From 8cd720d608ef06db0a23da1c05845147c2839e29 Mon Sep 17 00:00:00 2001
From: Simon Tatham <anakin@pobox.com>
Date: Sat, 16 Jul 2011 12:03:14 +0000
Subject: [PATCH] Mostly cosmetic change: don't claim to have found an SSH
 agent if SSH_AUTH_SOCK is defined to the empty string. (Because a common way
 to 'unset' it is to run commands like 'SSH_AUTH_SOCK= putty -load thing'.)

[originally from svn r9225]
---
 unix/uxagentc.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/unix/uxagentc.c b/unix/uxagentc.c
index 3605c601..9f579cd9 100644
--- a/unix/uxagentc.c
+++ b/unix/uxagentc.c
@@ -17,7 +17,8 @@
 
 int agent_exists(void)
 {
-    if (getenv("SSH_AUTH_SOCK") != NULL)
+    const char *p = getenv("SSH_AUTH_SOCK");
+    if (p && *p)
 	return TRUE;
     return FALSE;
 }