mysql-5.5.18 merge

1 files changed, 23 insertions, 0 deletions

diff --git a/mysql-test/r/flush.result b/mysql-test/r/flush.result
index 246cd40fd26..340a0863790 100644
--- a/mysql-test/r/flush.result
+++ b/mysql-test/r/flush.result
@@ -466,3 +466,26 @@ ALTER TABLE t1 COMMENT 'test';
 ERROR HY000: Table 't1' was locked with a READ lock and can't be updated
 UNLOCK TABLES;
 DROP TABLE t1;
+#
+# Test for bug #12641342 - "61401: UPDATE PERFORMANCE DEGRADES
+#                           GRADUALLY IF A TRIGGER EXISTS".
+#
+# One of side-effects of this bug was that a transaction which
+# involved DML statements requiring prelocking blocked concurrent
+# FLUSH TABLES WITH READ LOCK for the whole its duration, while
+# correct behavior in this case is to block FTWRL only for duration
+# of individual DML statements.
+DROP TABLE IF EXISTS t1;
+CREATE TABLE t1 (id INT PRIMARY KEY, value INT);
+INSERT INTO t1 VALUES (1, 1);
+CREATE TRIGGER t1_au AFTER UPDATE ON t1 FOR EACH ROW SET @var = "a";
+BEGIN;
+UPDATE t1 SET value= value + 1 WHERE id = 1;
+# Switching to connection 'con1'.
+# The below FLUSH TABLES WITH READ LOCK should succeed and
+# should not be blocked by the transaction in default connection.
+FLUSH TABLES WITH READ LOCK;
+UNLOCK TABLES;
+# Switching to connection 'default'.
+COMMIT;
+DROP TABLE t1;