Fix bug #11416 Server crash if using a view that uses function convert_tz

When parser parses function convert_tz it loads available timezone tables in
thd->lex->time_zone_tables_used. But view have another lex that main query.
Thus time_zone_tables_used of main query left uninitialized.
When Item_func_conver_tz is fixed it takes timezone tables from main query
and later when it executed it assumes that timezone tables are loaded and
failed that assertion.



sql/sql_view.cc:
  Fix bug #11416 Server crash if using a view that uses function convert_tz
mysql-test/r/view.result:
  Test case for bug#11416 Server crash if using a view that uses function convert_tz
mysql-test/t/view.test:
  Test case for bug#11416 Server crash if using a view that uses function convert_tz

mysql-test/r/view.result

@@ -2205,3 +2205,8 @@ select * from (select f1 as f2 from v1) v where v.f2='a';
 f2
 drop view v1;
 drop table t1;
+create view v1 as SELECT CONVERT_TZ('2004-01-01 12:00:00','GMT','MET');
+select * from v1;
+CONVERT_TZ('2004-01-01 12:00:00','GMT','MET')
+NULL
+drop view v1;

mysql-test/t/view.test

@@ -2086,3 +2086,10 @@ create view v1 as select * from t1;
 select * from (select f1 as f2 from v1) v where v.f2='a';
 drop view v1;
 drop table t1;
+
+#
+# Bug #11416 Server crash if using a view that uses function convert_tz
+#
+create view v1 as SELECT CONVERT_TZ('2004-01-01 12:00:00','GMT','MET');
+select * from v1;
+drop view v1;

sql/sql_view.cc

@@ -1069,6 +1069,8 @@ ok:
 ok2:
   if (arena)
     thd->restore_active_arena(arena, &backup);
+  if (!old_lex->time_zone_tables_used && thd->lex->time_zone_tables_used)
+    old_lex->time_zone_tables_used= thd->lex->time_zone_tables_used;
   thd->lex= old_lex;
   DBUG_RETURN(0);