Fix SolutionTransfer to properly compress() vectors.

diff --git a/source/numerics/solution_transfer.cc b/source/numerics/solution_transfer.cc
index 90d5885ac897b1485773589101e86cdaadb7ce57..74bffa4ec32da60a8ed3c07ea57ab88a3f0128cf 100644 (file)
--- a/source/numerics/solution_transfer.cc
+++ b/source/numerics/solution_transfer.cc
@@ -583,6 +583,11 @@ SolutionTransfer<dim, VectorType, spacedim>::interpolate(
             Assert(false, ExcInternalError());
         }
     }
+
+  // We have written into the output vectors. If this was a PETSc vector, for
+  // example, then we need to compress these to make future operations safe:
+  for (auto &vec : all_out)
+    vec.compress(VectorOperation::insert);
 }