A patch for Bug#12429877: QUERY_TABLES_LIST::SROUTINES IS NOT

FREED IN FLUSH_READ_LOCK (VALGRIND WARNING).

The problem was that under some circustances the memory allocated
for Query_tables_list::sroutines was not freed properly.
The cause of this problem was the absence of
LEX::restore_backup_query_tables_list() call in one of the branches
in mysql_table_grant() function.

sql/sql_acl.cc

@@ -3644,6 +3644,7 @@ int mysql_table_grant(THD *thd, TABLE_LIST *table_list,
   {						// Should never happen
     /* Restore the state of binlog format */
     DBUG_ASSERT(!thd->is_current_stmt_binlog_format_row());
+    thd->lex->restore_backup_query_tables_list(&backup);
     if (save_binlog_row_based)
       thd->set_current_stmt_binlog_format_row();
     DBUG_RETURN(TRUE);				/* purecov: deadcode */