ARGS)
+{
+	bytea	   *string = PG_GETARG_BYTEA_PP(0);
+	char	   *src_encoding_name = NameStr(*PG_GETARG_NAME(1));
+	int			src_encoding = pg_char_to_encoding(src_encoding_name);
+	char	   *dest_encoding_name = NameStr(*PG_GETARG_NAME(2));
+	int			dest_encoding = pg_char_to_encoding(dest_encoding_name);
+	bool		noError = PG_GETARG_BOOL(3);
+	TupleDesc	tupdesc;
+	char	   *src;
+	char	   *dst;
+	bytea	   *retval;
+	Size		srclen;
+	Size		dstsize;
+	Oid			proc;
+	int			convertedbytes;
+	int			dstlen;
+	Datum		values[2];
+	bool		nulls[2];
+	HeapTuple	tuple;
+
+	if (src_encoding < 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("invalid source encoding name \"%s\"",
+						src_encoding_name)));
+	if (dest_encoding < 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("invalid destination encoding name \"%s\"",
+						dest_encoding_name)));
+
+	/* Build a tuple descriptor for our result type */
+	if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
+		elog(ERROR, "return type must be a row type");
+	tupdesc = BlessTupleDesc(tupdesc);
+
+	srclen = VARSIZE_ANY_EXHDR(string);
+	src = VARDATA_ANY(string);
+
+	if (src_encoding == dest_encoding)
+	{
+		/* just check that the source string is valid */
+		int			oklen;
+
+		oklen = pg_encoding_verifymbstr(src_encoding, src, srclen);
+
+		if (oklen == srclen)
+		{
+			convertedbytes = oklen;
+			retval = string;
+		}
+		else if (!noError)
+		{
+			report_invalid_encoding(src_encoding, src + oklen, srclen - oklen);
+		}
+		else
+		{
+			/*
+			 * build bytea data type structure.
+			 */
+			Assert(oklen < srclen);
+			convertedbytes = oklen;
+			retval = (bytea *) palloc(oklen + VARHDRSZ);
+			SET_VARSIZE(retval, oklen + VARHDRSZ);
+			memcpy(VARDATA(retval), src, oklen);
+		}
+	}
+	else
+	{
+		proc = FindDefaultConversionProc(src_encoding, dest_encoding);
+		if (!OidIsValid(proc))
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_FUNCTION),
+					 errmsg("default conversion function for encoding \"%s\" to \"%s\" does not exist",
+							pg_encoding_to_char(src_encoding),
+							pg_encoding_to_char(dest_encoding))));
+
+		if (srclen >= (MaxAllocSize / (Size) MAX_CONVERSION_GROWTH))
+			ereport(ERROR,
+					(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
+					 errmsg("out of memory"),
+					 errdetail("String of %d bytes is too long for encoding conversion.",
+							   (int) srclen)));
+
+		dstsize = (Size) srclen * MAX_CONVERSION_GROWTH + 1;
+		dst = MemoryContextAlloc(CurrentMemoryContext, dstsize);
+
+		/* perform conversion */
+		convertedbytes = pg_do_encoding_conversion_buf(proc,
+													   src_encoding,
+													   dest_encoding,
+													   (unsigned char *) src, srclen,
+													   (unsigned char *) dst, dstsize,
+													   noError);
+		dstlen = strlen(dst);
+
+		/*
+		 * build bytea data type structure.
+		 */
+		retval = (bytea *) palloc(dstlen + VARHDRSZ);
+		SET_VARSIZE(retval, dstlen + VARHDRSZ);
+		memcpy(VARDATA(retval), dst, dstlen);
+
+		pfree(dst);
+	}
+
+	MemSet(nulls, 0, sizeof(nulls));
+	values[0] = Int32GetDatum(convertedbytes);
+	values[1] = PointerGetDatum(retval);
+	tuple = heap_form_tuple(tupdesc, values, nulls);
+
+	PG_RETURN_DATUM(HeapTupleGetDatum(tuple));
+}
diff --git a/src/test/regress/sql/conversion.sql b/src/test/regress/sql/conversion.sql
index 02cf39f1ce9..ea85f20ed83 100644
--- a/src/test/regress/sql/conversion.sql
+++ b/src/test/regress/sql/conversion.sql
@@ -34,3 +34,188 @@ DROP CONVERSION mydef;
 --
 RESET SESSION AUTHORIZATION;
 DROP USER regress_conversion_user;
+
+--
+-- Test built-in conversion functions.
