1 files changed, 46 insertions, 0 deletions
diff --git a/mysql-test/suite/innodb/r/instant_alter_purge.result b/mysql-test/suite/innodb/r/instant_alter_purge.result
new file mode 100644
index 00000000000..a3643610f04
--- /dev/null
+++ b/mysql-test/suite/innodb/r/instant_alter_purge.result
@@ -0,0 +1,46 @@
+SET @saved_frequency = @@GLOBAL.innodb_purge_rseg_truncate_frequency;
+SET GLOBAL innodb_purge_rseg_truncate_frequency=1;
+#
+# MDEV-17793 Crash in purge after instant DROP and emptying the table
+#
+connect  prevent_purge,localhost,root;
+START TRANSACTION WITH CONSISTENT SNAPSHOT;
+connection default;
+CREATE TABLE t1 (f1 INT, f2 INT) ENGINE=InnoDB;
+INSERT INTO t1 () VALUES ();
+ALTER TABLE t1 DROP f2, ADD COLUMN f2 INT;
+ALTER TABLE t1 DROP f1;
+DELETE FROM t1;
+connection prevent_purge;
+COMMIT;
+START TRANSACTION WITH CONSISTENT SNAPSHOT;
+connection default;
+ALTER TABLE t1 ADD COLUMN extra TINYINT UNSIGNED NOT NULL DEFAULT 42;
+InnoDB		1 transactions not purged
+ALTER TABLE t1 DROP extra;
+disconnect prevent_purge;
+InnoDB		0 transactions not purged
+DROP TABLE t1;
+#
+# MDEV-17813 Crash in instant ALTER TABLE due to purge
+# concurrently emptying table
+#
+CREATE TABLE t1 (f2 INT) ENGINE=InnoDB;
+INSERT INTO t1 SET f2=1;
+ALTER TABLE t1 ADD COLUMN f1 INT;
+connect  purge_control,localhost,root;
+START TRANSACTION WITH CONSISTENT SNAPSHOT;
+connection default;
+DELETE FROM t1;
+SET DEBUG_SYNC='innodb_commit_inplace_alter_table_enter SIGNAL go WAIT_FOR do';
+ALTER TABLE t1 ADD COLUMN f3 INT;
+connection purge_control;
+SET DEBUG_SYNC='now WAIT_FOR go';
+COMMIT;
+InnoDB		0 transactions not purged
+SET DEBUG_SYNC='now SIGNAL do';
+disconnect purge_control;
+connection default;
+SET DEBUG_SYNC=RESET;
+DROP TABLE t1;
+SET GLOBAL innodb_purge_rseg_truncate_frequency = @saved_frequency;