Fix #7587. See #7550. Bug where you couldn't load or edit arrayed voids.

Reuse tool.Geometry.duplicate_ifc_objects because that's where all
duplication logic should stay instead of half reimplementing it every
time which introduces subtle bugs.

src/bonsai/bonsai/tool/blender.py

@@ -1223,7 +1223,8 @@ class Blender(bonsai.core.tool.Blender):
 
             @classmethod
             def constrain_children_to_parent(cls, parent_element: ifcopenshell.entity_instance) -> None:
-                parent_obj = tool.Ifc.get_object(parent_element)
+                if not (parent_obj := tool.Ifc.get_object(parent_element)):
+                    return  # Filtered out, arrayed void, etc
                 assert isinstance(parent_obj, bpy.types.Object)
                 children = cls.get_all_children_objects(parent_element)
                 for child in children:

src/bonsai/bonsai/tool/geometry.py

@@ -2106,6 +2106,14 @@ class Geometry(bonsai.core.tool.Geometry):
         active_object: Optional[bpy.types.Object] = None,
         linked: bool = False,
     ) -> tuple[dict[ifcopenshell.entity_instance, list[ifcopenshell.entity_instance]], Union[bpy.types.Object, None]]:
+        """Duplicate IFC objects
+
+        Duplication is surprisingly complicated because you might only select
+        part of a group of related items.
+
+        TODO: write some tests and figure out how to make this function
+        actually understandable.
+        """
         # Handle arrays
         objects_to_duplicate = set(objects_to_duplicate)
         arrays_to_duplicate, array_children = cls.process_arrays_for_duplication(objects_to_duplicate)

src/bonsai/bonsai/tool/model.py

@@ -1063,8 +1063,7 @@ class Model(bonsai.core.tool.Model):
                 removed_children = set(array["children"])
                 for removed_child in removed_children:
                     element = tool.Ifc.get().by_guid(removed_child)
-                    obj = tool.Ifc.get_object(element)
-                    if obj:
+                    if obj := tool.Ifc.get_object(element):
                         tool.Geometry.delete_ifc_object(obj)
                 array["children"].clear()
 
@@ -1087,19 +1086,18 @@ class Model(bonsai.core.tool.Model):
                 offset = base_offset * i
 
                 for obj in obj_stack:
-                    # get currently proccesed array element and it's object
-                    if child_i >= total_existing_children:
-                        child_obj = tool.Spatial.duplicate_object_and_data(obj)
-                        child_element = tool.Spatial.run_root_copy_class(obj=child_obj)
-                    else:
+                    try:
                         global_id = array["children"][child_i]
-                        try:
-                            child_element = tool.Ifc.get().by_guid(global_id)
-                            child_obj = tool.Ifc.get_object(child_element)
-                            assert child_obj
-                        except:
-                            child_obj = tool.Spatial.duplicate_object_and_data(obj)
-                            child_element = tool.Spatial.run_root_copy_class(obj=child_obj)
+                        child_element = tool.Ifc.get().by_guid(global_id)
+                        child_obj = tool.Ifc.get_object(child_element)
+                        assert child_obj
+                    except:
+                        old_to_new, _ = tool.Geometry.duplicate_ifc_objects([obj])
+                        # TODO Is this correct to assume one child? I really
+                        # don't understand the linked aggregates and array
+                        # behaviour.
+                        child_element = list(old_to_new.values())[0][0]
+                        child_obj = tool.Ifc.get_object(child_element)
 
                     # add child pset
                     child_pset = tool.Pset.get_element_pset(child_element, "BBIM_Array")