Fix the inadvertent libpq ABI breakage discovered by Martin Pitt: the

renumbering of encoding IDs done between 8.2 and 8.3 turns out to break 8.2
initdb and psql if they are run with an 8.3beta1 libpq.so.  For the moment
we can rearrange the order of enum pg_enc to keep the same number for
everything except PG_JOHAB, which isn't a problem since there are no direct
references to it in the 8.2 programs anyway.  (This does force initdb
unfortunately.)

Going forward, we want to fix things so that encoding IDs can be changed
without an ABI break, and this commit includes the changes needed to allow
libpq's encoding IDs to be treated as fully independent of the backend's.
The main issue is that libpq clients should not include pg_wchar.h or
otherwise assume they know the specific values of libpq's encoding IDs,
since they might encounter version skew between pg_wchar.h and the libpq.so
they are using.  To fix, have libpq officially export functions needed for
encoding name<=>ID conversion and validity checking; it was doing this
anyway unofficially.

It's still the case that we can't renumber backend encoding IDs until the
next bump in libpq's major version number, since doing so will break the
8.2-era client programs.  However the code is now prepared to avoid this
type of problem in future.

Note that initdb is no longer a libpq client: we just pull in the two
source files we need directly.  The patch also fixes a few places that
were being sloppy about checking for an unrecognized encoding name.

Author: tglsfdc

src/backend/commands/dbcommands.c

@@ -13,7 +13,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/dbcommands.c,v 1.200 2007/10/12 18:55:12 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/dbcommands.c,v 1.201 2007/10/13 20:18:41 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -178,12 +178,12 @@ createdb(const CreatedbStmt *stmt)
 		else if (IsA(dencoding->arg, String))
 		{
 			encoding_name = strVal(dencoding->arg);
-			if (pg_valid_server_encoding(encoding_name) < 0)
+			encoding = pg_valid_server_encoding(encoding_name);
+			if (encoding < 0)
 				ereport(ERROR,
 						(errcode(ERRCODE_UNDEFINED_OBJECT),
 						 errmsg("%s is not a valid encoding name",
 								encoding_name)));
-			encoding = pg_char_to_encoding(encoding_name);
 		}
 		else
 			elog(ERROR, "unrecognized node type: %d",

src/backend/utils/adt/ascii.c

@@ -5,7 +5,7 @@
  *	 Portions Copyright (c) 1999-2007, PostgreSQL Global Development Group
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/adt/ascii.c,v 1.30 2007/01/05 22:19:40 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/adt/ascii.c,v 1.31 2007/10/13 20:18:41 tgl Exp $
  *
  *-----------------------------------------------------------------------
  */
@@ -117,7 +117,13 @@ Datum
 to_ascii_encname(PG_FUNCTION_ARGS)
 {
 	text	   *data = PG_GETARG_TEXT_P_COPY(0);
-	int			enc = pg_char_to_encoding(NameStr(*PG_GETARG_NAME(1)));
+	char	   *encname = NameStr(*PG_GETARG_NAME(1));
+	int			enc = pg_char_to_encoding(encname);
+
+	if (enc < 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_OBJECT),
+				 errmsg("%s is not a valid encoding name", encname)));
 
 	PG_RETURN_TEXT_P(encode_to_ascii(data, enc));
 }
@@ -132,6 +138,11 @@ to_ascii_enc(PG_FUNCTION_ARGS)
 	text	   *data = PG_GETARG_TEXT_P_COPY(0);
 	int			enc = PG_GETARG_INT32(1);
 
+	if (!PG_VALID_ENCODING(enc))
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_OBJECT),
+				 errmsg("%d is not a valid encoding code", enc)));
+
 	PG_RETURN_TEXT_P(encode_to_ascii(data, enc));
 }
 

src/backend/utils/adt/xml.c

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/backend/utils/adt/xml.c,v 1.47 2007/09/23 21:36:42 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/utils/adt/xml.c,v 1.48 2007/10/13 20:18:41 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -127,6 +127,24 @@ XmlOptionType xmloption;
 #define NAMESPACE_SQLXML "http://standards.iso.org/iso/9075/2003/sqlxml"
 
