Merge adventure.(none):/home/thek/Development/cpp/bug30887/my51-bug30887

into  adventure.(none):/home/thek/Development/cpp/mysql-5.1-runtime


sql/sql_cache.cc:
  Auto merged

2 files changed, 65 insertions, 0 deletions

diff --git a/mysql-test/r/query_cache.result b/mysql-test/r/query_cache.result
index 1a728354c7b..f813d2cc7e0 100644
--- a/mysql-test/r/query_cache.result
+++ b/mysql-test/r/query_cache.result
@@ -1669,4 +1669,28 @@ SELECT 1 FROM t1 GROUP BY
 1
 1
 DROP TABLE t1;
+flush status;
+set query_cache_type=DEMAND;
+set global query_cache_size= 1024*1024*512;
+drop table if exists t1;
+create table t1 (a varchar(100));
+insert into t1 values ('aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa'),('bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb');
+Activate debug hook and attempt to retrieve the statement from the cache.
+set session debug='+d,wait_in_query_cache_insert';
+select SQL_CACHE * from t1;;
+On a second connection; clear the query cache.
+show status like 'Qcache_queries_in_cache';
+Variable_name	Value
+Qcache_queries_in_cache	1
+set global query_cache_size= 0;;
+Signal the debug hook to release the lock.
+select id from information_schema.processlist where state='wait_in_query_cache_insert' into @thread_id;
+kill query @thread_id;
+Show query cache status.
+show status like 'Qcache_queries_in_cache';
+Variable_name	Value
+Qcache_queries_in_cache	1
+set global query_cache_size= 0;
+use test;
+drop table t1;
 End of 5.1 tests
diff --git a/mysql-test/t/query_cache.test b/mysql-test/t/query_cache.test
index 9e250372d51..14cd9385ca6 100644
--- a/mysql-test/t/query_cache.test
+++ b/mysql-test/t/query_cache.test
@@ -1316,6 +1316,47 @@ SELECT 1 FROM t1 GROUP BY
   (SELECT LAST_INSERT_ID() FROM t1 ORDER BY MIN(a) ASC LIMIT 1);
 DROP TABLE t1;
 
+#
+# Bug #30887 Server crashes on SET GLOBAL query_cache_size=0
+#
+flush status;
+set query_cache_type=DEMAND;
+set global query_cache_size= 1024*1024*512;
+--disable_warnings
+drop table if exists t1;
+--enable_warnings
+create table t1 (a varchar(100));
+insert into t1 values ('aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa'),('bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb');
+connect (bug30887con1, localhost, root, ,test);
+connect (bug30887con2, localhost, root, ,test);
+
+connection bug30887con1;
+--echo Activate debug hook and attempt to retrieve the statement from the cache.
+set session debug='+d,wait_in_query_cache_insert';
+--send select SQL_CACHE * from t1;
+
+connection default;
+let $wait_condition= select count(*)= 1 from information_schema.processlist where state= 'wait_in_query_cache_insert';
+--source include/wait_condition.inc
+
+connection bug30887con2;
+--echo On a second connection; clear the query cache.
+show status like 'Qcache_queries_in_cache';
+--send set global query_cache_size= 0;
+
+connection default;
+--echo Signal the debug hook to release the lock.
+select id from information_schema.processlist where state='wait_in_query_cache_insert' into @thread_id;
+kill query @thread_id;
+
+--echo Show query cache status.
+show status like 'Qcache_queries_in_cache';
+
+disconnect bug30887con1;
+disconnect bug30887con2;
+set global query_cache_size= 0;
+use test;
+drop table t1;
 
 --echo End of 5.1 tests