From 8a8cca2865222686c0ad4336220673f6be8eb14c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marko=20M=C3=A4kel=C3=A4?= <marko.makela@mariadb.com>
Date: Fri, 1 Sep 2017 12:45:33 +0300
Subject: Fix a buffer overflow in INFORMATION_SCHEMA.GLOBAL_VARIABLES, caused
 by MDEV-12179

pretty_print_engine_list(): When the plugin list is empty, return
an empty string instead of allocating a buffer of 0 bytes and then
trying to write a NUL byte into it.
---
 sql/set_var.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'sql/set_var.cc')

diff --git a/sql/set_var.cc b/sql/set_var.cc
index 606f9ac511d..311b33bc0dd 100644
--- a/sql/set_var.cc
+++ b/sql/set_var.cc
@@ -1483,7 +1483,7 @@ pretty_print_engine_list(THD *thd, plugin_ref *list)
   size_t size;
   char *buf, *pos;
 
-  if (!list)
+  if (!list || !*list)
     return thd->strmake("", 0);
 
   size= 0;
-- 
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