Fix usage of char2wchar/wchar2char. Changes:

- pg_wchar and wchar_t could have different size, so char2wchar
  doesn't call pg_mb2wchar_with_len to prevent out-of-bound
  memory bug
- make char2wchar/wchar2char symmetric, now they should not be
  called with C-locale because mbstowcs/wcstombs oftenly doesn't
  work correct with C-locale.
- Text parser uses pg_mb2wchar_with_len directly in case of
  C-locale and multibyte encoding

Per bug report by Hiroshi Inoue <inoue@tpf.co.jp> and
following discussion.

Backpatch up to 8.2 when multybyte support was implemented in tsearch.

1 files changed, 9 insertions, 16 deletions

diff --git a/src/backend/utils/mb/mbutils.c b/src/backend/utils/mb/mbutils.c
index c3cf7f5db6..f5ba80d101 100644
--- a/src/backend/utils/mb/mbutils.c
+++ b/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 1.78 2009/01/22 10:09:48 mha Exp $
+ * $PostgreSQL: pgsql/src/backend/utils/mb/mbutils.c,v 1.79 2009/03/02 15:10:09 teodor Exp $
  */
 #include "postgres.h"
 
@@ -601,7 +601,10 @@ wchar2char(char *to, const wchar_t *from, size_t tolen)
 	}
 	else
 #endif   /* WIN32 */
+	{
+		Assert( !lc_ctype_is_c() );
 		result = wcstombs(to, from, tolen);
+	}
 	return result;
 }
 
@@ -647,22 +650,12 @@ char2wchar(wchar_t *to, size_t tolen, const char *from, size_t fromlen)
 	else
 #endif   /* WIN32 */
 	{
-		if (lc_ctype_is_c())
-		{
-			/*
-			 * pg_mb2wchar_with_len always adds trailing '\0', so 'to' should be
-			 * allocated with sufficient space
-			 */
-			result = pg_mb2wchar_with_len(from, (pg_wchar *) to, fromlen);
-		}
-		else
-		{
-			/* mbstowcs requires ending '\0' */
-			char	   *str = pnstrdup(from, fromlen);
+		/* mbstowcs requires ending '\0' */
+		char	   *str = pnstrdup(from, fromlen);
 
-			result = mbstowcs(to, str, tolen);
-			pfree(str);
-		}
+		Assert( !lc_ctype_is_c() );
+		result = mbstowcs(to, str, tolen);
+		pfree(str);
 	}
 
 	if (result == -1)