From 82b8ddc0420935ef2e4dae704a93f94e2e9d3dc2 Mon Sep 17 00:00:00 2001
From: wmayer <wmayer@users.sourceforge.net>
Date: Mon, 13 Jun 2022 14:21:18 +0200
Subject: [PATCH] Fem: use WeakPtrT classes instead of raw pointers to avoid
 possible dangling pointers and to avoid undefined behaviour if a wrong
 static_cast is performed

---
 src/Mod/Fem/Gui/TaskPostBoxes.cpp | 11 ++++++-----
 src/Mod/Fem/Gui/TaskPostBoxes.h   | 29 ++++++++++++++++++++---------
 2 files changed, 26 insertions(+), 14 deletions(-)

diff --git a/src/Mod/Fem/Gui/TaskPostBoxes.cpp b/src/Mod/Fem/Gui/TaskPostBoxes.cpp
index bc77191f97..fc2e2fcbe0 100644
--- a/src/Mod/Fem/Gui/TaskPostBoxes.cpp
+++ b/src/Mod/Fem/Gui/TaskPostBoxes.cpp
@@ -212,7 +212,8 @@ ViewProviderDataMarker::~ViewProviderDataMarker()
 // ***************************************************************************
 
 TaskDlgPost::TaskDlgPost(Gui::ViewProviderDocumentObject* view)
-    : TaskDialog(), m_view(view)
+    : TaskDialog()
+    , m_view(view)
 {
     assert(view);
 }
@@ -289,10 +290,10 @@ void TaskDlgPost::modifyStandardButtons(QDialogButtonBox* box) {
 // ***************************************************************************
 // some task box methods
 TaskPostBox::TaskPostBox(Gui::ViewProviderDocumentObject* view, const QPixmap& icon, const QString& title, QWidget* parent)
-    : TaskBox(icon, title, true, parent) {
-
-    m_view = view;
-    m_object = view->getObject();
+    : TaskBox(icon, title, true, parent)
+    , m_object(view->getObject())
+    , m_view(view)
+{
 }
 
 TaskPostBox::~TaskPostBox() {
diff --git a/src/Mod/Fem/Gui/TaskPostBoxes.h b/src/Mod/Fem/Gui/TaskPostBoxes.h
index 9c81376d2a..34e2e948c4 100644
--- a/src/Mod/Fem/Gui/TaskPostBoxes.h
+++ b/src/Mod/Fem/Gui/TaskPostBoxes.h
@@ -23,6 +23,8 @@
 #ifndef GUI_TASKVIEW_TaskPostDisplay_H
 #define GUI_TASKVIEW_TaskPostDisplay_H
 
+#include <App/DocumentObserver.h>
+#include <Gui/DocumentObserver.h>
 #include <Gui/ViewProviderDocumentObject.h>
 #include <Gui/TaskView/TaskDialog.h>
 #include <Gui/TaskView/TaskView.h>
@@ -143,12 +145,20 @@ public:
     virtual bool isGuiTaskOnly() {return false;} //return true if only gui properties are manipulated
 
 protected:
-    App::DocumentObject*                getObject() {return m_object;}
+    App::DocumentObject* getObject() const {
+        return *m_object;
+    }
     template<typename T>
-    T* getTypedObject() {return static_cast<T*>(m_object);}
-    Gui::ViewProviderDocumentObject*    getView() {return m_view;}
+    T* getTypedObject() const {
+        return m_object.get<T>();
+    }
+    Gui::ViewProviderDocumentObject* getView() const {
+        return *m_view;
+    }
     template<typename T>
-    T* getTypedView() {return static_cast<T*>(m_view);}
+    T* getTypedView() const {
+        return m_view.get<T>();
+    }
 
     bool autoApply();
     void recompute();
@@ -156,8 +166,8 @@ protected:
     static void updateEnumerationList(App::PropertyEnumeration&, QComboBox* box);
 
 private:
-    App::DocumentObject*              m_object;
-    Gui::ViewProviderDocumentObject*  m_view;
+    App::DocumentObjectWeakPtrT m_object;
+    Gui::ViewProviderWeakPtrT   m_view;
 };
 
 
@@ -171,8 +181,9 @@ public:
     ~TaskDlgPost();
 
     void appendBox(TaskPostBox* box);
-    Gui::ViewProviderDocumentObject* getView() const
-    { return m_view; }
+    Gui::ViewProviderDocumentObject* getView() const {
+        return *m_view;
+    }
 
 public:
     /// is called the TaskView when the dialog is opened
@@ -192,7 +203,7 @@ public:
     virtual QDialogButtonBox::StandardButtons getStandardButtons(void) const;
 
 protected:
-    Gui::ViewProviderDocumentObject*  m_view;
+    Gui::ViewProviderWeakPtrT   m_view;
     std::vector<TaskPostBox*>   m_boxes;
 };