Merge the last few variable.c configuration variables into the generic

GUC support.  It's now possible to set datestyle, timezone, and
client_encoding from postgresql.conf and per-database or per-user
settings.  Also, implement rollback of SET commands that occur in a
transaction that later fails.  Create a SET LOCAL var = value syntax
that sets the variable only for the duration of the current transaction.
All per previous discussions in pghackers.

src/backend/utils/adt/datetime.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/datetime.c,v 1.89 2002/04/21 19:48:12 thomas Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/datetime.c,v 1.90 2002/05/17 01:19:18 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -3571,11 +3571,17 @@ EncodeInterval(struct tm * tm, fsec_t fsec, int style, char *str)
 }	/* EncodeInterval() */
 
 
-void
-ClearDateCache(bool dummy)
+/* GUC assign_hook for australian_timezones */
+bool
+ClearDateCache(bool newval, bool doit, bool interactive)
 {
 	int			i;
 
-	for (i = 0; i < MAXDATEFIELDS; i++)
-		datecache[i] = NULL;
+	if (doit)
+	{
+		for (i = 0; i < MAXDATEFIELDS; i++)
+			datecache[i] = NULL;
+	}
+
+	return true;
 }

src/backend/utils/adt/pg_locale.c

@@ -2,7 +2,7 @@
  *
  * PostgreSQL locale utilities
  *
- * $Header: /cvsroot/pgsql/src/backend/utils/adt/pg_locale.c,v 1.16 2002/04/03 05:39:31 petere Exp $
+ * $Header: /cvsroot/pgsql/src/backend/utils/adt/pg_locale.c,v 1.17 2002/05/17 01:19:18 tgl Exp $
  *
  * Portions Copyright (c) 2002, PostgreSQL Global Development Group
  *
@@ -10,89 +10,73 @@
  */
 
 #include "postgres.h"
-#include "utils/pg_locale.h"
+
 #include <locale.h>
 
+#include "utils/pg_locale.h"
+
 
 /* GUC storage area */
 
-char * locale_messages;
-char * locale_monetary;
-char * locale_numeric;
-char * locale_time;
+char *locale_messages;
+char *locale_monetary;
+char *locale_numeric;
+char *locale_time;
 
-/* GUC parse hooks */
-
-bool locale_messages_check(const char *proposed)
-{
-#ifdef LC_MESSAGES
-	return chklocale(LC_MESSAGES, proposed);
-#else
-	/* We return true here so LC_MESSAGES can be set in the
-       configuration file on every system. */
-	return true;
-#endif
-}
-
-bool locale_monetary_check(const char *proposed)
-{
-	return chklocale(LC_MONETARY, proposed);
-}
-
-bool locale_numeric_check(const char *proposed)
-{
-	return chklocale(LC_NUMERIC, proposed);
-}
-
-bool locale_time_check(const char *proposed)
-{
-	return chklocale(LC_TIME, proposed);
-}
 
 /* GUC assign hooks */
 
-void locale_messages_assign(const char *value)
+static const char *
+locale_xxx_assign(int category, const char *value, bool doit, bool interactive)
 {
+	if (doit)
+	{
+		if (!setlocale(category, value))
+			return NULL;
+	}
+	else
+	{
+		char *save;
+
+		save = setlocale(category, NULL);
+		if (!save)
+			return NULL;
+
+		if (!setlocale(category, value))
+			return NULL;
+
+		setlocale(category, save);
+	}
+	return value;
+}
+
+const char *
+locale_messages_assign(const char *value, bool doit, bool interactive)
+{
+	/* LC_MESSAGES category does not exist everywhere, but accept it anyway */
 #ifdef LC_MESSAGES
-	setlocale(LC_MESSAGES, value);
+	return locale_xxx_assign(LC_MESSAGES, value, doit, interactive);
+#else
+	return value;
 #endif
 }
 
-void locale_monetary_assign(const char *value)
+const char *
+locale_monetary_assign(const char *value, bool doit, bool interactive)
 {
-	setlocale(LC_MONETARY, value);
+	return locale_xxx_assign(LC_MONETARY, value, doit, interactive);
 }
 
