step-42: fix deadlock with many CPUs

git-svn-id: https://svn.dealii.org/trunk@25588 0785d39b-7218-0410-832d-ea1e28bc413d

diff --git a/deal.II/examples/step-42/step-42.cc b/deal.II/examples/step-42/step-42.cc
index 5683e4af2abbfad0d941a1bbaf6063fdf6137daf..1f434510dd6d86bb5659dc7c7e9454348c846ebb 100644 (file)
--- a/deal.II/examples/step-42/step-42.cc
+++ b/deal.II/examples/step-42/step-42.cc
@@ -794,7 +794,7 @@ void Step4<dim>::assemble_nl_system (TrilinosWrappers::MPI::Vector &u)
       };
 
   system_matrix_newton.compress ();
-  system_rhs_newton.compress ();
+  system_rhs_newton.compress (Add);
 }
 
 template <int dim>