From f263c6014e4e5c66fb6aa1a6aa8d67d2d105ea52 Mon Sep 17 00:00:00 2001
From: "Vicente J. Botet Escriba" <vicente.botet@wanadoo.fr>
Date: Sun, 6 Jul 2014 18:47:48 +0200
Subject: [PATCH] fix wait_pull_front in case the queue is closed while empty.

---
 include/boost/thread/sync_queue.hpp | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/include/boost/thread/sync_queue.hpp b/include/boost/thread/sync_queue.hpp
index 8e4bc93c..489cd252 100644
--- a/include/boost/thread/sync_queue.hpp
+++ b/include/boost/thread/sync_queue.hpp
@@ -320,7 +320,9 @@ namespace boost
     {
       if (closed(lk)) return queue_op_status::closed;
     }
-    wait_until_not_empty(lk);
+    bool has_been_closed = false;
+    wait_until_not_empty(lk, has_been_closed);
+    if (has_been_closed) return queue_op_status::closed;
     pull_front(elem, lk);
     return queue_op_status::success;
   }