Wrong determination of multi-chunk file name.

[tteko]

I tried to unpack two files i have: sde_pack_lang_english_dir.vpk and sde_pack_lang_english_000.vpk by command:

vpk -x . sde_pack_lang_english_dir.vpk

IOError: [Errno 2] No such file or directory: 'sde_pack_lang__000.vpk'

I guess what is about the third underscore character in VPK file name?