Fix unnecessarily added undo steps when deleting only scene

Steps to reproduce were: startup.blend, move any object, delete active scene (nothing happens), undo (nothing happens), second undo is needed to revert object transformation

2 files changed, 11 insertions, 4 deletions

diff --git a/source/blender/editors/screen/screen_edit.c b/source/blender/editors/screen/screen_edit.c
index ae0d2619645..b714eb00169 100644
--- a/source/blender/editors/screen/screen_edit.c
+++ b/source/blender/editors/screen/screen_edit.c
@@ -1707,8 +1707,11 @@ void ED_screen_set_scene(bContext *C, bScreen *screen, Scene *scene)
 	
 }
 
-/* only call outside of area/region loops */
-void ED_screen_delete_scene(bContext *C, Scene *scene)
+/**
+ * \note Only call outside of area/region loops
+ * \return true if successful
+ */
+bool ED_screen_delete_scene(bContext *C, Scene *scene)
 {
 	Main *bmain = CTX_data_main(C);
 	Scene *newscene;
@@ -1718,11 +1721,13 @@ void ED_screen_delete_scene(bContext *C, Scene *scene)
 	else if (scene->id.next)
 		newscene = scene->id.next;
 	else
-		return;
+		return false;
 
 	ED_screen_set_scene(C, CTX_wm_screen(C), newscene);
 
 	BKE_scene_unlink(bmain, scene, newscene);
+
+	return true;
 }
 
 ScrArea *ED_screen_full_newspace(bContext *C, ScrArea *sa, int type)
diff --git a/source/blender/editors/screen/screen_ops.c b/source/blender/editors/screen/screen_ops.c
index 1d31cc04e38..1309fb103e9 100644
--- a/source/blender/editors/screen/screen_ops.c
+++ b/source/blender/editors/screen/screen_ops.c
@@ -3986,7 +3986,9 @@ static int scene_delete_exec(bContext *C, wmOperator *UNUSED(op))
 {
 	Scene *scene = CTX_data_scene(C);
 
-	ED_screen_delete_scene(C, scene);
+	if (ED_screen_delete_scene(C, scene) == false) {
+		return OPERATOR_CANCELLED;
+	}
 
 	if (G.debug & G_DEBUG)
 		printf("scene delete %p\n", scene);