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 dc89af9d507..65c99a2797f 100644
--- a/src/include/mb/pg_wchar.h
+++ b/src/include/mb/pg_wchar.h
@@ -6,7 +6,7 @@
  * Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/mb/pg_wchar.h,v 1.82 2009/01/04 18:37:36 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/mb/pg_wchar.h,v 1.83 2009/01/29 19:23:42 tgl Exp $
  *
  *	NOTES
  *		This is used both by the backend and by libpq, but should not be
@@ -325,6 +325,19 @@ typedef struct
 	uint32		utf2;			/* UTF-8 code 2 */
 } pg_local_to_utf_combined;
 
+/*
+ * 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))
+
 
 /*
  * These functions are considered part of libpq's exported API and
@@ -408,6 +421,12 @@ extern bool pg_verify_mbstr(int encoding, const char *mbstr, int len,
 extern int pg_verify_mbstr_len(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);