With EI support wired to XTEST, and oeffis being enabled unconditionally
means that Xwayland will always go through the XDG portal for XTEST when
supported.
While this the intended behavior for the general use case of Xwayland
running rootless on a desktop compositor, that breaks when Xwayland is
running on a nested compositor, because the portal is for the entire
session and not limited to the nested Wayland compositor.
Xwayland itself, as a regular Wayland client, has no way to tell that it
is running on a nested compositor.
So to keep backward compatibility with existing (and also common) use
cases such as nested compositors, best is to disable support for the XDG
portal by default, and add a new command line option "-enable-ei-portal"
for the Wayland compositors (who spawn Xwayland rootless) to explicitly
enable support for the input emulation XDG portal in Xwayland.
A Wayland compositor running nested should not use that command line
option with Xwayland.
Signed-off-by: Olivier Fourdan <ofourdan@redhat.com>
Reviewed-by: Joshua Ashton <joshua@froggi.es>
Fixes: a1333342 - xwayland: Add XTEST support using EIS
Closes: https://gitlab.freedesktop.org/xorg/xserver/-/issues/1586
See-also: https://gitlab.gnome.org/GNOME/mutter/-/issues/3047
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