X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/4c96d3eadaf5c03fae80c4f0b0a12907609aee11..d302816d682e544d2ec520f5844cfd271137296a:/src/smpi/colls/smpi_default_selector.cpp

diff --git a/src/smpi/colls/smpi_default_selector.cpp b/src/smpi/colls/smpi_default_selector.cpp
index d3736cc81b..f218a4efcb 100644
--- a/src/smpi/colls/smpi_default_selector.cpp
+++ b/src/smpi/colls/smpi_default_selector.cpp
@@ -213,6 +213,8 @@ int Coll_reduce_default::reduce(void *sendbuf, void *recvbuf, int count, MPI_Dat
 
   int rank = comm->rank();
   int size = comm->size();
+  if(size==0)
+    return MPI_ERR_COMM;
   //non commutative case, use a working algo from openmpi
   if (op != MPI_OP_NULL && not op->is_commutative()) {
     return Coll_reduce_ompi_basic_linear::reduce(sendtmpbuf, recvbuf, count, datatype, op, root, comm);