-void locale_numeric_assign(const char *value)
+const char *
+locale_numeric_assign(const char *value, bool doit, bool interactive)
 {
-	setlocale(LC_NUMERIC, value);
+	return locale_xxx_assign(LC_NUMERIC, value, doit, interactive);
 }
 
-void locale_time_assign(const char *value)
+const char *
+locale_time_assign(const char *value, bool doit, bool interactive)
 {
-	setlocale(LC_TIME, value);
-}
-
-
-/*
- * Returns true if the proposed string represents a valid locale of
- * the given category.  This is probably pretty slow, but it's not
- * called in critical places.
- */
-bool
-chklocale(int category, const char *proposed)
-{
-	char *save;
-
-	save = setlocale(category, NULL);
-	if (!save)
-		return false;
-
-	if (!setlocale(category, proposed))
-		return false;
-
-	setlocale(category, save);
-	return true;
+	return locale_xxx_assign(LC_TIME, value, doit, interactive);
 }
 
 
@@ -123,7 +107,6 @@ lc_collate_is_c(void)
 }
 
 
-
 /*
  * Return the POSIX lconv struct (contains number/money formatting
  * information) with locale information for all categories.
@@ -131,10 +114,11 @@ lc_collate_is_c(void)
 struct lconv *
 PGLC_localeconv(void)
 {
-	struct lconv *extlconv;
 	static bool CurrentLocaleConvValid = false;
 	static struct lconv CurrentLocaleConv;
 
+	struct lconv *extlconv;
+
 	/* Did we do it already? */
 	if (CurrentLocaleConvValid)
 		return &CurrentLocaleConv;

src/backend/utils/adt/ruleutils.c

@@ -3,7 +3,7 @@
  *				back to source text
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/ruleutils.c,v 1.104 2002/05/12 23:43:03 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/ruleutils.c,v 1.105 2002/05/17 01:19:18 tgl Exp $
  *
  *	  This software is copyrighted by Jan Wieck - Hamburg.
  *
@@ -2576,27 +2576,33 @@ quote_identifier(const char *ident)
 	 * and contains only lowercase letters, digits, and underscores, *and* is
 	 * not any SQL keyword.  Otherwise, supply quotes.
 	 */
+	int			nquotes = 0;
 	bool		safe;
+	const char *ptr;
 	char	   *result;
+	char	   *optr;
 
 	/*
 	 * would like to use <ctype.h> macros here, but they might yield
 	 * unwanted locale-specific results...
 	 */
 	safe = ((ident[0] >= 'a' && ident[0] <= 'z') || ident[0] == '_');
-	if (safe)
+
+	for (ptr = ident; *ptr; ptr++)
 	{
-		const char *ptr;
+		char		ch = *ptr;
 
-		for (ptr = ident + 1; *ptr; ptr++)
+		if ((ch >= 'a' && ch <= 'z') ||
+			(ch >= '0' && ch <= '9') ||
+			(ch == '_'))
 		{
-			char		ch = *ptr;
-
-			safe = ((ch >= 'a' && ch <= 'z') ||
-					(ch >= '0' && ch <= '9') ||
-					(ch == '_'));
-			if (!safe)
-				break;
+			/* okay */
+		}
+		else
+		{
+			safe = false;
+			if (ch == '"')
+				nquotes++;
 		}
 	}
 
@@ -2618,8 +2624,21 @@ quote_identifier(const char *ident)
 	if (safe)
 		return ident;			/* no change needed */
 
-	result = (char *) palloc(strlen(ident) + 2 + 1);
-	sprintf(result, "\"%s\"", ident);
+	result = (char *) palloc(strlen(ident) + nquotes + 2 + 1);
+
+	optr = result;
+	*optr++ = '"';
+	for (ptr = ident; *ptr; ptr++)
+	{
+		char		ch = *ptr;
+
+		if (ch == '"')
+			*optr++ = '"';
+		*optr++ = ch;
+	}
+	*optr++ = '"';
+	*optr = '\0';
+
 	return result;
 }