From: Daniel Arndt <arndtd@ornl.gov>
Date: Fri, 5 Jun 2020 16:32:06 +0000 (-0400)
Subject: Fix IndexSet::is_ascending_and_one_to_one for empty objects
X-Git-Tag: v9.3.0-rc1~1478^2~1
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=80954da5b612fda22ab7843653e881f07c5bdf76;p=dealii.git

Fix IndexSet::is_ascending_and_one_to_one for empty objects
---

diff --git a/source/base/index_set.cc b/source/base/index_set.cc
index 9b833fcb7c..8815d6919b 100644
--- a/source/base/index_set.cc
+++ b/source/base/index_set.cc
@@ -672,6 +672,9 @@ IndexSet::is_ascending_and_one_to_one(const MPI_Comm &communicator) const
   if (n_global_elements != size())
     return false;
 
+  if (n_global_elements == 0)
+    return true;
+
 #ifdef DEAL_II_WITH_MPI
   // Non-contiguous IndexSets can't be linear.
   const bool all_contiguous =