From 6ba0e3d1b4c9e9ea2b1dbbba43cb4032ff8d665f Mon Sep 17 00:00:00 2001
From: Martin Kronbichler <kronbichler@lnm.mw.tum.de>
Date: Thu, 18 Jul 2019 14:29:22 +0200
Subject: [PATCH] Be more conservative in clearing the cache of MappingQCache

---
 source/fe/mapping_q_cache.cc | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/source/fe/mapping_q_cache.cc b/source/fe/mapping_q_cache.cc
index 32d5bb7491..9c7cae10e6 100644
--- a/source/fe/mapping_q_cache.cc
+++ b/source/fe/mapping_q_cache.cc
@@ -42,8 +42,12 @@ MappingQCache<dim, spacedim>::MappingQCache(
 template <int dim, int spacedim>
 MappingQCache<dim, spacedim>::~MappingQCache()
 {
-  if (clear_signal.connected())
-    clear_signal.disconnect();
+  // When this object goes out of scope, we want the cache to get cleared and
+  // free its memory before the signal is disconnected in order to not work on
+  // invalid memory that has been left back by freeing an object of this
+  // class.
+  support_point_cache.reset();
+  clear_signal.disconnect();
 }
 
 
-- 
2.39.5