See #5799. Allow merging unnamed styles.

Styles are special because their names aren't critically semantic. It's
more to do with the style definition.

src/bonsai/bonsai/bim/module/debug/operator.py

@@ -713,9 +713,9 @@ class MergeIdenticalObjects(bpy.types.Operator, tool.Ifc.Operator):
             return {"CANCELLED"}
         plural_object_type = f"{object_type.lower()}s"
         if merged_data:
-            print(f"Merged {plural_object_type}:")
             for element_type, element_names in merged_data.items():
-                print(f"- {element_type}: {', '.join(element_names)}")
+                names = ", ". join([n or "Unnamed" for n in element_names])
+                print(f"- {element_type}: {names}")
         merged = sum(len(v) for v in merged_data.values())
 
         msg = " See system console for details." if merged else ""

src/bonsai/bonsai/tool/debug.py

@@ -131,8 +131,8 @@ class Debug(bonsai.core.tool.Debug):
             # Calculate hashes.
             hash_to_elements: defaultdict[int, list[ifcopenshell.entity_instance]] = defaultdict(list)
             for element in elements:
-                # Ignore unnamed elements as they may be not safe to merge.
-                if not element.Name:
+                # Except for styles, ignore unnamed elements as they may be not safe to merge
+                if object_type != "STYLE" and not element.Name:
                     continue
                 element_hash = get_hash(element)
                 hash_to_elements[element_hash].append(element)