Add comment why to call update_number_cache

diff --git a/source/distributed/tria.cc b/source/distributed/tria.cc
index d9fc1b5e1ba15a5cf5dbb6cda6128a5f6c637e70..532ef242629ea5490d87160ee37a23f07421dabe 100644 (file)
--- a/source/distributed/tria.cc
+++ b/source/distributed/tria.cc
@@ -3522,6 +3522,8 @@ namespace parallel
 
       //finally call the base class for storing the periodicity information
       dealii::Triangulation<dim, spacedim>::add_periodicity(periodicity_vector);
+
+      // The range of ghost_owners might have changed so update that information
       this->update_number_cache();
 #else
       Assert(false, ExcMessage ("Need p4est version >= 0.3.4.1!"));