From a13cba5abd351c3916af0fc6404109e787fd8085 Mon Sep 17 00:00:00 2001
From: "thek@adventure.(none)" <>
Date: Thu, 6 Mar 2008 12:40:46 +0100
Subject: [PATCH] Bug#25132 disabled query cache: Qcache_free_blocks = 1

The initial value of free memory blocks in 0. When the query cache is enabled
a new memory block gets allocated and is assigned number 1. The free memory
block is later split each time query cache memory is allocated for new blocks.
This means that the free memory block counter won't be reduced to zero when
the number of allocated blocks are zero, but rather one. To avoid confusion
this patch changes this behavior so that the free memory block counter is
reset to zero when the query cache is disabled.
Note that when the query cache is enabled and resized the free memory block
counter was still calculated correctly.
---
 mysql-test/r/query_cache.result | 10 ++++++++++
 mysql-test/t/query_cache.test   |  9 +++++++++
 sql/sql_cache.cc                |  1 +
 3 files changed, 20 insertions(+)

diff --git a/mysql-test/r/query_cache.result b/mysql-test/r/query_cache.result
index 68f18d1b0b2..b47c91b0406 100644
--- a/mysql-test/r/query_cache.result
+++ b/mysql-test/r/query_cache.result
@@ -1650,6 +1650,16 @@ Variable_name	Value
 Qcache_queries_in_cache	1
 DROP DATABASE bug30269;
 DROP USER 'bug30269'@'localhost';
+#
+# Bug#25132 disabled query cache: Qcache_free_blocks = 1
+#
+set global query_cache_size=100000;
+set global query_cache_size=0;
+set global query_cache_type=0;
+show status like 'Qcache_free_blocks';
+Variable_name	Value
+Qcache_free_blocks	0
+Restore default values.
 set GLOBAL query_cache_type=default;
 set GLOBAL query_cache_limit=default;
 set GLOBAL query_cache_min_res_unit=default;
diff --git a/mysql-test/t/query_cache.test b/mysql-test/t/query_cache.test
index 44b63df9739..e0042ab6311 100644
--- a/mysql-test/t/query_cache.test
+++ b/mysql-test/t/query_cache.test
@@ -1251,6 +1251,15 @@ DROP DATABASE bug30269;
 disconnect bug30269;
 DROP USER 'bug30269'@'localhost';
 
+--echo #
+--echo # Bug#25132 disabled query cache: Qcache_free_blocks = 1
+--echo #
+set global query_cache_size=100000;
+set global query_cache_size=0;
+set global query_cache_type=0;
+show status like 'Qcache_free_blocks';
+
+--echo Restore default values.
 set GLOBAL query_cache_type=default;
 set GLOBAL query_cache_limit=default;
 set GLOBAL query_cache_min_res_unit=default;
diff --git a/sql/sql_cache.cc b/sql/sql_cache.cc
index 8c868971911..2bf00e7e51f 100644
--- a/sql/sql_cache.cc
+++ b/sql/sql_cache.cc
@@ -1794,6 +1794,7 @@ void Query_cache::make_disabled()
   query_cache_size= 0;
   queries_blocks= 0;
   free_memory= 0;
+  free_memory_blocks= 0;
   bins= 0;
   steps= 0;
   cache= 0;