From 2feb8d32a9eb4af95b2de6a90825620e3d8ed4e0 Mon Sep 17 00:00:00 2001
From: Peter Munch <peterrmuench@gmail.com>
Date: Tue, 11 May 2021 09:40:06 +0200
Subject: [PATCH] MappingQCache: assert that level information was set up

---
 include/deal.II/fe/mapping_q_cache.h |  6 ++++++
 source/fe/mapping_q_cache.cc         | 14 ++++++++++++++
 2 files changed, 20 insertions(+)

diff --git a/include/deal.II/fe/mapping_q_cache.h b/include/deal.II/fe/mapping_q_cache.h
index 3854993ec8..893141d35f 100644
--- a/include/deal.II/fe/mapping_q_cache.h
+++ b/include/deal.II/fe/mapping_q_cache.h
@@ -232,6 +232,12 @@ private:
    * this class goes out of scope.
    */
   boost::signals2::connection clear_signal;
+
+  /**
+   * Specifies if support_point_cache has been set up for the cells on the
+   * levels.
+   */
+  bool uses_level_info;
 };
 
 /*@}*/
diff --git a/source/fe/mapping_q_cache.cc b/source/fe/mapping_q_cache.cc
index 220a781a15..563dbc0289 100644
--- a/source/fe/mapping_q_cache.cc
+++ b/source/fe/mapping_q_cache.cc
@@ -40,6 +40,7 @@ template <int dim, int spacedim>
 MappingQCache<dim, spacedim>::MappingQCache(
   const unsigned int polynomial_degree)
   : MappingQGeneric<dim, spacedim>(polynomial_degree)
+  , uses_level_info(false)
 {}
 
 
@@ -49,6 +50,7 @@ MappingQCache<dim, spacedim>::MappingQCache(
   const MappingQCache<dim, spacedim> &mapping)
   : MappingQGeneric<dim, spacedim>(mapping)
   , support_point_cache(mapping.support_point_cache)
+  , uses_level_info(mapping.uses_level_info)
 {}
 
 
@@ -180,6 +182,8 @@ MappingQCache<dim, spacedim>::initialize(
     /* copy_data */ nullptr,
     2 * MultithreadInfo::n_threads(),
     /* chunk_size = */ 1);
+
+  uses_level_info = true;
 }
 
 
@@ -245,6 +249,8 @@ MappingQCache<dim, spacedim>::initialize(
 
       return points;
     });
+
+  uses_level_info = true;
 }
 
 
@@ -268,6 +274,8 @@ MappingQCache<dim, spacedim>::initialize(
                      return new_point;
                    },
                    function_describes_relative_displacement);
+
+  uses_level_info = true;
 }
 
 
@@ -481,6 +489,8 @@ MappingQCache<dim, spacedim>::initialize(
 
       return result;
     });
+
+  uses_level_info = false;
 }
 
 
@@ -694,6 +704,8 @@ MappingQCache<dim, spacedim>::initialize(
 
       return result;
     });
+
+  uses_level_info = true;
 }
 
 
@@ -720,6 +732,8 @@ MappingQCache<dim, spacedim>::compute_mapping_support_points(
          ExcMessage("Must call MappingQCache::initialize() before "
                     "using it or after mesh has changed!"));
 
+  Assert(uses_level_info || cell->is_active(), ExcInternalError());
+
   AssertIndexRange(cell->level(), support_point_cache->size());
   AssertIndexRange(cell->index(), (*support_point_cache)[cell->level()].size());
   return (*support_point_cache)[cell->level()][cell->index()];
-- 
2.39.5