upstream commit

allow setting IdentityAgent to SSH_AUTH_SOCK; ok djm@

Upstream-ID: 20c508480d8db3eef18942c0fc39b1fcf25652ac
diff --git a/readconf.c b/readconf.c
index 26436b3..c706fbf 100644
--- a/readconf.c
+++ b/readconf.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: readconf.c,v 1.253 2016/05/04 12:21:53 markus Exp $ */
+/* $OpenBSD: readconf.c,v 1.254 2016/05/04 14:29:58 markus Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -2034,6 +2034,7 @@
 	CLEAR_ON_NONE(options->proxy_command);
 	CLEAR_ON_NONE(options->control_path);
 	CLEAR_ON_NONE(options->revoked_host_keys);
+	/* options->identity_agent distinguishes NULL from 'none' */
 	/* options->user will be set in the main program if appropriate */
 	/* options->hostname will be set in the main program if appropriate */
 	/* options->host_key_alias should not be set by default */