[PATCH] dpkg & dpkg_deb: don't depend on FEATURE_SEAMLESS_GZ

[Kang-Che Sung]

On Sat, Jan 7, 2017 at 2:31 AM, Jody Bruchon <jody at jodybruchon.com> wrote:
> On 2017-01-06 13:23, Denys Vlasenko wrote:
>>
>> On Fri, Jan 6, 2017 at 4:18 AM, Kang-Che Sung <explorer09 at gmail.com>
>> wrote:
>>>
>>> CONFIG_DPKG and CONFIG_DPKG_DEB unnecessarily depend on
>>> CONFIG_FEATURE_SEAMLESS_GZ. Worse, it has been using "select" clause,
>>> which would prevent FEATURE_SEAMLESS_GZ from being unselect-able when
>>> using "make config" without a .config file:
>>>
>>>      $ rm .config
>>>      $ make config
>>>      [Answer N to almost every boolean choice, and observe that
>>>      FEATURE_SEAMLESS_GZ cannot be unselected.]
>>>
>>> Because the C code of both dpkg and dpkg-deb are already aware of no-GZ
>>> configuration, it's safe to remove that dependency.
>>
>> My understanding is that .deb files usually use .gz compression,
>> and building dpkg without support for .gz results in a useless tool:
>> there are no .deb files which it can process.
>
> Debian packages support gzip or xz for the control.tar file and a variety of
> common compression formats for the data.tar file.

Yes. And my point is that there's no need to force a gz choice for users.
gz could be deprecated. And sometimes a custom distribution may decide
not to gz-compress its .deb packages at all.

I think it will be better to just *recommend* the gz feature instead. Mention
in the help text:

    Note that most .deb packages compress their metadata
    in gz (control.tar.gz), so you are likely to also enable the
    "understand .gz data" feature above (FEATURE_SEAMLESS_GZ).