do not allocate 0 sized buffers which won't be copied/freed after

[simgrid.git] / src / smpi / smpi_base.c

diff --git a/src/smpi/smpi_base.c b/src/smpi/smpi_base.c
index d7d32fc..f5a2192 100644 (file)
--- a/src/smpi/smpi_base.c
+++ b/src/smpi/smpi_base.c
@@ -197,7 +197,7 @@ static MPI_Request build_request(void *buf, int count,
   if(datatype->has_subtype == 1){
     // This part handles the problem of non-contiguous memory
     old_buf = buf;
-    buf = xbt_malloc(count*smpi_datatype_size(datatype));
+    buf = count==0 ? NULL : xbt_malloc(count*smpi_datatype_size(datatype));
     if (flags & SEND) {
       subtype->serialize(old_buf, buf, count, datatype->substruct);
     }
@@ -362,7 +362,7 @@ void smpi_mpi_start(MPI_Request request)
       request->refcount++;
       if(request->old_type->has_subtype == 0){
         oldbuf = request->buf;
-        if (oldbuf){
+        if (oldbuf && request->size!=0){
           request->buf = xbt_malloc(request->size);
           memcpy(request->buf,oldbuf,request->size);
         }