From e33fc007c78b29075d0fae5973e68ac1ddb47f65 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Cl=C3=A9ment=20Fauconnier?= <fc86@outlook.fr>
Date: Fri, 17 Dec 2021 10:24:12 +0100
Subject: [PATCH] prevent a crash when clearBackground then undo then redo then
 clearBackground

---
 src/domain/UBGraphicsItemUndoCommand.cpp | 6 +++++-
 src/domain/UBGraphicsScene.cpp           | 1 +
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/domain/UBGraphicsItemUndoCommand.cpp b/src/domain/UBGraphicsItemUndoCommand.cpp
index 4787aed5..8ad68b22 100644
--- a/src/domain/UBGraphicsItemUndoCommand.cpp
+++ b/src/domain/UBGraphicsItemUndoCommand.cpp
@@ -246,7 +246,11 @@ void UBGraphicsItemUndoCommand::redo()
 
                 polygonItem->strokesGroup()->removeFromGroup(polygonItem);
             }
-            mScene->removeItem(item);
+
+            if (itemLayerType::BackgroundItem == item->data(UBGraphicsItemData::itemLayerType))
+                mScene->setAsBackgroundObject(nullptr);
+            else
+                mScene->removeItem(item);
 
             if (bApplyTransform)
                 item->setTransform(t);
diff --git a/src/domain/UBGraphicsScene.cpp b/src/domain/UBGraphicsScene.cpp
index 0336a63c..533b97c1 100644
--- a/src/domain/UBGraphicsScene.cpp
+++ b/src/domain/UBGraphicsScene.cpp
@@ -1476,6 +1476,7 @@ void UBGraphicsScene::clearContent(clearCase pCase)
         if(mBackgroundObject){
             removeItem(mBackgroundObject);
             removedItems << mBackgroundObject;
+            mBackgroundObject = nullptr;
         }
         break;