Added a test case for Bug#18038 MySQL server corrupts binary columns data

mysql-test/r/alter_table.result

@@ -621,3 +621,23 @@ create table t1 (t varchar(255) default null, key t (t(80)))
 engine=myisam default charset=latin1;
 alter table t1 change t t text;
 drop table t1;
+CREATE TABLE t1 (s CHAR(8) BINARY);
+INSERT INTO t1 VALUES ('test');
+SELECT LENGTH(s) FROM t1;
+LENGTH(s)
+4
+ALTER TABLE t1 MODIFY s CHAR(10) BINARY;
+SELECT LENGTH(s) FROM t1;
+LENGTH(s)
+4
+DROP TABLE t1;
+CREATE TABLE t1 (s BINARY(8));
+INSERT INTO t1 VALUES ('test');
+SELECT LENGTH(s) FROM t1;
+LENGTH(s)
+8
+ALTER TABLE t1 MODIFY s BINARY(10);
+SELECT LENGTH(s) FROM t1;
+LENGTH(s)
+10
+DROP TABLE t1;

mysql-test/t/alter_table.test

@@ -449,3 +449,21 @@ create table t1 (t varchar(255) default null, key t (t(80)))
 engine=myisam default charset=latin1;
 alter table t1 change t t text;
 drop table t1;
+
+#
+# Bug#18038  MySQL server corrupts binary columns data
+#
+
+CREATE TABLE t1 (s CHAR(8) BINARY);
+INSERT INTO t1 VALUES ('test');
+SELECT LENGTH(s) FROM t1;
+ALTER TABLE t1 MODIFY s CHAR(10) BINARY;
+SELECT LENGTH(s) FROM t1;
+DROP TABLE t1;
+
+CREATE TABLE t1 (s BINARY(8));
+INSERT INTO t1 VALUES ('test');
+SELECT LENGTH(s) FROM t1;
+ALTER TABLE t1 MODIFY s BINARY(10);
+SELECT LENGTH(s) FROM t1;
+DROP TABLE t1;