From: Timo Heister <timo.heister@gmail.com>
Date: Thu, 25 Feb 2016 17:21:49 +0000 (-0500)
Subject: fix incorrect MPI_Allgather
X-Git-Tag: v8.4.0-rc3~6^2
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9b39de6ff258509e48a1194145ad522d8af64d55;p=dealii.git

fix incorrect MPI_Allgather

MPI_Allgather in compute_local_to_global_vertex_index_map() was using
the wrong data type, which probably lead to wrong results or at least
illegal memory access.
---

diff --git a/source/grid/grid_tools.cc b/source/grid/grid_tools.cc
index eb61d2164c..eabb5ff310 100644
--- a/source/grid/grid_tools.cc
+++ b/source/grid/grid_tools.cc
@@ -1714,8 +1714,8 @@ next_cell:
     // processors and shifting the indices accordingly
     const unsigned int n_cpu = Utilities::MPI::n_mpi_processes(triangulation.get_communicator());
     std::vector<types::global_vertex_index> indices(n_cpu);
-    MPI_Allgather(&next_index, 1, MPI_UNSIGNED_LONG_LONG, &indices[0],
-                  indices.size(), MPI_UNSIGNED_LONG_LONG, triangulation.get_communicator());
+    MPI_Allgather(&next_index, 1, DEAL_II_DOF_INDEX_MPI_TYPE, &indices[0],
+                  indices.size(), DEAL_II_DOF_INDEX_MPI_TYPE, triangulation.get_communicator());
     const types::global_vertex_index shift = std::accumulate(&indices[0],
                                                              &indices[0]+triangulation.locally_owned_subdomain(),0);