[tz] broken compression in archive

Zefram zefram at fysh.org
Wed Nov 1 03:11:07 UTC 2017

I'm doing some work on how to access historical tzdb versions, and I
noticed that tz{code,data}94d.tar.Z are, despite their names, uncompressed
tar files.  To be precise, I refer to the files with these SHA-512 hashes:

9872b757ee3a8bf0ed3de1f0875f878b977b34bd2b60440b23a8c7308a7514d12a5d5d283387973e61b75e1a8eebd27009aab78eee4e12f1f1a5593f71941328  tzcode94d.tar.Z
e1524951a5c261cc8eef1f3adadf5ebf8143293745fda9411a0090d6bb6e19f899dd7a6e55fe2f8f490a167a3da392020e49b369984bc1f5cbed87d664eb58de  tzdata94d.tar.Z

They're unique, in the present archive <ftp://ftp.iana.org/tz/releases/>,
in having a mismatch between format and filename suffix.

I think these files should be replaced, in the archive, with actual
compressed (with compress(1)) versions of these tars, under the same
name, so that the names are no longer misleading and they are in the
same format as the surrounding files.  The other way to make the names
no longer misleading is to rename these files, dropping the ".Z" suffix,
but this approach has the problem that these files would (still) have
a different format from all the other tarballs.

Note that this mismatch is not a mistake made in the original release of
94d, and the replacement that I'm proposing would not erase a record of
the original release files.  The original 94d release was of *gzipped*
tar files, which are not in the present archive.  Actual releases
switched from .Z to .gz at 93g, but the archive files switch at tzdata95c
and tzcode95d.  Obviously someone recompressed the intervening tarballs
somewhere along the chain of custody that led to the present archive, and
it appears that the failure to (re)compress 94d happened in that process.


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