From d903915f938c33592b20bdba5f27a4aba01c3c8d Mon Sep 17 00:00:00 2001
From: Andrey Hristov <andrey@php.net>
Date: Thu, 17 Mar 2011 10:28:53 +0000
Subject: [PATCH] Fix for bug #54221 mysqli::get_warnings segfault when used in
 multi queries

---
 ext/mysqli/mysqli_warning.c    |  2 +-
 ext/mysqli/tests/bug54221.phpt | 47 ++++++++++++++++++++++++++++++++++
 2 files changed, 48 insertions(+), 1 deletion(-)
 create mode 100644 ext/mysqli/tests/bug54221.phpt

diff --git a/ext/mysqli/mysqli_warning.c b/ext/mysqli/mysqli_warning.c
index 09fa5b3510..ee815121b3 100644
--- a/ext/mysqli/mysqli_warning.c
+++ b/ext/mysqli/mysqli_warning.c
@@ -197,7 +197,7 @@ PHP_METHOD(mysqli_warning, next)
 
 		MYSQLI_FETCH_RESOURCE(w, MYSQLI_WARNING *, &mysqli_warning, "mysqli_warning", MYSQLI_STATUS_VALID);
 
-		if (w->next) {
+		if (w && w->next) {
 			w = w->next;
 	        ((MYSQLI_RESOURCE *)(obj->ptr))->ptr = w;
 			RETURN_TRUE;
diff --git a/ext/mysqli/tests/bug54221.phpt b/ext/mysqli/tests/bug54221.phpt
new file mode 100644
index 0000000000..78c9a2c40e
--- /dev/null
+++ b/ext/mysqli/tests/bug54221.phpt
@@ -0,0 +1,47 @@
+--TEST--
+Bug #54221 mysqli::get_warnings segfault when used in multi queries
+--SKIPIF--
+<?php
+require_once('skipif.inc');
+require_once('skipifconnectfailure.inc');
+?>
+--INI--
+mysqli.max_links = 1
+mysqli.allow_persistent = Off
+mysqli.max_persistent = 0
+mysqli.reconnect = Off
+--FILE--
+<?php
+	include ("connect.inc");
+
+	$link = mysqli_init();
+	if (!my_mysqli_real_connect($link, $host, $user, $passwd, $db, $port, $socket)) {
+		printf("[002] Connect failed, [%d] %s\n", mysqli_connect_errno(), mysqli_connect_error());
+	}
+
+	$create = "CREATE TEMPORARY TABLE IF NOT EXISTS t54221(a int)";
+
+	$query = "$create;$create;$create;";
+	if ($link->multi_query($query)) {
+		do {
+			$sth = $link->store_result();
+
+			if ($link->warning_count) {
+				$warnings = $link->get_warnings();
+				if ($warnings) {
+					do {
+						echo "Warning: ".$warnings->errno.": ".$warnings->message."\n"; 
+					} while ($warnings->next());
+				}
+			}
+		} while ($link->more_results() && $link->next_result());
+	}
+
+	mysqli_close($link);
+
+	print "done!";
+?>
+--EXPECTF--
+Warning: : 
+Warning: 1050: Table 't54221' already exists
+done!
-- 
2.50.1