From abf00fc34612f6cc7eded3913237d2a0ce977d7b Mon Sep 17 00:00:00 2001
From: crazycs <crazycs520@gmail.com>
Date: Tue, 8 Jan 2019 16:18:05 +0800
Subject: [PATCH] sessionctx/variable: fix select variable return wrong result
 when variable is only global scope variable (#8968)