p:f:Tria: Fix bug when a process does not own cells on a level

diff --git a/source/distributed/fully_distributed_tria.cc b/source/distributed/fully_distributed_tria.cc
index 802d8b599690c2c374f3e6a9b59fe0114b60fac7..ca160614c8dcf7b78a1a5ce26a3efe47abf27043 100644 (file)
--- a/source/distributed/fully_distributed_tria.cc
+++ b/source/distributed/fully_distributed_tria.cc
@@ -184,7 +184,9 @@ namespace parallel
             }
 
           // 4b) set actual (level_)subdomain_ids
-          for (unsigned int level = 0; level < cell_infos.size(); ++level)
+          for (unsigned int level = 0;
+               level < cell_infos.size() && !cell_infos[level].empty();
+               ++level)
             {
               auto cell      = this->begin(level);
               auto cell_info = cell_infos[level].begin();

diff --git a/source/grid/tria.cc b/source/grid/tria.cc
index 2f737a0bb4dce4af1b36c1fd5acd2913d70b6a22..d7900e35c1f0bb2a72654862c20ef7273ae68a92 100644 (file)
--- a/source/grid/tria.cc
+++ b/source/grid/tria.cc
@@ -10660,8 +10660,12 @@ Triangulation<dim, spacedim>::create_triangulation(
           return a_id < b_id;
       });
 
-  // 2) create all levels via a sequence of refinements
-  for (unsigned int level = 0; level < cell_infos.size(); ++level)
+  // 2) create all levels via a sequence of refinements. note that
+  //    we must make sure that we actually have cells on this level,
+  //    which is not clear in a parallel context for some processes
+  for (unsigned int level = 0;
+       level < cell_infos.size() && !cell_infos[level].empty();
+       ++level)
     {
       // a) set manifold ids here (because new vertices have to be
       //    positioned correctly during each refinement step)
@@ -10714,7 +10718,9 @@ Triangulation<dim, spacedim>::create_triangulation(
     }
 
   // 3) set boundary ids
-  for (unsigned int level = 0; level < cell_infos.size(); ++level)
+  for (unsigned int level = 0;
+       level < cell_infos.size() && !cell_infos[level].empty();
+       ++level)
     {
       auto cell      = this->begin(level);
       auto cell_info = cell_infos[level].begin();