Storage Object Metadata keys not returned in lowercase

[mwidman]

Contrary to the documentation, in 1.9.5, the metadata keys are not returned in lowercase.

In 1.9.3 a metadata submitted as "last_timestamp" or "X-Object-Meta-last-timestamp" would be returned as "last_timestamp"; however, in 1.9.5 it is now returned as "X_Object_Meta_Last_Timestamp". Note the inclusion of the prefix AND the conversion to initial uppercase after each '_'.

I don't mind the inclusion of the prefix as that is how it worked prior to 1.9.3 (see this comment regarding that: #549 (comment)); however, sending key back not in lowercase is contrary to the docs as previously stated.

I have tracked it down to a bug in the code on line 2118 in object_storage.py where the key "hkey" is converted to lowercase "lowkey" but that converted key is not used:

        for hkey, hval in list(resp.headers.items()):
            lowkey = hkey.lower()  # Converted but not used as the return value
            if lowkey.startswith(low_prefix):
                cleaned = hkey.replace(low_prefix, "").replace("-", "_")
                ret[cleaned] = hval
        return ret