From ee0a0817f9761643f92bd0bb40860b039301a04e Mon Sep 17 00:00:00 2001
From: wmayer <wmayer@users.sourceforge.net>
Date: Fri, 21 Oct 2022 10:23:53 +0200
Subject: [PATCH] Sketcher: fix possible crash when closing the sketcher For
 more details see the forum thread:
 https://forum.freecadweb.org/viewtopic.php?f=13&t=72774

---
 src/Mod/Sketcher/Gui/ViewProviderSketch.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/Mod/Sketcher/Gui/ViewProviderSketch.cpp b/src/Mod/Sketcher/Gui/ViewProviderSketch.cpp
index 43f7e2734c..bf9da57b16 100644
--- a/src/Mod/Sketcher/Gui/ViewProviderSketch.cpp
+++ b/src/Mod/Sketcher/Gui/ViewProviderSketch.cpp
@@ -3166,6 +3166,7 @@ void ViewProviderSketch::unsetEditViewer(Gui::View3DInventorViewer* viewer)
     auto dataPtr = static_cast<VPRender*>(cameraSensor.getData());
     dataPtr->attached = false;
     delete dataPtr;
+    cameraSensor.setData(nullptr);
     cameraSensor.detach();
 
     viewer->removeGraphicsItem(rubberband.get());
@@ -3177,7 +3178,7 @@ void ViewProviderSketch::unsetEditViewer(Gui::View3DInventorViewer* viewer)
 void ViewProviderSketch::camSensCB(void *data, SoSensor *)
 {
     VPRender *proxyVPrdr = static_cast<VPRender*>(data);
-    if (!proxyVPrdr->attached)
+    if (!proxyVPrdr || !proxyVPrdr->attached)
         return;
 
     auto vp = proxyVPrdr->vp;