A test for character conversion in ALTER TABLE was added

mysql-test/r/alter_table.result

@@ -281,3 +281,42 @@ ALTER TABLE t1 DISABLE KEYS;
 INSERT DELAYED INTO t1 VALUES(1),(2),(3);
 ALTER TABLE t1 ENABLE KEYS;
 drop table t1;
+set names koi8r;
+create table t1 (a char(10) character set koi8r);
+insert into t1 values ('');
+select a,hex(a) from t1;
+a	hex(a)
+	D4C5D3D4
+alter table t1 change a a char(10) character set cp1251;
+select a,hex(a) from t1;
+a	hex(a)
+	F2E5F1F2
+alter table t1 change a a char(10) binary;
+select a,hex(a) from t1;
+a	hex(a)
+	F2E5F1F2
+alter table t1 change a a char(10) character set cp1251;
+select a,hex(a) from t1;
+a	hex(a)
+	F2E5F1F2
+alter table t1 change a a char(10) character set koi8r;
+select a,hex(a) from t1;
+a	hex(a)
+	D4C5D3D4
+alter table t1 change a a varchar(10) character set cp1251;
+select a,hex(a) from t1;
+a	hex(a)
+	F2E5F1F2
+alter table t1 change a a char(10) character set koi8r;
+select a,hex(a) from t1;
+a	hex(a)
+	D4C5D3D4
+alter table t1 change a a text character set cp1251;
+select a,hex(a) from t1;
+a	hex(a)
+	F2E5F1F2
+alter table t1 change a a char(10) character set koi8r;
+select a,hex(a) from t1;
+a	hex(a)
+	D4C5D3D4
+drop table t1;

mysql-test/t/alter_table.test

@@ -144,3 +144,30 @@ ALTER TABLE t1 DISABLE KEYS;
 INSERT DELAYED INTO t1 VALUES(1),(2),(3);
 ALTER TABLE t1 ENABLE KEYS;
 drop table t1;
+
+#
+# Test that data get converted when character set is changed
+# Test that data doesn't get converted when src or dst is BINARY/BLOB
+#
+set names koi8r;
+create table t1 (a char(10) character set koi8r);
+insert into t1 values ('');
+select a,hex(a) from t1;
+alter table t1 change a a char(10) character set cp1251;
+select a,hex(a) from t1;
+alter table t1 change a a char(10) binary;
+select a,hex(a) from t1;
+alter table t1 change a a char(10) character set cp1251;
+select a,hex(a) from t1;
+alter table t1 change a a char(10) character set koi8r;
+select a,hex(a) from t1;
+alter table t1 change a a varchar(10) character set cp1251;
+select a,hex(a) from t1;
+alter table t1 change a a char(10) character set koi8r;
+select a,hex(a) from t1;
+alter table t1 change a a text character set cp1251;
+select a,hex(a) from t1;
+alter table t1 change a a char(10) character set koi8r;
+select a,hex(a) from t1;
+
+drop table t1;