Fix T54136: Crash when deleting an object that is in an instanced group

We were not cleaning up groups after deleting objects, leaving groups with
Bases that had no object.

It includes a unittest.

Reviewers: mont29

2 files changed, 73 insertions, 0 deletions

diff --git a/tests/python/view_layer/CMakeLists.txt b/tests/python/view_layer/CMakeLists.txt
index cc5a3ba54b1..77a56fb47f9 100644
--- a/tests/python/view_layer/CMakeLists.txt
+++ b/tests/python/view_layer/CMakeLists.txt
@@ -94,6 +94,7 @@ VIEW_LAYER_TEST(group_a)
 VIEW_LAYER_TEST(group_b)
 VIEW_LAYER_TEST(group_c)
 VIEW_LAYER_TEST(group_d)
+VIEW_LAYER_TEST(group_e)
 VIEW_LAYER_TEST(object_add_cylinder)
 VIEW_LAYER_TEST(object_add_empty)
 VIEW_LAYER_TEST(object_add_torus)
diff --git a/tests/python/view_layer/test_group_e.py b/tests/python/view_layer/test_group_e.py
new file mode 100644
index 00000000000..566c043572e
--- /dev/null
+++ b/tests/python/view_layer/test_group_e.py
@@ -0,0 +1,72 @@
+# ############################################################
+# Importing - Same For All Render Layer Tests
+# ############################################################
+
+import unittest
+import os
+import sys
+
+from view_layer_common import *
+
+
+# ############################################################
+# Testing
+# ############################################################
+
+class UnitTesting(ViewLayerTesting):
+    def test_group_delete_object(self):
+        """
+        See if we can safely remove instanced objects
+        """
+        import bpy
+        scene = bpy.context.scene
+        view_layer = bpy.context.view_layer
+        ob = bpy.context.object
+
+        # clean up the scene a bit
+        for o in (o for o in view_layer.objects if o != ob):
+            view_layer.collections[0].collection.objects.unlink(o)
+
+        for v in (v for v in scene.view_layers if v != view_layer):
+            scene.view_layers.remove(v)
+
+        # update depsgraph
+        scene.update()
+
+        # create group
+        group = bpy.data.groups.new("Switch")
+        group.objects.link(ob)
+
+        # update depsgraph
+        scene.update()
+
+        # instance the group
+        empty = bpy.data.objects.new("Empty", None)
+        bpy.context.scene_collection.objects.link(empty)
+        layer_collection = bpy.context.layer_collection
+        empty.dupli_type = 'GROUP'
+        empty.dupli_group = group
+
+        # prepare to delete the original object
+        # we could just pass an overridden context
+        # but let's do it the old fashion way
+        view_layer.objects.active = ob
+        ob.select_set('SELECT')
+        self.assertTrue(ob.select_get())
+        empty.select_set('DESELECT')
+        self.assertFalse(empty.select_get())
+
+        # update depsgraph
+        scene.update()
+
+        # delete the original object
+        bpy.ops.object.delete()
+
+
+# ############################################################
+# Main - Same For All Render Layer Tests
+# ############################################################
+
+if __name__ == '__main__':
+    UnitTesting._extra_arguments = setup_extra_arguments(__file__)
+    unittest.main()