From: Wolfgang Bangerth <bangerth@math.tamu.edu>
Date: Tue, 18 May 2004 21:47:40 +0000 (+0000)
Subject: Fix a problem where we were running past the end of an array and still
X-Git-Tag: v8.0.0~15169
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=051e6b3de2f863835404d8fb81ba91de23d497de;p=dealii.git

Fix a problem where we were running past the end of an array and still
dereferenced the iterator.


git-svn-id: https://svn.dealii.org/trunk@9260 0785d39b-7218-0410-832d-ea1e28bc413d
---

diff --git a/deal.II/deal.II/source/dofs/dof_constraints.cc b/deal.II/deal.II/source/dofs/dof_constraints.cc
index 26370850e9..ec70e24e9e 100644
--- a/deal.II/deal.II/source/dofs/dof_constraints.cc
+++ b/deal.II/deal.II/source/dofs/dof_constraints.cc
@@ -1176,7 +1176,17 @@ bool ConstraintMatrix::is_identity_constrained (const unsigned int index) const
 	p = std::lower_bound (lines.begin (),
 			      lines.end (),
 			      index_comparison);
-      return ((p->line == index) &&
+				       // return if an entry for this
+				       // line was found and if it has
+				       // only one entry equal to 1.0
+				       //
+				       // note that lower_bound only
+				       // returns a valid iterator if
+				       // 'index' is less than the
+				       // largest line index in out
+				       // constraints list
+      return ((p != lines.end()) &&
+	      (p->line == index) &&
 	      (p->entries.size() == 1) &&
 	      (p->entries[0].second == 1.0));
     }
@@ -1189,7 +1199,7 @@ bool ConstraintMatrix::is_identity_constrained (const unsigned int index) const
 		  (i->entries[0].second == 1.0));
 
       return false;
-    };
+    }
 }