I really hope that I haven't missed anything in this one...

From: t-ishii@sra.co.jp

Attached are patches to enhance the multi-byte support.  (patches are
against 7/18 snapshot)

* determine encoding at initdb/createdb rather than compile time

Now initdb/createdb has an option to specify the encoding. Also, I
modified the syntax of CREATE DATABASE to accept encoding option. See
README.mb for more details.

For this purpose I have added new column "encoding" to pg_database.
Also pg_attribute and pg_class are changed to catch up the
modification to pg_database.  Actually I haved added pg_database_mb.h,
pg_attribute_mb.h and pg_class_mb.h. These are used only when MB is
enabled. The reason having separate files is I couldn't find a way to
use ifdef or whatever in those files. I have to admit it looks
ugly. No way.

* support for PGCLIENTENCODING when issuing COPY command

commands/copy.c modified.

* support for SQL92 syntax "SET NAMES"

See gram.y.

* support for LATIN2-5
* add UNICODE regression test case
* new test suite for MB

New directory test/mb added.

* clean up source files

Basic idea is to have MB's own subdirectory for easier maintenance.
These are include/mb and backend/utils/mb.

src/backend/utils/mb/wchar.c

@@ -0,0 +1,358 @@
+/*
+ * conversion functions between pg_wchar and multi-byte streams.
+ * Tatsuo Ishii
+ * $Id: wchar.c,v 1.1 1998/07/24 03:31:57 scrappy Exp $
+ */
+
+#include "mb/pg_wchar.h"
+
+/*
+ * conversion to pg_wchar is done by "table driven."
+ * to add an encoding support, define mb2wchar_with_len(), mblen()
+ * for the particular encoding. Note that if the encoding is only
+ * supported in the client, you don't need to define 
+ * mb2wchar_with_len() function (SJIS is the case).
+ */
+static void pg_euc2wchar_with_len
+(const unsigned char *from, pg_wchar *to, int len)
+{
+  while (*from && len > 0) {
+    if (*from == SS2) {
+      from++;
+      len--;
+      *to = 0xff & *from++;
+      len--;
+    } else if (*from == SS3) {
+      from++;
+      *to = *from++ << 8;
+      *to |= 0x3f & *from++;
+      len -= 3;
+    } else if (*from & 0x80) {
+      *to = *from++ << 8;
+      *to |= *from++;
+      len -= 2;
+    } else {
+      *to = *from++;
+      len--;
+    }
+    to++;
+  }
+  *to = 0;
+}
+
+static int pg_euc_mblen(const unsigned char *s)
+{
+  int len;
+
+  if (*s == SS2) {
+    len = 2;
+  } else if (*s == SS3) {
+    len = 3;
+  } else if (*s & 0x80) {
+    len = 2;
+  } else {
+    len = 1;
+  }
+  return(len);
+}
+
+/*
+ * EUC_JP
+ */
+static void pg_eucjp2wchar_with_len
+(const unsigned char *from, pg_wchar *to, int len)
+{
+  pg_euc2wchar_with_len(from,to,len);
+}
+
+static int pg_eucjp_mblen(const unsigned char *s)
+{
+  return(pg_euc_mblen(s));
+}
+
+/*
+ * EUC_KR
+ */
+static void pg_euckr2wchar_with_len
+(const unsigned char *from, pg_wchar *to, int len)
+{
+  pg_euc2wchar_with_len(from,to,len);
+}
+
+static int pg_euckr_mblen(const unsigned char *s)
+{
+  return(pg_euc_mblen(s));
+}
+
+/*
+ * EUC_CN
+ */
+static void pg_euccn2wchar_with_len
+(const unsigned char *from, pg_wchar *to, int len)
+{
+  while (*from && len > 0) {
+    if (*from == SS2) {
+      from++;
+      len--;
+      *to = 0x3f00 & (*from++ << 8);
+      *to = *from++;
+      len -= 2;
+    } else if (*from == SS3) {
+      from++;
+      *to = *from++ << 8;
+      *to |= 0x3f & *from++;
+      len -= 3;
+    } else if (*from & 0x80) {
+      *to = *from++ << 8;
+      *to |= *from++;
+      len -= 2;
+    } else {
+      *to = *from++;
+      len--;
+    }
+    to++;
+  }
+  *to = 0;
+}
+
+static int pg_euccn_mblen(const unsigned char *s)
+{
+  int len;
+
+  if (*s == SS2) {
+    len = 3;
+  } else if (*s == SS3) {
+    len = 3;
+  } else if (*s & 0x80) {
+    len = 2;
+  } else {
+    len = 1;
+  }
+  return(len);
+}
+
+/*
+ * EUC_TW
+ */
+static void pg_euctw2wchar_with_len
+(const unsigned char *from, pg_wchar *to, int len)
+{
+  while (*from && len > 0) {
+    if (*from == SS2) {
+      from++;
+      len--;
+      *to = *from++ << 16;
+      *to |= *from++ << 8;
+      *to |= *from++;
+      len -= 3;
+    } else if (*from == SS3) {
+      from++;
+      *to = *from++ << 8;