+--
+
+-- Helper function to test a conversion. Uses the test_enc_conversion function
+-- that was created in the create_function_1 test.
+create or replace function test_conv(
+  input IN bytea,
+  src_encoding IN text,
+  dst_encoding IN text,
+
+  result OUT bytea,
+  errorat OUT bytea,
+  error OUT text)
+language plpgsql as
+$$
+declare
+  validlen int;
+begin
+  -- First try to perform the conversion with noError = false. If that errors out,
+  -- capture the error message, and try again with noError = true. The second call
+  -- should succeed and return the position of the error, return that too.
+  begin
+    select * into validlen, result from test_enc_conversion(input, src_encoding, dst_encoding, false);
+    errorat = NULL;
+    error := NULL;
+  exception when others then
+    error := sqlerrm;
+    select * into validlen, result from test_enc_conversion(input, src_encoding, dst_encoding, true);
+    errorat = substr(input, validlen + 1);
+  end;
+  return;
+end;
+$$;
+
+
+--
+-- UTF-8
+--
+CREATE TABLE utf8_inputs (inbytes bytea, description text);
+insert into utf8_inputs  values
+  ('\x666f6f',		'valid, pure ASCII'),
+  ('\xc3a4c3b6',	'valid, extra latin chars'),
+  ('\xd184d0bed0be',	'valid, cyrillic'),
+  ('\x666f6fe8b1a1',	'valid, kanji/Chinese'),
+  ('\xe382abe3829a',	'valid, two chars that combine to one in EUC_JIS_2004'),
+  ('\xe382ab',		'only first half of combined char in EUC_JIS_2004'),
+  ('\xe382abe382',	'incomplete combination when converted EUC_JIS_2004'),
+  ('\xecbd94eb81bceba6ac', 'valid, Hangul, Korean'),
+  ('\x666f6fefa8aa',	'valid, needs mapping function to convert to GB18030'),
+  ('\x66e8b1ff6f6f',	'invalid byte sequence'),
+  ('\x66006f',		'invalid, NUL byte'),
+  ('\x666f6fe8b100',	'invalid, NUL byte'),
+  ('\x666f6fe8b1',	'incomplete character at end');
+
+-- Test UTF-8 verification
+select description, (test_conv(inbytes, 'utf8', 'utf8')).* from utf8_inputs;
+-- Test conversions from UTF-8
+select description, inbytes, (test_conv(inbytes, 'utf8', 'euc_jis_2004')).* from utf8_inputs;
+select description, inbytes, (test_conv(inbytes, 'utf8', 'latin1')).* from utf8_inputs;
+select description, inbytes, (test_conv(inbytes, 'utf8', 'latin2')).* from utf8_inputs;
+select description, inbytes, (test_conv(inbytes, 'utf8', 'latin5')).* from utf8_inputs;
+select description, inbytes, (test_conv(inbytes, 'utf8', 'koi8r')).* from utf8_inputs;
+select description, inbytes, (test_conv(inbytes, 'utf8', 'gb18030')).* from utf8_inputs;
+
+--
+-- EUC_JIS_2004
+--
+CREATE TABLE euc_jis_2004_inputs (inbytes bytea, description text);
+insert into euc_jis_2004_inputs  values
+  ('\x666f6f',		'valid, pure ASCII'),
+  ('\x666f6fbedd',	'valid'),
+  ('\xa5f7',		'valid, translates to two UTF-8 chars '),
+  ('\xbeddbe',		'incomplete char '),
+  ('\x666f6f00bedd',	'invalid, NUL byte'),
+  ('\x666f6fbe00dd',	'invalid, NUL byte'),
