From: Augustin Degomme <adegomme@users.noreply.github.com>
Date: Sat, 6 Apr 2019 12:54:02 +0000 (+0200)
Subject: please herr sonar
X-Git-Tag: v3.22.2~163^2
X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/commitdiff_plain/6cf57242a375fb0186c9eefcf46fcff848d54b19?hp=a4129e0f81724054c885e3242f05996ffa9d501b

please herr sonar
---

diff --git a/src/smpi/bindings/smpi_pmpi_coll.cpp b/src/smpi/bindings/smpi_pmpi_coll.cpp
index c4f8183dca..2eb62c2c09 100644
--- a/src/smpi/bindings/smpi_pmpi_coll.cpp
+++ b/src/smpi/bindings/smpi_pmpi_coll.cpp
@@ -760,7 +760,9 @@ int PMPI_Ialltoall(void* sendbuf, int sendcount, MPI_Datatype sendtype, void* re
     MPI_Datatype sendtmptype = sendtype;
     if (sendbuf == MPI_IN_PLACE) {
       sendtmpbuf = static_cast<void*>(xbt_malloc(recvcount * comm->size() * recvtype->size()));
-      memcpy(sendtmpbuf, recvbuf, recvcount * comm->size() * recvtype->size());
+      //memcpy(??,nullptr,0) is actually undefined behavor, even if harmless.
+      if(recvbuf != nullptr)
+        memcpy(sendtmpbuf, recvbuf, recvcount * comm->size() * recvtype->size());
       sendtmpcount = recvcount;
       sendtmptype  = recvtype;
     }