Additional tweak to fix for bug #10543, to prevent a change in

behavior when extending fields that were fully part of a
multi-part key.


mysql-test/r/key.result:
  Update results
mysql-test/t/key.test:
  Add test for behavior of extending fields in a multi-part key
  that were defined with a partial length the same as their
  field length.
sql/sql_table.cc:
  Reset key_part_length when old field length was the same as the
  old key_part_length.

1 files changed, 13 insertions, 0 deletions

diff --git a/mysql-test/t/key.test b/mysql-test/t/key.test
index af3509c8454..9db1523be51 100644
--- a/mysql-test/t/key.test
+++ b/mysql-test/t/key.test
@@ -324,3 +324,16 @@ alter table t1 add key (c1,c2,c1);
 --error 1060
 alter table t1 add key (c1,c1,c2);
 drop table t1;
+
+#
+# If we use a partial field for a key that is actually the length of the
+# field, and we extend the field, we end up with a key that includes the
+# whole new length of the field.
+#
+create table t1 (a varchar(10), b varchar(10), key(a(10),b(10)));
+show create table t1;
+alter table t1 modify b varchar(20);
+show create table t1;
+alter table t1 modify a varchar(20);
+show create table t1;
+drop table t1;