 
+#ifdef USE_LIBXML
+
+static int
+xmlChar_to_encoding(xmlChar *encoding_name)
+{
+	int		encoding = pg_char_to_encoding((char *) encoding_name);
+
+	if (encoding < 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("invalid encoding name \"%s\"",
+						(char *) encoding_name)));
+	return encoding;
+}
+
+#endif
+
+
 Datum
 xml_in(PG_FUNCTION_ARGS)
 {
@@ -263,7 +281,9 @@ xml_recv(PG_FUNCTION_ARGS)
 	/* Now that we know what we're dealing with, convert to server encoding */
 	newstr = (char *) pg_do_encoding_conversion((unsigned char *) str,
 												nbytes,
-												encoding ? pg_char_to_encoding((char *) encoding) : PG_UTF8,
+												encoding ?
+												xmlChar_to_encoding(encoding) :
+												PG_UTF8,
 												GetDatabaseEncoding());
 
 	if (newstr != str)
@@ -1084,9 +1104,9 @@ xml_parse(text *data, XmlOptionType xmloption_arg, bool preserve_whitespace, xml
 
 	utf8string = pg_do_encoding_conversion(string,
 										   len,
-										   encoding
-										   ? pg_char_to_encoding((char *) encoding)
-										   : GetDatabaseEncoding(),
+										   encoding ?
+										   xmlChar_to_encoding(encoding) :
+										   GetDatabaseEncoding(),
 										   PG_UTF8);
 
 	xml_init();

src/backend/utils/mb/encnames.c

@@ -2,7 +2,7 @@
  * Encoding names and routines for work with it. All
  * in this file is shared bedween FE and BE.
  *
- * $PostgreSQL: pgsql/src/backend/utils/mb/encnames.c,v 1.34 2007/04/16 18:50:49 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/utils/mb/encnames.c,v 1.35 2007/10/13 20:18:41 tgl Exp $
  */
 #ifdef FRONTEND
 #include "postgres_fe.h"
@@ -12,10 +12,11 @@
 #include "utils/builtins.h"
 #endif
 
+#include <ctype.h>
 #include <unistd.h>
 
 #include "mb/pg_wchar.h"
-#include <ctype.h>
+
 
 /* ----------
  * All encoding names, sorted:		 *** A L P H A B E T I C ***
@@ -313,6 +314,9 @@ pg_enc2name pg_enc2name_tbl[] =
 	{
 		"EUC_TW", PG_EUC_TW
 	},
+	{
+		"EUC_JIS_2004", PG_EUC_JIS_2004
+	},
 	{
 		"UTF8", PG_UTF8
 	},
@@ -397,9 +401,6 @@ pg_enc2name pg_enc2name_tbl[] =
 	{
 		"WIN1257", PG_WIN1257
 	},
-	{
-		"EUC_JIS_2004", PG_EUC_JIS_2004
-	},
 	{
 		"SJIS", PG_SJIS
 	},
@@ -413,10 +414,10 @@ pg_enc2name pg_enc2name_tbl[] =
 		"UHC", PG_UHC
 	},
 	{
-		"JOHAB", PG_JOHAB
+		"GB18030", PG_GB18030
 	},
 	{
-		"GB18030", PG_GB18030
+		"JOHAB", PG_JOHAB
 	},
 	{
 		"SHIFT_JIS_2004", PG_SHIFT_JIS_2004
@@ -455,6 +456,12 @@ pg_valid_server_encoding(const char *name)
 	return enc;
 }
 
+int
+pg_valid_server_encoding_id(int encoding)
+{
+	return PG_VALID_BE_ENCODING(encoding);
+}
+
 /* ----------
  * Remove irrelevant chars from encoding name
  * ----------
@@ -533,14 +540,14 @@ pg_char_to_encname_struct(const char *name)
  * Returns encoding or -1 for error
  */
 int
-pg_char_to_encoding(const char *s)
+pg_char_to_encoding(const char *name)
 {
-	pg_encname *p = NULL;
+	pg_encname *p;
 
