Replace argument-checking Asserts with regular test-and-elog checks in all

encoding conversion functions.  These are not can't-happen cases because
it's possible to create a conversion with the wrong conversion function
for the specified encoding pair.  That would lead to an Assert crash in
an Assert-enabled build, or incorrect conversion otherwise, neither of
which is desirable.  This would be a DOS issue if production databases
were customarily built with asserts enabled, but fortunately that's not so.
Per an observation by Heikki.

Back-patch to all supported branches.

1 files changed, 20 insertions, 1 deletions

diff --git a/src/include/mb/pg_wchar.h b/src/include/mb/pg_wchar.h
index 2d465a1b38b..88304b5f69c 100644
--- a/src/include/mb/pg_wchar.h
+++ b/src/include/mb/pg_wchar.h
@@ -1,4 +1,4 @@
-/* $PostgreSQL: pgsql/src/include/mb/pg_wchar.h,v 1.69 2006/10/04 00:30:09 momjian Exp $ */
+/* $PostgreSQL: pgsql/src/include/mb/pg_wchar.h,v 1.69.2.1 2009/01/29 19:24:19 tgl Exp $ */
 
 #ifndef PG_WCHAR_H
 #define PG_WCHAR_H
@@ -291,6 +291,19 @@ typedef struct
 	unsigned int utf;			/* UTF8 */
 } pg_local_to_utf;
 
+/*
+ * Support macro for encoding conversion functions to validate their
+ * arguments.  (This could be made more compact if we included fmgr.h
+ * here, but we don't want to do that because this header file is also
+ * used by frontends.)
+ */
+#define CHECK_ENCODING_CONVERSION_ARGS(srcencoding,destencoding) \
+	check_encoding_conversion_args(PG_GETARG_INT32(0), \
+								   PG_GETARG_INT32(1), \
+								   PG_GETARG_INT32(4), \
+								   (srcencoding), \
+								   (destencoding))
+
 extern int	pg_mb2wchar(const char *from, pg_wchar *to);
 extern int	pg_mb2wchar_with_len(const char *from, pg_wchar *to, int len);
 extern int	pg_char_and_wchar_strcmp(const char *s1, const pg_wchar *s2);
@@ -345,6 +358,12 @@ extern bool pg_verifymbstr(const char *mbstr, int len, bool noError);
 extern bool pg_verify_mbstr(int encoding, const char *mbstr, int len,
 				bool noError);
 
+extern void check_encoding_conversion_args(int src_encoding,
+										   int dest_encoding,
+										   int len,
+										   int expected_src_encoding,
+										   int expected_dest_encoding);
+
 extern void report_invalid_encoding(int encoding, const char *mbstr, int len);
 extern void report_untranslatable_char(int src_encoding, int dest_encoding,
 						   const char *mbstr, int len);