From: Peter Munch <peterrmuench@gmail.com>
Date: Sun, 6 Feb 2022 06:01:38 +0000 (+0100)
Subject: Fix assert message for empty vector
X-Git-Tag: v9.4.0-rc1~524^2
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=refs%2Fpull%2F13340%2Fhead;p=dealii.git

Fix assert message for empty vector
---

diff --git a/include/deal.II/lac/la_parallel_vector.h b/include/deal.II/lac/la_parallel_vector.h
index 15988bdc09..a8be748565 100644
--- a/include/deal.II/lac/la_parallel_vector.h
+++ b/include/deal.II/lac/la_parallel_vector.h
@@ -1640,7 +1640,9 @@ namespace LinearAlgebra
           partitioner->ghost_indices().is_element(global_index),
         ExcAccessToNonLocalElement(global_index,
                                    partitioner->local_range().first,
-                                   partitioner->local_range().second - 1,
+                                   partitioner->local_range().second == 0 ?
+                                     0 :
+                                     (partitioner->local_range().second - 1),
                                    partitioner->ghost_indices().n_elements()));
       // do not allow reading a vector which is not in ghost mode
       Assert(partitioner->in_local_range(global_index) ||
@@ -1664,7 +1666,9 @@ namespace LinearAlgebra
           partitioner->ghost_indices().is_element(global_index),
         ExcAccessToNonLocalElement(global_index,
                                    partitioner->local_range().first,
-                                   partitioner->local_range().second - 1,
+                                   partitioner->local_range().second == 0 ?
+                                     0 :
+                                     (partitioner->local_range().second - 1),
                                    partitioner->ghost_indices().n_elements()));
       // we would like to prevent reading ghosts from a vector that does not
       // have them imported, but this is not possible because we might be in a