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:
  test case
mysql-test/t/query_cache.test:
  test case
sql/sql_cache.cc:
  Restore the memory block count to 0 for consistency.

1 files changed, 10 insertions, 0 deletions

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;