get_inverse_attributes - added more correct recursive unpacking for aggregates and selections

Not affected the result schemas though

src/ifcopenshell-python/ifcopenshell/util/doc.py

@@ -160,20 +160,30 @@ def get_type_doc(version, ifc_type):
         return db["types"].get(ifc_type)
 
 
+# TODO: there are still some discrepancies between this method
+# and the specs website because of the asymmetry
+# More: https://github.com/buildingSMART/IFC4.3.x-development/issues/582
 def get_inverse_attributes(el):
     inverse_attrs = []
     for a in el.all_inverse_attributes():
         attribute_type = a.attribute_reference().type_of_attribute()
-        if isinstance(attribute_type, ifcopenshell.ifcopenshell_wrapper.aggregation_type):
+        # unpacking aggregation types
+        while isinstance(attribute_type, ifcopenshell.ifcopenshell_wrapper.aggregation_type):
             attribute_type = attribute_type.type_of_element()
         attribute_type = attribute_type.declared_type()
 
-        if not isinstance(attribute_type, ifcopenshell.ifcopenshell_wrapper.entity):
-            attr_types = [t.name() for t in attribute_type.select_list()]
-        else:
-            attr_types = [attribute_type.name()]
+        # recursively looking for entities inside the selections
+        types_to_process = [attribute_type]
+        entity_attr_types = []
+        while types_to_process:
+            for attr_type in types_to_process.copy():
+                if isinstance(attr_type, ifcopenshell.ifcopenshell_wrapper.select_type):
+                    types_to_process.extend([t for t in attr_type.select_list()])
+                else:
+                    entity_attr_types.append(attr_type.name())
+                types_to_process.remove(attr_type)
 
-        if el.name() in attr_types:
+        if el.name() in entity_attr_types:
             inverse_attrs.append(a)
     return inverse_attrs