MDEV-28393 Server crashes in TABLE::mark_default_fields_for_write

test only

mysql-test/r/create_select.result

@@ -24,3 +24,14 @@ drop table t1;
 #
 # End of 4.1 tests
 #
+#
+# MDEV-28393 Server crashes in TABLE::mark_default_fields_for_write
+#
+create table t1 (a int, b text not null default '');
+alter table t1 character set = utf8;
+create table t2 select * from t1;
+insert into t1 values (1,'');
+drop table t1, t2;
+#
+# End of 10.2 tests
+#

mysql-test/t/create_select.test

@@ -37,3 +37,16 @@ drop table t1;
 --echo #
 --echo # End of 4.1 tests
 --echo #
+
+--echo #
+--echo # MDEV-28393 Server crashes in TABLE::mark_default_fields_for_write
+--echo #
+create table t1 (a int, b text not null default '');
+alter table t1 character set = utf8;
+create table t2 select * from t1;
+insert into t1 values (1,'');
+drop table t1, t2;
+
+--echo #
+--echo # End of 10.2 tests
+--echo #