Re: [PATCH] Cygwin has trustable filemode

> Ramsay Jones <ramsay@ramsay1.demon.co.uk> writes:
>
>> Mark Levedahl wrote:
>>> The supported Cygwin distribution on supported Windows versions provides
>>> complete support for POSIX filemodes, so enable this by default.
>>> ...
>>> Historical notes: Cygwin version 1.7 supports Windows-XP and newer, thus
>>> dropped support for all OS variants that lack NTFS and/or ...
>>> ...  Thus, POSIX filemode support
>>> could not be expected by default on a Cygwin 1.5 installation, but is
>>> expected by default on a 1.7 installation.
>>>
>> Again, I have to ask; should you not "revert" commit c869753e ("Force core.filemode
>> to false on Cygwin.", 30-12-2006)?  After this commit, there is no longer any user
>> of the NO_TRUSTABLE_FILEMODE build variable, and no real prospect of anyone else
>> wanting to use it.
> Thanks for raising this point.
>
> Reading c869753e once again:
>
>      The issue is that Cygwin and NTFS correctly supports the
>      executable mode bit, and Git properly detected that, but most
>      native Windows applications tend to create files such that
>      Cygwin sees the executable bit set when it probably shouldn't
>      be.
>
> In other words, the reason why "NO_TRUSTABLE_FILEMODE" was added was
> not because the Cygwin did not give us reliable filemodes.  It was
> because tools outside the control of Git and/or Cygwin that users
> use tend to misbehave, even when the working tree is on a filesystem
> on which Cygwin can give us trustable filemodes.
>
> So "1.7 always supports core.filemodes correctly because it no
> longer works on filesystems without trustable filemodes" is not a
> valid reason to justify Mark's change.
>
> There are only three possible ways going forward, I think:
>
>   (A) Drop Mark's patch, and do nothing else, because breakages of
>       other people's programs are not fixed by Cygwin 1.7's improved
>       filesystem support, and users still use those mode breaking
>       programs written by others;
>
>   (B) Drop Mark's patch, and revert c869753e, because it is not the
>       business of our project to sweep breakages of other people's
>       tools under the rug by crippling our software; or
>
>   (C) Drop NO_TRUSTABLE_FILEMODE for _all_ versions of Cygwin,
>       declaring that the spirit of c869753e to work around bugs in
>       other people's software by crippling Git is justified, but that
>       it is no longer necessary on Cygwin because people do not use
>       such misbehaving third-party tools anymore.
>
> These three each rely on its own precondition; I suspect it is
> likely that (A)'s is the most accurate description of the real world.
>