Pixmap cursor bug?

[Adam Jackson]

The patches sound great, please send them on. I may not have time to merge
them myself but I can at least get them into gitlab with some commentary
for the next adventurous soul.

- ajax

On Wed, Dec 20, 2023 at 3:27 AM <mouse at mojatatu.com> wrote:

> I tried to send a HELP request to xorg-request but it disappeared
> without any trace as far as I can tell, so I'm not sure whether I can
> subscribe.  If anyone sees this, _something_ got through, though.
>
> There's a bug I've seen in various X servers.  I *think* they're all
> derived from X.org code, and I suspect this is moderately widespread;
> I've seen it on recent Ubuntu, recent RaspOS, and old NetBSD.  I wrote
> a tiny test (ftp.rodents-montreal.org:/mouse/misc/cursor-bug.c - also
> available over HTTP as well, though I'm not sure what Content-Type:
> it'll be served as) and people on NetBSD's tech-x11 report it on recent
> NetBSD as well, on some, but only some, hardware.
>
> The bug is that creating a pixmap cursor (a CreateCursor request) with
> a mask of None typically extends the source pixmap to the right with
> server-dependent data (typically background pixels) to a width such as
> 16 or 32 pixels.  See the comment header on the test program for more.
>
> I wrote patches to fix this for two server versions (the ones that
> shipped with NetBSD 4.0.1/i386 and 5.2/amd64).  I can certainly send
> those patches if anyone wants them; they are old, but if that part of
> ProcCreateCursor is unchanged since then they might be a useful
> starting point (though I do have low-to-negative confidence I got the
> code right for other architectures).
>
> /~\ The ASCII                             Mouse
> \ / Ribbon Campaign
>  X  Against HTML
> / \ Email!                          mouse at mojatatu.com
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.x.org/archives/xorg/attachments/20240123/453eeb69/attachment.htm>