1 files changed, 68 insertions, 0 deletions
diff --git a/mysql-test/t/query_cache_debug.test b/mysql-test/t/query_cache_debug.test
index 6834301adce..217dadf0ae8 100644
--- a/mysql-test/t/query_cache_debug.test
+++ b/mysql-test/t/query_cache_debug.test
@@ -45,3 +45,71 @@ set global query_cache_size= 0;
 use test;
 drop table t1;
 
+#
+# Bug#41098: Query Cache returns wrong result with concurrent insert
+#
+
+SET @old_concurrent_insert= @@GLOBAL.concurrent_insert;
+SET @old_query_cache_size= @@GLOBAL.query_cache_size;
+
+--disable_warnings
+DROP TABLE IF EXISTS t1, t2;
+--enable_warnings
+CREATE TABLE t1 (a INT);
+CREATE TABLE t2 (a INT);
+INSERT INTO t1 VALUES (1),(2),(3);
+
+SET GLOBAL concurrent_insert= 1;
+SET GLOBAL query_cache_size= 1024*512;
+SET GLOBAL query_cache_type= ON;
+
+connect(con1,localhost,root,,test,,);
+connect(con2,localhost,root,,test,,);
+
+connection con1;
+--echo # Switch to connection con1
+SET SESSION debug='+d,wait_after_query_cache_invalidate';
+--echo # Send concurrent insert, will wait in the query cache table invalidate
+--send INSERT INTO t1 VALUES (4)
+
+connection default;
+--echo # Switch to connection default
+--echo # Wait for concurrent insert to reach the debug point
+let $wait_condition=
+  SELECT COUNT(*) = 1 FROM INFORMATION_SCHEMA.PROCESSLIST
+  WHERE STATE = "wait_after_query_cache_invalidate" AND
+        INFO = "INSERT INTO t1 VALUES (4)";
+--source include/wait_condition.inc
+
+connection con2;
+--echo # Switch to connection con2
+--echo # Send SELECT that shouldn't be cached
+SELECT * FROM t1;
+
+connection default;
+--echo # Switch to connection default
+--echo # Notify the concurrent insert to proceed
+SELECT ID FROM INFORMATION_SCHEMA.PROCESSLIST
+  WHERE STATE = 'wait_after_query_cache_invalidate' INTO @thread_id;
+KILL QUERY @thread_id;
+
+connection con1;
+--echo # Switch to connection con1
+--echo # Gather insert result
+--reap
+SHOW STATUS LIKE "Qcache_queries_in_cache";
+--echo # Test that it's cacheable
+SELECT * FROM t1;
+SHOW STATUS LIKE "Qcache_queries_in_cache";
+
+--echo # Disconnect
+disconnect con1;
+disconnect con2;
+
+connection default;
+--echo # Restore defaults
+RESET QUERY CACHE;
+DROP TABLE t1,t2;
+SET GLOBAL concurrent_insert= DEFAULT;
+SET GLOBAL query_cache_size= DEFAULT;
+SET GLOBAL query_cache_type= DEFAULT;