1 files changed, 47 insertions, 0 deletions
diff --git a/mysql-test/t/myisampack.test b/mysql-test/t/myisampack.test
index afa417822e6..cc9429a1707 100644
--- a/mysql-test/t/myisampack.test
+++ b/mysql-test/t/myisampack.test
@@ -267,3 +267,50 @@ FLUSH TABLE t1;
 --exec $MYISAMCHK -soq $MYSQLD_DATADIR/test/t1
 CHECK TABLE t1;
 DROP TABLE t1;
+
+#
+# MDEV-6245 Certain compressed tables with myisampack are corrupted by
+# "CHECK TABLE"
+#
+# Issue was that checksum failed for tables with NULL and VARCHAR fields
+#
+
+create table `t1` (`id` varchar(15) DEFAULT NULL) ENGINE=MyISAM ROW_FORMAT=FIXED;
+insert into t1 values ('aaa'),('bbb'),('ccc'),('ddd'),('eee');
+insert into t1 (select * from t1);
+insert into t1 (select * from t1);
+insert into t1 (select * from t1);
+insert into t1 (select * from t1);
+checksum table t1;
+insert into t1 values(NULL);
+checksum table t1;
+flush table t1;
+--exec $MYISAMPACK -sf $MYSQLD_DATADIR/test/t1
+--exec $MYISAMCHK -srnq $MYSQLD_DATADIR/test/t1
+check table t1;
+checksum table t1;
+alter table t1 checksum=1 row_format=fixed;
+checksum table t1;
+flush table t1;
+--exec $MYISAMPACK -sf $MYSQLD_DATADIR/test/t1
+--exec $MYISAMCHK -srnq $MYSQLD_DATADIR/test/t1
+check table t1;
+checksum table t1;
+
+# Testing with row_format=dynamic
+
+alter table t1 row_format=dynamic checksum=0;
+checksum table t1;
+flush table t1;
+--exec $MYISAMPACK -sf $MYSQLD_DATADIR/test/t1
+--exec $MYISAMCHK -srnq $MYSQLD_DATADIR/test/t1
+check table t1;
+checksum table t1;
+alter table t1 checksum=1 row_format=dynamic;
+checksum table t1;
+flush table t1;
+--exec $MYISAMPACK -sf $MYSQLD_DATADIR/test/t1
+--exec $MYISAMCHK -srnq $MYSQLD_DATADIR/test/t1
+check table t1;
+checksum table t1;
+drop table t1;