From df3d5e44a868b07107aba9bf07683d8fdb95a6d8 Mon Sep 17 00:00:00 2001
From: Martin Quinson <martin.quinson@loria.fr>
Date: Sat, 23 Apr 2016 09:57:18 +0200
Subject: [PATCH] Calling front() on empty deque is undefined

- MSG_mailbox_is_empty supposes that it returns nullptr
---
 src/simix/smx_network.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/simix/smx_network.cpp b/src/simix/smx_network.cpp
index f2076abefa..dcf2c73eb2 100644
--- a/src/simix/smx_network.cpp
+++ b/src/simix/smx_network.cpp
@@ -70,7 +70,7 @@ smx_mailbox_t SIMIX_mbox_get_by_name(const char *name)
 
 smx_synchro_t SIMIX_mbox_get_head(smx_mailbox_t mbox)
 {
-  return mbox->comm_queue->front();
+  return mbox->comm_queue->empty()? nullptr:mbox->comm_queue->front();
 }
 
 /**
-- 
2.20.1