X11 bugs; XWarpPointer and FullScreen

[Olivier Fourdan]

Hi,

On Wed, 27 Nov 2019 at 09:16, <imagtek at gmail.com> wrote:
>
> XWarpPointer does not work on RedHat/Centos-8. The same code works
> flawlessly on WSL / Ubuntu 18.04 using '
> www.sourceforge.net/projects/vcxsrv.
>
> FullScreen mode works under RedHat/Centos-8 but is broken under vcxsrv.

I have no idea what vcxsrv is, sorry.

> This is impacting my product development and support.

Are you sure you're running Xorg? Red Hat Enterprise Linux 8 (and I
guess Centos 8) uses Wayland by default, not Xorg. You can change back
to Xorg in the login screen though.

Under Wayland, a client cannot control the pointer, so
`XWarpPointer()` which goes through Xwayland under Wayland will not
work in the general case, that's to be expected.

Xwayland however can under some circumstances emulate `XWarpPointer()`
using the Wayland “relative pointer” protocol [1] but this is limited
to some specific cases (like, the cursoe must be invisible, the window
must have pointer focus, etc.) on purpose (basically for games) on
purpose.

HTH,
Olivier

[1] https://gitlab.freedesktop.org/wayland/wayland-protocols/tree/master/unstable/relative-pointer
[2] https://gitlab.freedesktop.org/xorg/xserver/commit/a6e85e633