duplicate keys in JSON objects are lost

[dkg]

in tshark.py, _duplicate_object_hook is defined and declared to "Make lists out of duplicate keys". However, it doesn't make lists out of duplicate keys:

def _duplicate_object_hook(ordered_pairs):
    """Make lists out of duplicate keys."""
    json_dict = {}
    for key, val in ordered_pairs:
        existing_val = json_dict.get(key)
        if not existing_val:
            json_dict[key] = val
        else:
            # There are duplicates without any data for some reason, if it's that - drop it
            # Otherwise, override
            if val.get("properties") != {}:
                json_dict[key] = val

    return json_dict

This was introduced in 862e4a6 -- which doesn't have enough in the git commit message to explain why it is done this way.

[dkg]

Note that p.3 of the json standard says:

The JSON syntax does not impose any restrictions on the strings used as names, does not require that name strings be unique, and does not assign any significance to the ordering of name/value pairs. These are all semantic considerations that may be defined by JSON processors or in specifications defining specific uses of JSON for data interchange