From: Andreas Gruenbacher <agruen@gnu.org>
Date: Mon, 12 Feb 2018 16:48:24 +0100
Subject: Fix segfault with mangled rename patch
Patch-mainline: yes
Git-commit: f290f48a621867084884bfff87f8093c15195e6a
References: bsc#1080951, CVE-2018-6951, savannah#53133

http://savannah.gnu.org/bugs/?53132
* src/pch.c (intuit_diff_type): Ensure that two filenames are specified
for renames and copies (fix the existing check).

diff --git a/src/pch.c b/src/pch.c
index ff9ed2c..bc6278c 100644
--- a/src/pch.c
+++ b/src/pch.c
@@ -974,7 +974,8 @@ intuit_diff_type (bool need_header, mode_t *p_file_type)
     if ((pch_rename () || pch_copy ())
 	&& ! inname
 	&& ! ((i == OLD || i == NEW) &&
-	      p_name[! reverse] &&
+	      p_name[reverse] && p_name[! reverse] &&
+	      name_is_valid (p_name[reverse]) &&
 	      name_is_valid (p_name[! reverse])))
       {
 	say ("Cannot %s file without two valid file names\n", pch_rename () ? "rename" : "copy");