-	if (!s)
+	if (!name)
 		return -1;
 
-	p = pg_char_to_encname_struct(s);
+	p = pg_char_to_encname_struct(name);
 	return p ? p->encoding : -1;
 }
 

src/backend/utils/mb/mbutils.c

@@ -4,7 +4,7 @@
  * (currently mule internal code (mic) is used)
  * Tatsuo Ishii
  *
- * $PostgreSQL: pgsql/src/backend/utils/mb/mbutils.c,v 1.66 2007/09/24 16:38:24 adunstan Exp $
+ * $PostgreSQL: pgsql/src/backend/utils/mb/mbutils.c,v 1.67 2007/10/13 20:18:41 tgl Exp $
  */
 #include "postgres.h"
 
@@ -421,6 +421,12 @@ length_in_encoding(PG_FUNCTION_ARGS)
 	int         len = VARSIZE(string) - VARHDRSZ;
 	int         retval;
 
+	if (src_encoding < 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("invalid encoding name \"%s\"",
+						src_encoding_name)));
+
 	retval = pg_verify_mbstr_len(src_encoding, VARDATA(string), len, false);
 	PG_RETURN_INT32(retval);
 

src/bin/initdb/Makefile

@@ -5,7 +5,7 @@
 # Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
 # Portions Copyright (c) 1994, Regents of the University of California
 #
-# $PostgreSQL: pgsql/src/bin/initdb/Makefile,v 1.53 2007/09/27 19:53:43 tgl Exp $
+# $PostgreSQL: pgsql/src/bin/initdb/Makefile,v 1.54 2007/10/13 20:18:41 tgl Exp $
 #
 #-------------------------------------------------------------------------
 
@@ -14,14 +14,24 @@ subdir = src/bin/initdb
 top_builddir = ../../..
 include $(top_builddir)/src/Makefile.global
 
-override CPPFLAGS := -I$(libpq_srcdir) $(CPPFLAGS)
+override CPPFLAGS := -DFRONTEND -I$(libpq_srcdir) $(CPPFLAGS)
 
-OBJS=	initdb.o $(WIN32RES)
+OBJS=	initdb.o encnames.o pqsignal.o $(WIN32RES)
 
-all: submake-libpq submake-libpgport initdb
+all: submake-libpgport initdb
 
-initdb: $(OBJS) $(libpq_builddir)/libpq.a
-	$(CC) $(CFLAGS) $(OBJS) $(libpq_pgport) $(LDFLAGS) $(LIBS) -o $@$(X)
+initdb: $(OBJS)
+	$(CC) $(CFLAGS) $(OBJS) $(LDFLAGS) $(LIBS) -o $@$(X)
+
+# We used to pull in all of libpq to get encnames and pqsignal, but that
+# exposes us to risks of version skew if we link to a shared library.
+# Do it the hard way, instead, so that we're statically linked.
+
+encnames.c: % : $(top_srcdir)/src/backend/utils/mb/%
+	rm -f $@ && $(LN_S) $< .
+
+pqsignal.c: % : $(libpq_srcdir)/%
+	rm -f $@ && $(LN_S) $< .
 
 install: all installdirs
 	$(INSTALL_PROGRAM) initdb$(X) '$(DESTDIR)$(bindir)/initdb$(X)'
@@ -33,7 +43,7 @@ uninstall:
 	rm -f '$(DESTDIR)$(bindir)/initdb$(X)'
 
 clean distclean maintainer-clean:
-	rm -f initdb$(X) $(OBJS)
+	rm -f initdb$(X) $(OBJS) encnames.c pqsignal.c
 
