From 5f375723216bdf0519316db1d2acf464b80a708f Mon Sep 17 00:00:00 2001
From: Eli Zaretskii <eliz@gnu.org>
Date: Mon, 20 Jun 2016 17:19:25 +0300
Subject: [PATCH] Fix removal of variables from process-environment

* src/callproc.c (add_env): Fix comparison of a variable with a
value against the same variable without a value.  (Bug#23779)
---
 src/callproc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/callproc.c b/src/callproc.c
index db602f538c..2fb5b1d519 100644
--- a/src/callproc.c
+++ b/src/callproc.c
@@ -1099,7 +1099,7 @@ add_env (char **env, char **new_env, char *string)
       char *p = *ep, *q = string;
       while (ok)
 	{
-	  if (*q != *p)
+	  if (*p && *q != *p)
 	    break;
 	  if (*q == 0)
 	    /* The string is a lone variable name; keep it for now, we
-- 
2.39.2