bug#6918: Colors of xbm image are swapped on Windows

[Stefan Kangas <stefan@marxist.se>]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Jason Rumney <jasonrumney@gmail.com>
>> Date: Thu, 10 Oct 2019 19:59:46 +1300
>> Cc: Lars Ingebrigtsen <larsi@gnus.org>, kzhr@d1.dion.ne.jp, 6918@debbugs.gnu.org
>>
>> On Fri, 27 Sep 2019 at 17:30, Eli Zaretskii <eliz@gnu.org> wrote:
>> >
>> > How do you suggest to test the proposed change, to make sure it
>> > doesn't break something else?  Any pointers to those monochrome PBM
>> > icons used in the past, for example, or any other files?
>>
>> Are the icons not still under etc/images?  It looks like they are to me.
>
> There are *.pbm icons in etc/images/, and then there are *.ico files
> in nt/icons/.  Which ones did you have in mind?

(That was in 2019, but Jason never replied back.)

My guess is the *.pbm icons - as far as I can tell, Emacs doesn't have
support for the .ico ones without ImageMagick.  The patch is also about
the pbm code, AFAICT.  So I would check them.

>> IIRC, it was gnus that was missing xpm versions, so those were the
>> icons that were actually used in practice, but it was many years
>> (decades even) ago, and you might have to dig through the git history
>> to find the exact icons.
>
> So you are saying that if, after the change, the PBM icons we have in
> the repository display fine, the change is OK?

I understand him to be saying that.

> As for digging through VCS history: I'm not sure I understand what
> should I be looking for there.  Can you elaborate a bit?

Again, I can only interpret what is written, but I think he means here
that the icons may or may not still exist in the git repository.
However, AFAICT they do still exist, under etc/images.  We haven't
removed any relevant images from there as can be seen with this command:

    git --no-pager log --diff-filter=D --summary etc/images