From 8a376ae237f108bdff96d15bfffd5231d1dd78df Mon Sep 17 00:00:00 2001
From: Vladislav Vaintroub <wlad@montyprogram.com>
Date: Sat, 14 May 2011 18:37:20 +0200
Subject: [PATCH] LPBUG#782223 : Memory released by Query_cache::resize() or
 Query_cache::free() contains active rwlocks. The bug was found by application
 verifier. Fixed by destroying locks prior to free(),

---
 sql/sql_cache.cc | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/sql/sql_cache.cc b/sql/sql_cache.cc
index 81cc87723c5..f358d5537d2 100644
--- a/sql/sql_cache.cc
+++ b/sql/sql_cache.cc
@@ -2253,6 +2253,18 @@ void Query_cache::free_cache()
 {
   DBUG_ENTER("Query_cache::free_cache");
 
+  /* Destroy locks */
+  Query_cache_block *block= queries_blocks;
+  if (block)
+  {
+    do
+    {
+      Query_cache_query *query= block->query();
+      my_rwlock_destroy(&query->lock);
+      block= block->next;
+    } while (block != queries_blocks);
+  }
+
   my_free((uchar*) cache, MYF(MY_ALLOW_ZERO_PTR));
   make_disabled();
   hash_free(&queries);