From: Matthias Maier <tamiko@43-1.org>
Date: Mon, 22 Apr 2019 19:32:19 +0000 (-0500)
Subject: improve error message
X-Git-Tag: v9.1.0-rc1~190^2
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=refs%2Fpull%2F7926%2Fhead;p=dealii.git

improve error message
---

diff --git a/source/lac/dynamic_sparsity_pattern.cc b/source/lac/dynamic_sparsity_pattern.cc
index b96163570f..5631edc661 100644
--- a/source/lac/dynamic_sparsity_pattern.cc
+++ b/source/lac/dynamic_sparsity_pattern.cc
@@ -358,7 +358,11 @@ DynamicSparsityPattern::exists(const size_type i, const size_type j) const
 {
   Assert(i < rows, ExcIndexRange(i, 0, rows));
   Assert(j < cols, ExcIndexRange(j, 0, cols));
-  Assert(rowset.size() == 0 || rowset.is_element(i), ExcInternalError());
+  Assert(
+    rowset.size() == 0 || rowset.is_element(i),
+    ExcMessage(
+      "The row IndexSet does not contain the index i. This sparsity pattern "
+      "object cannot know whether the entry (i, j) exists or not."));
 
   // Avoid a segmentation fault in below code if the row index happens to
   // not be present in the IndexSet rowset: