Fix for BUG#40827 - Killing insert-select to MyISAM can cause table corruption

                       
Killing the insert-select statement corrupts the MyISAM table only
when the destination table is empty and when it has indexes. When 
we bulk insert huge data and if the destination table is empty we 
disable the indexes for fast inserts, data is then inserted and 
indexes are re-enabled after bulk_insert operation
                        
Killing the query, aborts the repair table operation during enable
indexes phase leading to table corruption.
                      
We now truncate the table when we detect that enable indexes is
killed for bulk insert query.As we have an empty table before the 
operation, we can fix by truncating the table.

mysql-test/r/myisam.result:
  Result file for BUG#40827
mysql-test/t/myisam.test:
  Testcase for BUG#40827
storage/myisam/ha_myisam.cc:
  Fixed end_bulk_insert() method to truncate the table when we detect enable 
  index operation is killed.

1 files changed, 39 insertions, 0 deletions

diff --git a/mysql-test/r/myisam.result b/mysql-test/r/myisam.result
index 732b1b260f8..c3eede79754 100644
--- a/mysql-test/r/myisam.result
+++ b/mysql-test/r/myisam.result
@@ -2252,4 +2252,43 @@ h+0	d + 0	e	g + 0
 1	1	3	0
 1	1	4	0
 DROP TABLE t1;
+#
+# BUG#40827 - Killing insert-select to MyISAM can cause table corruption
+#
+CREATE TABLE `t1` (
+`id` BIGINT(20) ,
+`id1` BIGINT(20) AUTO_INCREMENT,
+KEY(id1), KEY(id)
+) ENGINE=MyISAM;
+CREATE TABLE `t2` (
+`id` BIGINT(20) ,
+`id1` BIGINT(20) AUTO_INCREMENT,
+KEY (id1), KEY(id)
+) ENGINE=MyISAM;
+INSERT INTO t2 (id) VALUES (123);
+INSERT INTO t2 (id) SELECT id  FROM t2;
+INSERT INTO t2 (id) SELECT id  FROM t2;
+INSERT INTO t2 (id) SELECT id  FROM t2;
+INSERT INTO t2 (id) SELECT id  FROM t2;
+INSERT INTO t2 (id) SELECT id  FROM t2;
+INSERT INTO t2 (id) SELECT id  FROM t2;
+INSERT INTO t2 (id) SELECT id  FROM t2;
+INSERT INTO t2 (id) SELECT id  FROM t2;
+INSERT INTO t2 (id) SELECT id  FROM t2;
+INSERT INTO t2 (id) SELECT id  FROM t2;
+# Switch to insert Connection
+SET SESSION debug='+d,wait_in_enable_indexes';
+# Send insert data
+INSERT INTO t1(id) SELECT id  FROM t2;
+# Switch to default Connection
+# Wait for insert data to reach the debug point
+SELECT ID FROM INFORMATION_SCHEMA.PROCESSLIST
+WHERE STATE = 'wait_in_enable_indexes' AND 
+INFO = "INSERT INTO t1(id) SELECT id  FROM t2" 
+INTO @thread_id;
+KILL QUERY @thread_id;
+CHECK TABLE t1;
+Table	Op	Msg_type	Msg_text
+test.t1	check	status	OK
+DROP TABLE t1,t2;
 End of 5.1 tests