From 370d85c0bc1fd13c8444a243ecd4390012f5c246 Mon Sep 17 00:00:00 2001
From: Frederic Suter <frederic.suter@cc.in2p3.fr>
Date: Thu, 21 Feb 2019 20:29:21 +0100
Subject: [PATCH 1/1] fix some issues with Cancel * Comm::cancel can be called
 when there is no pimpl * if we wait for a canceled activity we can return not
 let the impossible happen.

---
 src/s4u/s4u_Comm.cpp | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/s4u/s4u_Comm.cpp b/src/s4u/s4u_Comm.cpp
index 50eaf00d28..7eb4685229 100644
--- a/src/s4u/s4u_Comm.cpp
+++ b/src/s4u/s4u_Comm.cpp
@@ -167,6 +167,8 @@ Comm* Comm::wait_for(double timeout)
       state_ = State::FINISHED;
       return this;
 
+    case State::CANCELED:
+      return this;
     default:
       THROW_IMPOSSIBLE;
   }
@@ -193,7 +195,10 @@ Comm* Comm::detach()
 
 Comm* Comm::cancel()
 {
-  simgrid::simix::simcall([this] { static_cast<kernel::activity::CommImpl*>(pimpl_.get())->cancel(); });
+  simgrid::simix::simcall([this] {
+    if (pimpl_)
+      boost::static_pointer_cast<kernel::activity::CommImpl>(pimpl_)->cancel();
+  });
   state_ = State::CANCELED;
   return this;
 }
-- 
2.20.1