+  ('\x666f6fbedd00',	'invalid, NUL byte'),
+  ('\xbe04',		'invalid byte sequence');
+
+-- Test EUC_JIS_2004 verification
+select description, inbytes, (test_conv(inbytes, 'euc_jis_2004', 'euc_jis_2004')).* from euc_jis_2004_inputs;
+-- Test conversions from EUC_JIS_2004
+select description, inbytes, (test_conv(inbytes, 'euc_jis_2004', 'utf8')).* from euc_jis_2004_inputs;
+
+--
+-- SHIFT-JIS-2004
+--
+CREATE TABLE shiftjis2004_inputs (inbytes bytea, description text);
+insert into shiftjis2004_inputs  values
+  ('\x666f6f',		'valid, pure ASCII'),
+  ('\x666f6f8fdb',	'valid'),
+  ('\x666f6f81c0',	'valid, no translation to UTF-8'),
+  ('\x666f6f82f5',	'valid, translates to two UTF-8 chars '),
+  ('\x666f6f8fdb8f',	'incomplete char '),
+  ('\x666f6f820a',	'incomplete char, followed by newline '),
+  ('\x666f6f008fdb',	'invalid, NUL byte'),
+  ('\x666f6f8f00db',	'invalid, NUL byte'),
+  ('\x666f6f8fdb00',	'invalid, NUL byte');
+
+-- Test SHIFT-JIS-2004 verification
+select description, inbytes, (test_conv(inbytes, 'shiftjis2004', 'shiftjis2004')).* from shiftjis2004_inputs;
+-- Test conversions from SHIFT-JIS-2004
+select description, inbytes, (test_conv(inbytes, 'shiftjis2004', 'utf8')).* from shiftjis2004_inputs;
+select description, inbytes, (test_conv(inbytes, 'shiftjis2004', 'euc_jis_2004')).* from shiftjis2004_inputs;
+
+--
+-- GB18030
+--
+CREATE TABLE gb18030_inputs (inbytes bytea, description text);
+insert into gb18030_inputs  values
+  ('\x666f6f',		'valid, pure ASCII'),
+  ('\x666f6fcff3',	'valid'),
+  ('\x666f6f8431a530',	'valid, no translation to UTF-8'),
+  ('\x666f6f84309c38',	'valid, translates to UTF-8 by mapping function'),
+  ('\x666f6f84309c',	'incomplete char '),
+  ('\x666f6f84309c0a',	'incomplete char, followed by newline '),
+  ('\x666f6f84309c3800', 'invalid, NUL byte'),
+  ('\x666f6f84309c0038', 'invalid, NUL byte');
+
+-- Test GB18030 verification
+select description, inbytes, (test_conv(inbytes, 'gb18030', 'gb18030')).* from gb18030_inputs;
+-- Test conversions from GB18030
+select description, inbytes, (test_conv(inbytes, 'gb18030', 'utf8')).* from gb18030_inputs;
+
+
+--
+-- ISO-8859-5
+--
+CREATE TABLE iso8859_5_inputs (inbytes bytea, description text);
+insert into iso8859_5_inputs  values
+  ('\x666f6f',		'valid, pure ASCII'),
+  ('\xe4dede',		'valid'),
+  ('\x00',		'invalid, NUL byte'),
+  ('\xe400dede',	'invalid, NUL byte'),
+  ('\xe4dede00',	'invalid, NUL byte');
+
+-- Test ISO-8859-5 verification
+select description, inbytes, (test_conv(inbytes, 'iso8859-5', 'iso8859-5')).* from iso8859_5_inputs;
+-- Test conversions from ISO-8859-5
+select description, inbytes, (test_conv(inbytes, 'iso8859-5', 'utf8')).* from iso8859_5_inputs;
+select description, inbytes, (test_conv(inbytes, 'iso8859-5', 'koi8r')).* from iso8859_5_inputs;
+select description, inbytes, (test_conv(inbytes, 'iso8859_5', 'mule_internal')).* from iso8859_5_inputs;
