Olivier Fourdan de8927e075 xwayland: Init DnD on every Xwayland start
Currently, meta_xwayland_shutdown_dnd() is called from the handler
on_x11_display_closing() triggered from the signal "x11-display-closing"
hooked up from meta_xwayland_init_display().

Once the signal has been triggered, on_x11_display_closing() removes the
signal handler, disconnecting from the signal.

As meta_xwayland_init_display() is called from meta_display_new() which
is issued only once, the signal handler is not restored again.

As a result, meta_xwayland_shutdown_dnd() is not called anymore after
Xwayland has been restarted, but meta_xwayland_init_dnd() will check and
assert that the manager's DND object is NULL.

Basically, restarting Xwayland more that once will trigger an assertion
failure in mutter. That's even more of a problem with autoclose-xwayland
where Xwayland is expected to terminate when there is no meaningful X11
client remaining, which can happen multiple times during the lifetime
of a user session.

To make sure that meta_xwayland_init_display() is called for every new
instance of Xwayland, simply keep the signal hooked in place by not
disconnecting it when triggered.

This reverts commit 9a10b8ff94cc9506a4ecd8ade7489fa9a5af406a.

Even though, originally, this issue was first introduced with commit
b4fe1fdd95d52e8625c66ded1ec7162371dcf32b ("xwayland: Make setup/teardown
a bit more symmetrical") which didn't actually kept 'x11-display-setup'
and 'x11-display-closing' connected.

Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/2168
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2339>
2022-03-30 13:51:26 +00:00
2022-03-25 11:48:42 +00:00
2022-03-28 16:17:21 +00:00

Mutter

Mutter is a Wayland display server and X11 window manager and compositor library.

When used as a Wayland display server, it runs on top of KMS and libinput. It implements the compositor side of the Wayland core protocol as well as various protocol extensions. It also has functionality related to running X11 applications using Xwayland.

When used on top of Xorg it acts as a X11 window manager and compositing manager.

It contains functionality related to, among other things, window management, window compositing, focus tracking, workspace management, keybindings and monitor configuration.

Internally it uses a fork of Cogl, a hardware acceleration abstraction library used to simplify usage of OpenGL pipelines, as well as a fork af Clutter, a scene graph and user interface toolkit.

Mutter is used by, for example, GNOME Shell, the GNOME core user interface, and by Gala, elementary OS's window manager. It can also be run standalone, using the command "mutter", but just running plain mutter is only intended for debugging purposes.

Contributing

To contribute, open merge requests at https://gitlab.gnome.org/GNOME/mutter.

It can be useful to look at the documentation available at the Wiki.

Coding style and conventions

See HACKING.md.

Git messages

Commit messages should follow the GNOME commit message guidelines. We require an URL to either an issue or a merge request in each commit. Try to always prefix commit subjects with a relevant topic, such as compositor: or clutter/actor:, and it's always better to write too much in the commit message body than too little.

Default branch

The default development branch is main. If you still have a local checkout under the old name, use:

git checkout master
git branch -m master main
git fetch
git branch --unset-upstream
git branch -u origin/main
git symbolic-ref refs/remotes/origin/HEAD refs/remotes/origin/main

License

Mutter is distributed under the terms of the GNU General Public License, version 2 or later. See the COPYING file for detalis.

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