From: Martin Kronbichler <kronbichler@lnm.mw.tum.de>
Date: Tue, 22 Mar 2011 10:15:14 +0000 (+0000)
Subject: Trilinos expects a valid pointer for constant modes also when there is no data owned... 
X-Git-Tag: v8.0.0~4214
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=24cad6023974e035da0b6c35f924de25d1455f02;p=dealii.git

Trilinos expects a valid pointer for constant modes also when there is no data owned locally.

git-svn-id: https://svn.dealii.org/trunk@23488 0785d39b-7218-0410-832d-ea1e28bc413d
---

diff --git a/deal.II/source/lac/trilinos_precondition.cc b/deal.II/source/lac/trilinos_precondition.cc
index fdf798dac6..c8e4d938ca 100644
--- a/deal.II/source/lac/trilinos_precondition.cc
+++ b/deal.II/source/lac/trilinos_precondition.cc
@@ -578,6 +578,7 @@ namespace TrilinosWrappers
       additional_data.constant_modes.size();
     Epetra_MultiVector distributed_constant_modes (domain_map,
 						   constant_modes_dimension);
+    std::vector<double> dummy (constant_modes_dimension);
 
     if (constant_modes_dimension > 1)
       {
@@ -609,8 +610,16 @@ namespace TrilinosWrappers
 	parameter_list.set("null space: type", "pre-computed");
 	parameter_list.set("null space: dimension",
 			   distributed_constant_modes.NumVectors());
-	parameter_list.set("null space: vectors",
-			   distributed_constant_modes.Values());
+	if (my_size > 0)
+	  parameter_list.set("null space: vectors",
+			     distributed_constant_modes.Values());
+				// We need to set a valid pointer to data even
+				// if there is no data on the current
+				// processor. Therefore, pass a dummy in that
+				// case
+	else
+	  parameter_list.set("null space: vectors",
+			     &dummy[0]);
       }
 
     initialize (matrix, parameter_list);