 
 # ensure that changes in datadir propagate into object file

src/bin/initdb/initdb.c

@@ -42,7 +42,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  * Portions taken from FreeBSD.
  *
- * $PostgreSQL: pgsql/src/bin/initdb/initdb.c,v 1.144 2007/09/29 00:14:40 tgl Exp $
+ * $PostgreSQL: pgsql/src/bin/initdb/initdb.c,v 1.145 2007/10/13 20:18:41 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -2808,7 +2808,7 @@ main(int argc, char *argv[])
 					progname);
 			exit(1);
 		}
-		else if (!PG_VALID_BE_ENCODING(ctype_enc))
+		else if (!pg_valid_server_encoding_id(ctype_enc))
 		{
 			/* We recognized it, but it's not a legal server encoding */
 			fprintf(stderr,
@@ -2968,7 +2968,7 @@ main(int argc, char *argv[])
 	{
 		char	*linkloc;
 
-		linkloc = (char *) palloc(strlen(pg_data) + 8 + 2);
+		linkloc = (char *) pg_malloc(strlen(pg_data) + 8 + 2);
 		sprintf(linkloc, "%s/pg_xlog", pg_data);
 
 		/* check if the specified xlog directory is empty */

src/bin/pg_dump/pg_backup_archiver.c

@@ -15,7 +15,7 @@
  *
  *
  * IDENTIFICATION
- *		$PostgreSQL: pgsql/src/bin/pg_dump/pg_backup_archiver.c,v 1.146 2007/08/21 01:11:20 tgl Exp $
+ *		$PostgreSQL: pgsql/src/bin/pg_dump/pg_backup_archiver.c,v 1.147 2007/10/13 20:18:41 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -32,7 +32,6 @@
 #endif
 
 #include "libpq/libpq-fs.h"
-#include "mb/pg_wchar.h"
 
 
 const char *progname;
@@ -1639,7 +1638,7 @@ _allocAH(const char *FileSpec, const ArchiveFormat fmt,
 	AH->vrev = K_VERS_REV;
 
 	/* initialize for backwards compatible string processing */
-	AH->public.encoding = PG_SQL_ASCII;
+	AH->public.encoding = 0;	/* PG_SQL_ASCII */
 	AH->public.std_strings = false;
 
 	/* sql error handling */

src/bin/pg_dump/pg_dump.c

@@ -12,7 +12,7 @@
  *	by PostgreSQL
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/bin/pg_dump/pg_dump.c,v 1.472 2007/09/03 00:39:19 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/bin/pg_dump/pg_dump.c,v 1.473 2007/10/13 20:18:41 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -47,7 +47,6 @@ int			optreset;
 #include "catalog/pg_type.h"
 #include "commands/sequence.h"
 #include "libpq/libpq-fs.h"
-#include "mb/pg_wchar.h"
 
 #include "pg_backup_archiver.h"
 #include "dumputils.h"

src/bin/pg_dump/pg_dumpall.c

@@ -6,7 +6,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  *
- * $PostgreSQL: pgsql/src/bin/pg_dump/pg_dumpall.c,v 1.92 2007/07/08 19:07:38 tgl Exp $
+ * $PostgreSQL: pgsql/src/bin/pg_dump/pg_dumpall.c,v 1.93 2007/10/13 20:18:41 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -27,7 +27,6 @@ int			optreset;
 #endif
 
 #include "dumputils.h"
-#include "mb/pg_wchar.h"
 
 
 /* version string we expect back from pg_dump */

src/bin/psql/command.c

@@ -3,7 +3,7 @@
  *
  * Copyright (c) 2000-2007, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/bin/psql/command.c,v 1.181 2007/08/21 01:11:22 tgl Exp $
+ * $PostgreSQL: pgsql/src/bin/psql/command.c,v 1.182 2007/10/13 20:18:41 tgl Exp $
  */
 #include "postgres_fe.h"
 #include "command.h"
@@ -45,7 +45,6 @@
 #include "psqlscan.h"
 #include "settings.h"
 #include "variables.h"
-#include "mb/pg_wchar.h"
 
 
 /* functions for use in this file */
@@ -295,7 +294,7 @@ exec_command(const char *cmd,
 		}
 
 		if (pset.dirname)
-			pfree(pset.dirname);
+			free(pset.dirname);
 		pset.dirname = pg_strdup(dir);
 		canonicalize_path(pset.dirname);