Merge branch '5.5' into 10.0

4 files changed, 33 insertions, 3 deletions

diff --git a/debian/control b/debian/control
index 6bad46542d6..862cd4f3cea 100644
--- a/debian/control
+++ b/debian/control
@@ -24,8 +24,8 @@ Build-Depends: bison,
                ${LIBREADLINE_DEV}
 Standards-Version: 3.8.3
 Homepage: http://mariadb.org/
-Vcs-Browser: http://bazaar.launchpad.net/~maria-captains/maria/10.0/files
-Vcs-Bzr: bzr://lp:maria
+Vcs-Browser: https://github.com/MariaDB/server/
+Vcs-Git: https://github.com/MariaDB/server.git
 
 Package: libmariadbclient18
 Section: libs
diff --git a/mysql-test/r/subselect_mat.result b/mysql-test/r/subselect_mat.result
index db51bbb8186..ff09da022b4 100644
--- a/mysql-test/r/subselect_mat.result
+++ b/mysql-test/r/subselect_mat.result
@@ -2714,3 +2714,18 @@ a	b	sq
 4	4	1
 4	2	1
 drop table t1, t2;
+#
+# MDEV-15235: Assertion `length > 0' failed in create_ref_for_key
+#
+CREATE TABLE t1 (i INT);
+INSERT INTO t1 VALUES (1),(2);
+CREATE TABLE t2 (f CHAR(1));
+INSERT INTO t2 VALUES ('a'),('b');
+explain
+SELECT * FROM t2 WHERE f IN ( SELECT LEFT('foo',0) FROM t1 ORDER BY 1 );
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	Using where
+2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	
+SELECT * FROM t2 WHERE f IN ( SELECT LEFT('foo',0) FROM t1 ORDER BY 1 );
+f
+DROP TABLE t1, t2;
diff --git a/mysql-test/t/subselect_mat.test b/mysql-test/t/subselect_mat.test
index 09c6b3e1747..5211f35b48b 100644
--- a/mysql-test/t/subselect_mat.test
+++ b/mysql-test/t/subselect_mat.test
@@ -254,3 +254,16 @@ SELECT a, b, (a, b) NOT IN (SELECT a, b FROM t2) as sq
 FROM t1;
 
 drop table t1, t2;
+
+--echo #
+--echo # MDEV-15235: Assertion `length > 0' failed in create_ref_for_key
+--echo #
+
+CREATE TABLE t1 (i INT);
+INSERT INTO t1 VALUES (1),(2);
+CREATE TABLE t2 (f CHAR(1));
+INSERT INTO t2 VALUES ('a'),('b');
+explain
+SELECT * FROM t2 WHERE f IN ( SELECT LEFT('foo',0) FROM t1 ORDER BY 1 );
+SELECT * FROM t2 WHERE f IN ( SELECT LEFT('foo',0) FROM t1 ORDER BY 1 );
+DROP TABLE t1, t2;
diff --git a/sql/opt_subselect.cc b/sql/opt_subselect.cc
index 67205a52cac..8aa04c62f42 100644
--- a/sql/opt_subselect.cc
+++ b/sql/opt_subselect.cc
@@ -873,8 +873,10 @@ bool subquery_types_allow_materialization(Item_in_subselect *in_subs)
      Make sure that create_tmp_table will not fail due to too long keys.
      See MDEV-7122. This check is performed inside create_tmp_table also and
      we must do it so that we know the table has keys created.
+     Make sure that the length of the key for the temp_table is atleast
+     greater than 0.
   */
-  if (total_key_length > tmp_table_max_key_length() ||
+  if (!total_key_length || total_key_length > tmp_table_max_key_length() ||
       elements > tmp_table_max_key_parts())
     DBUG_RETURN(FALSE);