From: Peter Munch <peterrmuench@gmail.com>
Date: Mon, 6 Sep 2021 13:58:05 +0000 (+0200)
Subject: Fix MGTransferGlobalCoarsening::copy_to_mg()
X-Git-Tag: v9.4.0-rc1~999^2
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=refs%2Fpull%2F12745%2Fhead;p=dealii.git

Fix MGTransferGlobalCoarsening::copy_to_mg()
---

diff --git a/include/deal.II/multigrid/mg_transfer_global_coarsening.h b/include/deal.II/multigrid/mg_transfer_global_coarsening.h
index 64bbd4aa1e..d59f1dddd9 100644
--- a/include/deal.II/multigrid/mg_transfer_global_coarsening.h
+++ b/include/deal.II/multigrid/mg_transfer_global_coarsening.h
@@ -608,9 +608,14 @@ MGTransferGlobalCoarsening<dim, VectorType>::copy_to_mg(
       "MGTransferGlobalCoarsening."));
 
   for (unsigned int level = dst.min_level(); level <= dst.max_level(); ++level)
-    initialize_dof_vector(level, dst[level]);
-
-  dst[dst.max_level()].copy_locally_owned_data_from(src);
+    {
+      initialize_dof_vector(level, dst[level]);
+
+      if (level == dst.max_level())
+        dst[level].copy_locally_owned_data_from(src);
+      else
+        dst[level] = 0.0;
+    }
 }