bug#73082: 30; Inconsistent Stipple Support

[Po Lu via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

Eli Zaretskii <eliz@gnu.org> writes:

>> Cc: Po Lu <luangruo@yahoo.com>
>> From: JD Smith <jdtsmith@gmail.com>
>> Date: Fri, 6 Sep 2024 17:58:02 -0400
>> 
>> (let* ((w (window-font-width))
>>        (stipple `(,w 1 ,(apply #'unibyte-string (make-list (/ (+ w 7) 8) 186)))))
>>   (insert "\n" (propertize (concat  (make-string 15 ?\s)
>> 				    "THIS IS A TEST"
>> 				    (make-string 15 ?\s))
>>                            'face `(:background "red" :foreground "blue" :stipple ,stipple))))
>> 
>> Only some Emacs 30 builds correctly render this simple stipple.  There has been some progress on :stipple support recently, but it remains incomplete.  To my knowledge, the current situation for :stipple support in Emacs 30 is as follows:
>> NS (partially working): Commit ef6ffbdc79 from last May provided a partial fix, but stipples are black and white only (bug#70712)
>> Windows (working?): patched in June (bug#71159)
>> PGTK (working): incorrect stipple display patched July, 2023 (bug#64969)
>> GTK, non-Cairo (working): appears to be working correctly
>> GTK + Cairo (not working uniformly): Stipples are reported to be missing with some Cairo builds of Emacs 30
>> Other X11 builds (?): Unsure if these are supported (but suspect they are given the legacy of stipple)
>
> The MS-Windows build of the emacs-30 branch here shows the display you
> expected.

You should add Haiku and Android to your list, as Emacs supports
stipples on both of these window systems.  (And on the latter they were
in fact implemented for your package.)

I am also interested to know precisely which Cairo builds fail to
display them, the stipple implementations being virtually identical
across the PGTK and the X + Cairo builds.