From e7db8fa80e58d43531469547e0f0ac1da77d3a8c Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Mon, 4 Mar 2002 18:34:02 +0000
Subject: [PATCH] Add Assert check to catch vsnprintf overrunning its buffer.
(Seen to occur on Solaris 7 in 64-bit mode, for one.)
---
src/backend/lib/stringinfo.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/src/backend/lib/stringinfo.c b/src/backend/lib/stringinfo.c
index 1745f0f9ca1..544ae1b3a20 100644
--- a/src/backend/lib/stringinfo.c
+++ b/src/backend/lib/stringinfo.c
@@ -9,7 +9,7 @@
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $Id: stringinfo.c,v 1.29 2001/10/25 05:49:29 momjian Exp $
+ * $Id: stringinfo.c,v 1.30 2002/03/04 18:34:02 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -114,11 +114,22 @@ appendStringInfo(StringInfo str, const char *fmt,...)
avail = str->maxlen - str->len - 1;
if (avail > 16)
{
+ /*
+ * Assert check here is to catch buggy vsnprintf that overruns
+ * the specified buffer length. Solaris 7 in 64-bit mode is
+ * an example of a platform with such a bug.
+ */
+#ifdef USE_ASSERT_CHECKING
+ str->data[str->maxlen-1] = '\0';
+#endif
+
va_start(args, fmt);
nprinted = vsnprintf(str->data + str->len, avail,
fmt, args);
va_end(args);
+ Assert(str->data[str->maxlen-1] == '\0');
+
/*
* Note: some versions of vsnprintf return the number of chars
* actually stored, but at least one returns -1 on failure. Be
--
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