+
+--
+-- Big5
+--
+CREATE TABLE big5_inputs (inbytes bytea, description text);
+insert into big5_inputs  values
+  ('\x666f6f',		'valid, pure ASCII'),
+  ('\x666f6fb648',	'valid'),
+  ('\x666f6fa27f',	'valid, no translation to UTF-8'),
+  ('\x666f6fb60048',	'invalid, NUL byte'),
+  ('\x666f6fb64800',	'invalid, NUL byte');
+
+-- Test Big5 verification
+select description, inbytes, (test_conv(inbytes, 'big5', 'big5')).* from big5_inputs;
+-- Test conversions from Big5
+select description, inbytes, (test_conv(inbytes, 'big5', 'utf8')).* from big5_inputs;
+select description, inbytes, (test_conv(inbytes, 'big5', 'mule_internal')).* from big5_inputs;
+
+--
+-- MULE_INTERNAL
+--
+CREATE TABLE mic_inputs (inbytes bytea, description text);
+insert into mic_inputs  values
+  ('\x666f6f',		'valid, pure ASCII'),
+  ('\x8bc68bcf8bcf',	'valid (in KOI8R)'),
+  ('\x8bc68bcf8b',	'invalid,incomplete char'),
+  ('\x92bedd',		'valid (in SHIFT_JIS)'),
+  ('\x92be',		'invalid, incomplete char)'),
+  ('\x666f6f95a3c1',	'valid (in Big5)'),
+  ('\x666f6f95a3',	'invalid, incomplete char'),
+  ('\x9200bedd',	'invalid, NUL byte'),
+  ('\x92bedd00',	'invalid, NUL byte'),
+  ('\x8b00c68bcf8bcf',	'invalid, NUL byte');
+
+-- Test MULE_INTERNAL verification
+select description, inbytes, (test_conv(inbytes, 'mule_internal', 'mule_internal')).* from mic_inputs;
+-- Test conversions from MULE_INTERNAL
+select description, inbytes, (test_conv(inbytes, 'mule_internal', 'koi8r')).* from mic_inputs;
+select description, inbytes, (test_conv(inbytes, 'mule_internal', 'iso8859-5')).* from mic_inputs;
+select description, inbytes, (test_conv(inbytes, 'mule_internal', 'sjis')).* from mic_inputs;
+select description, inbytes, (test_conv(inbytes, 'mule_internal', 'big5')).* from mic_inputs;
+select description, inbytes, (test_conv(inbytes, 'mule_internal', 'euc_jp')).* from mic_inputs;
diff --git a/src/test/regress/sql/opr_sanity.sql b/src/test/regress/sql/opr_sanity.sql
index bbd3834b634..04691745981 100644
--- a/src/test/regress/sql/opr_sanity.sql
+++ b/src/test/regress/sql/opr_sanity.sql
@@ -556,13 +556,14 @@ WHERE p1.conproc = 0 OR
 SELECT p.oid, p.proname, c.oid, c.conname
 FROM pg_proc p, pg_conversion c
 WHERE p.oid = c.conproc AND
-    (p.prorettype != 'void'::regtype OR p.proretset OR
-     p.pronargs != 5 OR
+    (p.prorettype != 'int4'::regtype OR p.proretset OR
+     p.pronargs != 6 OR
      p.proargtypes[0] != 'int4'::regtype OR
      p.proargtypes[1] != 'int4'::regtype OR
      p.proargtypes[2] != 'cstring'::regtype OR
      p.proargtypes[3] != 'internal'::regtype OR
-     p.proargtypes[4] != 'int4'::regtype);
+     p.proargtypes[4] != 'int4'::regtype OR
+     p.proargtypes[5] != 'bool'::regtype);
 
 -- Check for conprocs that don't perform the specific conversion that
 -- pg_conversion alleges they do, by trying to invoke each conversion