From 516a0ad46448cd7f622808f8fd07d97191cbb131 Mon Sep 17 00:00:00 2001
From: Neeraj Bisht <neeraj.x.bisht@oracle.com>
Date: Tue, 29 Jan 2013 10:05:00 +0530
Subject: [PATCH] Bug#16208709 - CRASH IN GET_SEL_ARG_FOR_KEYPART ON SELECT
 DISTINCT 	       ON COL WITH COMPOSITE INDEX

This problem is caused by the patch for the bug#11751794.
While checking for the keypart covering non grouping attribute. we are not
checking whether the root node of the SEL_ARG* tree for the index have any
cvalue or not.
---
 sql/opt_range.cc | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/sql/opt_range.cc b/sql/opt_range.cc
index 4e67727462c..ae6878c6756 100644
--- a/sql/opt_range.cc
+++ b/sql/opt_range.cc
@@ -9870,6 +9870,8 @@ get_sel_arg_for_keypart(Field *nga_field,
                         SEL_ARG *keypart_tree,
                         SEL_ARG **cur_range)
 {
+  if(keypart_tree == NULL)
+    return false;
   if(keypart_tree->field->eq(nga_field))
   {
     /*