backport branches/starpu-1.1@13968: mpi/src/starpu_mpi.c: fix starpu_mpi_data_register to check a data has a valid home node only on the node it belongs to

mpi/src/starpu_mpi.c

@@ -1431,10 +1431,13 @@ void _starpu_mpi_clear_cache(starpu_data_handle_t data_handle)
 
 void starpu_mpi_data_register(starpu_data_handle_t data_handle, int tag, int rank)
 {
+	int my;
+	MPI_Comm_rank(MPI_COMM_WORLD, &my);
+	if (my != rank)
+		STARPU_ASSERT_MSG(data_handle->home_node == -1, "Data does not belong to node %d, it should be assigned a home node -1", my);
 	_starpu_data_set_rank(data_handle, rank);
 	_starpu_data_set_tag(data_handle, tag);
 	_starpu_data_set_unregister_hook(data_handle, _starpu_mpi_clear_cache);
-
 }
 
 int starpu_mpi_world_rank(void)