From: Matthias Maier <tamiko@43-1.org>
Date: Mon, 22 Apr 2019 19:18:45 +0000 (-0500)
Subject: avoid a segmentation fault
X-Git-Tag: v9.1.0-rc1~190^2~1
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=aae1a0580b896086c557856b9eafa6d5534d5351;p=dealii.git

avoid a segmentation fault
---

diff --git a/source/lac/dynamic_sparsity_pattern.cc b/source/lac/dynamic_sparsity_pattern.cc
index cb93d1a37d..b96163570f 100644
--- a/source/lac/dynamic_sparsity_pattern.cc
+++ b/source/lac/dynamic_sparsity_pattern.cc
@@ -360,6 +360,11 @@ DynamicSparsityPattern::exists(const size_type i, const size_type j) const
   Assert(j < cols, ExcIndexRange(j, 0, cols));
   Assert(rowset.size() == 0 || rowset.is_element(i), ExcInternalError());
 
+  // Avoid a segmentation fault in below code if the row index happens to
+  // not be present in the IndexSet rowset:
+  if (!(rowset.size() == 0 || rowset.is_element(i)))
+    return false;
+
   if (!have_entries)
     return false;