From d87d230bb4bcbe091fe35bb047d54f7d9fcaabb8 Mon Sep 17 00:00:00 2001
From: Nyall Dawson <nyall.dawson@gmail.com>
Date: Wed, 14 Oct 2020 13:31:59 +1000
Subject: [PATCH] Fix crash in undo dock when clearing project/closing QGIS

Fixes #38157
---
 src/app/qgsundowidget.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/app/qgsundowidget.h b/src/app/qgsundowidget.h
index aa12c8515124..8c02251c55ca 100644
--- a/src/app/qgsundowidget.h
+++ b/src/app/qgsundowidget.h
@@ -25,6 +25,7 @@
 #include <QWidget>
 #include <QUndoView>
 #include <QUndoStack>
+#include <QPointer>
 
 #include "qgspanelwidget.h"
 #include "qgis_app.h"
@@ -93,7 +94,7 @@ class APP_EXPORT QgsUndoWidget : public QgsPanelWidget
 
   private:
     QUndoView *mUndoView = nullptr;
-    QUndoStack *mUndoStack = nullptr;
+    QPointer< QUndoStack > mUndoStack;
     QgsMapCanvas *mMapCanvas = nullptr;
 
     int mPreviousIndex = 0;