From 90d546d1e7d99a3f2a6594a23bfe73ca2a9d8d51 Mon Sep 17 00:00:00 2001
From: wmayer <wmayer@users.sourceforge.net>
Date: Sat, 19 Mar 2022 15:37:31 +0100
Subject: [PATCH] Fem: replace raw pointer with WeakPtrT to check if the object
 has been deleted, fix crash in destructor of TaskFemConstraintOnBoundary

---
 src/Mod/Fem/Gui/TaskFemConstraint.h             | 5 +++--
 src/Mod/Fem/Gui/TaskFemConstraintOnBoundary.cpp | 3 ++-
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/Mod/Fem/Gui/TaskFemConstraint.h b/src/Mod/Fem/Gui/TaskFemConstraint.h
index 2dab3c55d0..2474347fbe 100644
--- a/src/Mod/Fem/Gui/TaskFemConstraint.h
+++ b/src/Mod/Fem/Gui/TaskFemConstraint.h
@@ -25,9 +25,10 @@
 #ifndef GUI_TASKVIEW_TaskFemConstraint_H
 #define GUI_TASKVIEW_TaskFemConstraint_H
 
-#include <Gui/TaskView/TaskView.h>
+#include <Gui/DocumentObserver.h>
 #include <Gui/Selection.h>
 #include <Gui/TaskView/TaskDialog.h>
+#include <Gui/TaskView/TaskView.h>
 
 #include "ViewProviderFemConstraint.h"
 
@@ -69,7 +70,7 @@ protected:
 protected:
     QWidget* proxy;
     QAction* deleteAction;
-    ViewProviderFemConstraint *ConstraintView;
+    Gui::WeakPtrT<ViewProviderFemConstraint> ConstraintView;
     enum {seldir, selref, selloc, selnone} selectionMode;
 
 private:
diff --git a/src/Mod/Fem/Gui/TaskFemConstraintOnBoundary.cpp b/src/Mod/Fem/Gui/TaskFemConstraintOnBoundary.cpp
index b85f91db73..a57fca6e4b 100644
--- a/src/Mod/Fem/Gui/TaskFemConstraintOnBoundary.cpp
+++ b/src/Mod/Fem/Gui/TaskFemConstraintOnBoundary.cpp
@@ -39,7 +39,8 @@ TaskFemConstraintOnBoundary::TaskFemConstraintOnBoundary(ViewProviderFemConstrai
 
 TaskFemConstraintOnBoundary::~TaskFemConstraintOnBoundary()
 {
-    ConstraintView->highlightReferences(false);
+    if (!ConstraintView.expired())
+        ConstraintView->highlightReferences(false);
 }
 
 void TaskFemConstraintOnBoundary::_addToSelection(bool checked)