+      *to |= 0x3f & *from++;
+      len -= 3;
+    } else if (*from & 0x80) {
+      *to = *from++ << 8;
+      *to |= *from++;
+      len -= 2;
+    } else {
+      *to = *from++;
+      len--;
+    }
+    to++;
+  }
+  *to = 0;
+}
+
+static int pg_euctw_mblen(const unsigned char *s)
+{
+  int len;
+
+  if (*s == SS2) {
+    len = 4;
+  } else if (*s == SS3) {
+    len = 3;
+  } else if (*s & 0x80) {
+    len = 2;
+  } else {
+    len = 1;
+  }
+  return(len);
+}
+
+/*
+ * convert UTF-8 to pg_wchar (UCS-2)
+ * caller should allocate enough space for "to"
+ * len: length of from.
+ * "from" not necessarily null terminated.
+ */
+static void pg_utf2wchar_with_len(const unsigned char *from, pg_wchar *to, int len)
+{
+  unsigned char c1,c2,c3;
+  while (*from && len > 0) {
+    if ((*from & 0x80) == 0) {
+      *to = *from++;
+      len--;
+    } else if ((*from & 0xe0) == 0xc0) {
+      c1 = *from++ & 0x1f;
+      c2 = *from++ & 0x3f;
+      len -= 2;
+      *to = c1 << 6;
+      *to |= c2;
+    } else if ((*from & 0xe0) == 0xe0) {
+      c1 = *from++ & 0x0f;
+      c2 = *from++ & 0x3f;
+      c3 = *from++ & 0x3f;
+      len -= 3;
+      *to = c1 << 12;
+      *to |= c2 << 6;
+      *to |= c3;
+    }
+    to++;
+  }
+  *to = 0;
+}
+
+static int pg_utf_mblen(const unsigned char *s)
+{
+  int len = 1;
+
+  if ((*s & 0x80) == 0) {
+    len = 1;
+  } else if ((*s & 0xe0) == 0xc0) {
+    len = 2;
+  } else if ((*s & 0xe0) == 0xe0) {
+    len = 3;
+  }
+  return(len);
+}
+
+/*
+ * convert mule internal code to pg_wchar
+ * caller should allocate enough space for "to"
+ * len: length of from.
+ * "from" not necessarily null terminated.
+ */
+static void pg_mule2wchar_with_len(const unsigned char *from, pg_wchar *to, int len)
+{
+  while (*from && len > 0) {
+    if (IS_LC1(*from)) {
+      *to = *from++ << 16;
+      *to |= *from++;
+      len -= 2;
+    } else if (IS_LCPRV1(*from)) {
+      from++;
+      *to = *from++ << 16;
+      *to |= *from++;
+      len -= 3;
+    } else if (IS_LC2(*from)) {
+      *to = *from++ << 16;
+      *to |= *from++ << 8;
+      *to |= *from++;
+      len -= 3;
+    } else if (IS_LCPRV2(*from)) {
+      from++;
+      *to = *from++ << 16;
+      *to |= *from++ << 8;
+      *to |= *from++;
+      len -= 4;
+    } else {	/* assume ASCII */
+      *to = (unsigned char)*from++;
+      len--;
+    }
+    to++;
+  }
+  *to = 0;
+}
+
+int pg_mule_mblen(const unsigned char *s)
+{
+  int len;
+
+  if (IS_LC1(*s)) {
+    len = 2;
+  } else if (IS_LCPRV1(*s)) {
+    len = 3;
+  } else if (IS_LC2(*s)) {
+    len = 3;
+  } else if (IS_LCPRV2(*s)) {
+    len = 4;
+  } else {	/* assume ASCII */
+    len = 1;
+  }
+  return(len);
+}
+
+/*
+ * ISO8859-1
+ */
+static void pg_latin12wchar_with_len(const unsigned char *from, pg_wchar *to, int len)
+{
+  while (*from && len-- > 0) {
+    *to++ = *from++;
+  }
+  *to = 0;
+}
+
+static int pg_latin1_mblen(const unsigned char *s)
+{
+  return(1);
+}
+
+/*
+ * SJIS
+ */
+static int pg_sjis_mblen(const unsigned char *s)
+{
+  int len;
+
+  if (*s >= 0xa1 && *s <= 0xdf) {	/* 1 byte kana? */
+    len = 1;
+  } else if (*s > 0x7f) {	/* kanji? */
+    len = 2;
+  } else {	/* should be ASCII */
+    len = 1;
+  }
+  return(len);
+}
+
+pg_wchar_tbl pg_wchar_table[] = {
+  {pg_eucjp2wchar_with_len, pg_eucjp_mblen},
+  {pg_euccn2wchar_with_len, pg_euccn_mblen},
+  {pg_euckr2wchar_with_len, pg_euckr_mblen},
+  {pg_euctw2wchar_with_len, pg_euctw_mblen},
+  {pg_utf2wchar_with_len, pg_utf_mblen},
+  {pg_mule2wchar_with_len, pg_mule_mblen},
+  {pg_latin12wchar_with_len, pg_latin1_mblen},
+  {pg_latin12wchar_with_len, pg_latin1_mblen},
+  {pg_latin12wchar_with_len, pg_latin1_mblen},
+  {pg_latin12wchar_with_len, pg_latin1_mblen},
+  {pg_latin12wchar_with_len, pg_latin1_mblen},
+  {0, 0},
+  {0, 0},
+  {0, 0},
+  {0, 0},
+  {0, 0},
+  {0, 0},
+  {0, 0},
+  {0, 0},
+  {0, 0},
+  {0, 0},
+  {0, 0},
+  {0, 0},
+  {0, 0},
+  {0, 0},
+  {0, 0},
+  {0, 0},
+  {0, 0},
+  {0, 0},
+  {0, 0},
+  {0, 0},
+  {0, 0},
+  {0, pg_sjis_mblen}
+};
+
+/* returns the byte length of a word for mule internal code */
+int pg_mic_mblen(const unsigned char *mbstr)
+{
+  return(pg_mule_mblen(mbstr));
+}