bug#47035: 27.1; XBM wrong display with :rotation 90/270

[Alan Third]

On Wed, Mar 10, 2021 at 04:12:48PM +0100, Lars Ingebrigtsen wrote:
> ynyaaa@gmail.com writes:
> 
> > Rotated XBM images may be displayed wrongly.
> > The original image in the form below is a horizontal stripe.
> > But the images rotated 90 or 270 degrees are displayed as solid black
> > squares.
> >
> > (let ((xbm (unibyte-string 255 0 255 0 255 0 255 0)))
> >   (dolist (r '(0 90 180 270))
> >     (insert-image (create-image xbm 'xbm t :width 8 :height 8
> >                                 :rotation r :scale 1))))
> 
> I'm unable to reproduce this in Emacs 27.1 (or Emacs 28) on
> Debian/bullseye, so it may be a Windows-specific problem.

I suspect this is the same problem as bug#46556.
-- 
Alan Third