Node does not exist for SceneGroupItemBlock: None

[Azeirah]

Traceback (most recent call last):
  File "/usr/local/lib/python3.10/runpy.py", line 196, in _run_module_as_main
    return _run_code(code, main_globals, None,
  File "/usr/local/lib/python3.10/runpy.py", line 86, in _run_code
    exec(code, run_globals)
  File "/app/remarks/__main__.py", line 151, in <module>
    main()
  File "/app/remarks/__main__.py", line 147, in main
    run_remarks(input_dir, output_dir, **args_dict)
  File "/app/remarks/remarks.py", line 96, in run_remarks
    process_document(metadata_path, out_path, doc_type, **kwargs)
  File "/app/remarks/remarks.py", line 271, in process_document
    (ann_data, has_ann_hl), version = parse_rm_file(ann_rm_file)
  File "/app/remarks/conversion/parsing.py", line 259, in parse_rm_file
    return parse_v6(file_path), "V6"
  File "/app/remarks/conversion/parsing.py", line 128, in parse_v6
    dims = determine_document_dimensions(file_path)
  File "/app/remarks/conversion/parsing.py", line 183, in determine_document_dimensions
    build_tree(tree, blocks)
  File "/app/.venv/lib/python3.10/site-packages/rmscene/scene_stream.py", line 773, in build_tree
    raise ValueError(
    ValueError: Node does not exist for SceneGroupItemBlock: None`

def build_tree(tree: SceneTree, blocks: Iterable[Block]):
    for b in block:
        if ...:
            ...
        elif isinstance(b, SceneGroupItemBlock):
            # Add this entry to children of parent_id
            node_id = b.item.value
            # if node_id == None:
                # continue
            if node_id not in tree:
                raise ValueError(
                    "Node does not exist for SceneGroupItemBlock: %s" % node_id
                )
            item = replace(b.item, value=tree[node_id])
            tree.add_item(item, b.parent_id)

Given that the value in the SceneGroupItemBlock is a tp.Optional[CrdtId] it's defined that it's ok to be None?

I added the commented continue if None code and there are no further errors in the document.

Am I correct in assuming it's ok to just skip it if it's None given that the value is optionally typed?

[Azeirah]

@ricklupton I'm learning 😄

[ricklupton]

I'd expect in this case that the b.item.deleted_length was nonzero, and this was a deleted group that is no longer part of the drawing? If so it makes sense that node_id could be None and your fix would be good.