Bug#33275 Server crash when creating temporary table mysql.user

When creating a temporary table that uses the same name as the mysql
privs table the server would crash on FLUSH PRIVILEGES.

This patches corrects the problem by setting a flag to ignore any
temporary table when trying to reload the privileges.

mysql-test/r/grant.result

@@ -1129,4 +1129,10 @@ DROP USER mysqltest_1@localhost;
 DROP DATABASE db27878;
 use test;
 DROP TABLE t1;
+#
+#  Bug#33275 Server crash when creating temporary table mysql.user
+#
+CREATE TEMPORARY TABLE mysql.user (id INT);
+FLUSH PRIVILEGES;
+DROP TABLE mysql.user;
 End of 5.0 tests

mysql-test/t/grant.test

@@ -1153,4 +1153,11 @@ DROP DATABASE db27878;
 use test;
 DROP TABLE t1;
 
+--echo #
+--echo #  Bug#33275 Server crash when creating temporary table mysql.user
+--echo #
+CREATE TEMPORARY TABLE mysql.user (id INT);
+FLUSH PRIVILEGES;
+DROP TABLE mysql.user;
+
 --echo End of 5.0 tests

sql/sql_acl.cc

@@ -558,6 +558,8 @@ my_bool acl_reload(THD *thd)
   tables[0].next_local= tables[0].next_global= tables+1;
   tables[1].next_local= tables[1].next_global= tables+2;
   tables[0].lock_type=tables[1].lock_type=tables[2].lock_type=TL_READ;
+  tables[0].skip_temporary= tables[1].skip_temporary=
+    tables[2].skip_temporary= TRUE;
 
   if (simple_open_n_lock_tables(thd, tables))
   {
@@ -3528,7 +3530,8 @@ my_bool grant_reload(THD *thd)
   tables[0].next_local= tables[0].next_global= tables+1;
   tables[1].next_local= tables[1].next_global= tables+2;
   tables[0].lock_type= tables[1].lock_type= tables[2].lock_type= TL_READ;
-
+  tables[0].skip_temporary= tables[1].skip_temporary=
+    tables[2].skip_temporary= TRUE;
   /*
     To avoid deadlocks we should obtain table locks before
     obtaining LOCK_grant rwlock.