MDEV-10057: Crash with EXPLAIN + WITH + constant query

Add the testcase

mysql-test/r/cte_nonrecursive.result

@@ -851,3 +851,16 @@ a
 9
 drop view v1;
 drop table ten, one_k;
+#
+# MDEV-10057 : Crash with EXPLAIN + WITH + constant query
+#
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (1),(2),(3);
+SELECT * FROM (WITH a AS (SELECT * FROM t1) SELECT 1) AS t1;
+1
+1
+EXPLAIN SELECT * FROM (WITH a AS (SELECT * FROM t1) SELECT 1) AS t1;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	<derived2>	system	NULL	NULL	NULL	NULL	1	
+2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
+DROP TABLE t1;

mysql-test/t/cte_nonrecursive.test

@@ -535,3 +535,12 @@ select * from v1;
 
 drop view v1;
 drop table ten, one_k;
+
+--echo #
+--echo # MDEV-10057 : Crash with EXPLAIN + WITH + constant query
+--echo #
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (1),(2),(3);
+SELECT * FROM (WITH a AS (SELECT * FROM t1) SELECT 1) AS t1;
+EXPLAIN SELECT * FROM (WITH a AS (SELECT * FROM t1) SELECT 1) AS t1;
+DROP TABLE t1;