MDEV-12379: Server crashes in TABLE_LIST::is_with_table on SHOW CREATE VIEW

In case of error on opening VIEW (absent table for example) it is still possible to print its definition but some variable is not set (table_list->derived->derived) so it is better do not try to test it when there is safer alternative (table_list itself).

mysql-test/r/view.result

@@ -6466,5 +6466,18 @@ ERROR HY000: Can not modify more than one base table through a join view 'test.v
 drop view v;
 drop table t1,t2,t3;
 #
+# MDEV-12379: Server crashes in TABLE_LIST::is_with_table on
+# SHOW CREATE VIEW
+#
+CREATE TABLE t (i INT);
+CREATE VIEW v AS SELECT * FROM ( SELECT * FROM t ) sq;
+DROP TABLE IF EXISTS t;
+SHOW CREATE VIEW v;
+View	Create View	character_set_client	collation_connection
+v	CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `v` AS select `sq`.`i` AS `i` from (select `test`.`t`.`i` AS `i` from `test`.`t`) `sq`	latin1	latin1_swedish_ci
+Warnings:
+Warning	1356	View 'test.v' references invalid table(s) or column(s) or function(s) or definer/invoker of view lack rights to use them
+DROP VIEW v;
+#
 # End of 10.2 tests
 #

mysql-test/t/view.test

@@ -6186,6 +6186,18 @@ REPLACE INTO v (f1,f2) VALUES (1,1);
 drop view v;
 drop table t1,t2,t3;
 
+
+--echo #
+--echo # MDEV-12379: Server crashes in TABLE_LIST::is_with_table on
+--echo # SHOW CREATE VIEW
+--echo #
+
+CREATE TABLE t (i INT);
+CREATE VIEW v AS SELECT * FROM ( SELECT * FROM t ) sq;
+DROP TABLE IF EXISTS t;
+SHOW CREATE VIEW v;
+DROP VIEW v;
+
 --echo #
 --echo # End of 10.2 tests
 --echo #

sql/sql_select.cc

@@ -25077,7 +25077,7 @@ void TABLE_LIST::print(THD *thd, table_map eliminated_tables, String *str,
     }
     else if (derived)
     {
-      if (!derived->derived->is_with_table())
+      if (!is_with_table())
       {
         // A derived table
         str->append('(');