Bug#22413 EXPLAIN SELECT FROM view with ORDER BY yield server crash

disable filling of I_S tables for EXPLAIN


mysql-test/r/information_schema.result:
  Bug#22413 EXPLAIN SELECT FROM view with ORDER BY yield server crash
  test case
mysql-test/t/information_schema.test:
  Bug#22413 EXPLAIN SELECT FROM view with ORDER BY yield server crash
  test case

mysql-test/r/information_schema.result

@@ -1254,3 +1254,18 @@ COLUMN_NAME	MD5(COLUMN_DEFAULT)	LENGTH(COLUMN_DEFAULT)	COLUMN_DEFAULT=get_value(
 fld1	7cf7a6782be951a1f2464a350da926a5	65532	1
 DROP TABLE bug23037;
 DROP FUNCTION get_value;
+create view v1 as
+select table_schema as object_schema,
+table_name   as object_name,
+table_type   as object_type
+from information_schema.tables
+order by object_schema;
+explain select * from v1;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	<derived2>	system	NULL	NULL	NULL	NULL	0	const row not found
+2	DERIVED	tables	ALL	NULL	NULL	NULL	NULL	2	Using filesort
+explain select * from (select table_name from information_schema.tables) as a;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	<derived2>	system	NULL	NULL	NULL	NULL	0	const row not found
+2	DERIVED	tables	ALL	NULL	NULL	NULL	NULL	2	
+drop view v1;

mysql-test/t/information_schema.test

@@ -973,4 +973,18 @@ DROP FUNCTION get_value;
 
 
 
+
+#
+# Bug#22413: EXPLAIN SELECT FROM view with ORDER BY yield server crash
+#
+create view v1 as
+select table_schema as object_schema,
+       table_name   as object_name,
+       table_type   as object_type
+from information_schema.tables
+order by object_schema;
+explain select * from v1;
+explain select * from (select table_name from information_schema.tables) as a;
+drop view v1;
+
 # End of 5.0 tests.

sql/sql_select.cc

@@ -1471,6 +1471,7 @@ JOIN::exec()
   curr_join->examined_rows= 0;
 
   if ((curr_join->select_lex->options & OPTION_SCHEMA_TABLE) &&
+      !thd->lex->describe &&
       get_schema_tables_result(curr_join))
   {
     DBUG_VOID_RETURN;
@@ -12278,6 +12279,7 @@ create_sort_index(THD *thd, JOIN *join, ORDER *order,
 
   /* Fill schema tables with data before filesort if it's necessary */
   if ((join->select_lex->options & OPTION_SCHEMA_TABLE) &&
+      !thd->lex->describe &&
       get_schema_tables_result(join))
     goto err;