From 94943bab3b23ca19e39e4cd65ef59ece93461c2c Mon Sep 17 00:00:00 2001
From: Jim Hague <jim.hague@acm.org>
Date: Wed, 17 Sep 2014 17:21:44 +0100
Subject: [PATCH] Fix hang terminating PGM ZMQ_SUB (#822).

---
 src/pgm_receiver.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/pgm_receiver.cpp b/src/pgm_receiver.cpp
index 2a9dc8b6..c556368b 100644
--- a/src/pgm_receiver.cpp
+++ b/src/pgm_receiver.cpp
@@ -288,7 +288,7 @@ void zmq::pgm_receiver_t::drop_subscriptions ()
 {
     msg_t msg;
     msg.init ();
-    while (session->pull_msg (&msg))
+    while (session->pull_msg (&msg) == 0)
         msg.close ();
 }