1 files changed, 13 insertions, 0 deletions
diff --git a/mysql-test/t/myisam_debug.test b/mysql-test/t/myisam_debug.test
index b106ecdea5e..465ecd70895 100644
--- a/mysql-test/t/myisam_debug.test
+++ b/mysql-test/t/myisam_debug.test
@@ -57,3 +57,16 @@ KILL QUERY @thread_id;
 CHECK TABLE t1; 
 DROP TABLE t1,t2;
 DISCONNECT insertConn;
+
+#
+# MDEV-12761 Error return from external_lock make the server crash
+#
+call mtr.add_suppression("Index for table '.*test.t1\\.MYI' is corrupt; try to repair it");
+create table t1 (a int, index(a));
+lock tables t1 write;
+insert t1 values (1),(2),(1);
+set @old_dbug=@@debug_dbug;
+set debug_dbug='+d,mi_lock_database_failure';
+unlock tables;
+set debug_dbug=@old_dbug;
+drop table t1;