upstream commit

Fix math error in remote window calculations that causes
 eventual stalls for datagram channels. Reported by Georg Wicherski, ok
 markus@

Upstream-ID: be54059d11bf64e0d85061f7257f53067842e2ab
diff --git a/channels.c b/channels.c
index 45e1f9f..8069cf1 100644
--- a/channels.c
+++ b/channels.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: channels.c,v 1.344 2015/06/05 15:13:13 millert Exp $ */
+/* $OpenBSD: channels.c,v 1.345 2015/06/30 05:23:25 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -2270,7 +2270,7 @@
 					packet_put_int(c->remote_id);
 					packet_put_string(data, dlen);
 					packet_send();
-					c->remote_window -= dlen + 4;
+					c->remote_window -= dlen;
 					free(data);
 				}
 				continue;