From c4e0c113b8f7069be6a866a25f121611908fd07c Mon Sep 17 00:00:00 2001
From: Tatsuo Ishii <ishii@postgresql.org>
Date: Mon, 15 Apr 2002 07:54:37 +0000
Subject: [PATCH] Fix text_substr bug intrduced in 7.3 development using Joe
Conway's patches (submitted at pgsql-patches on 2002/04/08) + small fix.
---
src/backend/utils/adt/varlena.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/src/backend/utils/adt/varlena.c b/src/backend/utils/adt/varlena.c
index 0cd38a76bee..2007e78910f 100644
--- a/src/backend/utils/adt/varlena.c
+++ b/src/backend/utils/adt/varlena.c
@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/utils/adt/varlena.c,v 1.82 2002/04/03 05:39:32 petere Exp $
+ * $Header: /cvsroot/pgsql/src/backend/utils/adt/varlena.c,v 1.83 2002/04/15 07:54:37 ishii Exp $
*
*-------------------------------------------------------------------------
*/
@@ -373,7 +373,10 @@ text_substr(PG_FUNCTION_ARGS)
if (eml > 1)
{
sm = 0;
- sn = (m + n) * eml + 3; /* +3 to avoid mb characters overhanging slice end */
+ if (n > -1)
+ sn = (m + n) * eml + 3; /* +3 to avoid mb characters overhanging slice end */
+ else
+ sn = n; /* n < 0 is special-cased by heap_tuple_untoast_attr_slice */
}
#endif
@@ -387,7 +390,10 @@ text_substr(PG_FUNCTION_ARGS)
PG_RETURN_NULL(); /* notreached: suppress compiler warning */
#endif
#ifdef MULTIBYTE
- len = pg_mbstrlen_with_len (VARDATA (string), sn - 3);
+ if (n > -1)
+ len = pg_mbstrlen_with_len (VARDATA (string), sn - 3);
+ else /* n < 0 is special-cased; need full string length */
+ len = pg_mbstrlen_with_len (VARDATA (string), VARSIZE(string)-VARHDRSZ);
if (m > len)
{
--
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