If one would end up with an actor attached to mapped actor, where the
attached actor doesn't itself have an up to date stage view list while
listening on the stage for updating, when clearing the stage views of
the list, anything that would query the stage views list at this time
would end up accessing freed memory.
This could happen if
1) An actor was added to a newly created container actor attached to
the stage
2) The actor got a timeline attached to it
3) The actor was moved to a container that already was mapped
4) A hotplug happened
After (1) both the container and actor would not have any stage views.
After (2) the timeline would listen on the stage for stage views
updates. After (3) the actor would still listen on the stage for stage
views updates. When (4) happened, the actor would be signalled when the
stage got its stage view cleared, at which point it would traverse up
its actor's tree finding an appropriate stage view to base its animation
on. The problem here would be that it'd query the already mapped
container and its yet-to-be-cleared stage view list, resulting in
use-after free, resulting in for example the following backtrace:
0) g_type_check_instance_cast ()
1) CLUTTER_STAGE_VIEW ()
2) clutter_actor_pick_frame_clock ()
3) clutter_actor_pick_frame_clock ()
4) update_frame_clock ()
5) on_frame_clock_actor_stage_views_changed ()
6) g_closure_invoke ()
7) signal_emit_unlocked_R ()
8) g_signal_emit_valist ()
9) g_signal_emit ()
10) clear_stage_views_cb ()
11) _clutter_actor_traverse_depth ()
12) _clutter_actor_traverse ()
13) clutter_actor_clear_stage_views_recursive ()
14) clutter_stage_clear_stage_views ()
...
Avoid this issue by making sure that we don't emit 'stage-views-changed'
signals while the actor tree is in an invalid state. While we now end up
traversing tree twice, it doesn't change the Big-O notation. It has not
been measured whether this has any noticible performance impact.
Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/1950
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2025>
Certains keys (such as ~ and |) are in the keyboard map behind the
second shift level. This means in order for them to be input, the
shift key needs to be held down by the user.
The GNOME Shell on-screen keyboard presents these keys separately on
a page of keys that has no shift key. Instead, it relies on mutter
to set a shift latch before the key event is emitted. A shift latch
is a virtual press of the shift key that automatically gets released
after the next key press (in our case the ~ or | key).
The problem is using a shift latch doesn't work very well in the face
of key repeat. The latch is automatically released after the first
press, and subsequent repeats of that press no longer have shift
latched to them.
This commit fixes the problem by using a shift lock instead of a shift
latch. A shift lock is never implicitly released, so it remains
in place for the duration of key repeat.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2045>
The `guess_candidates()` function scores each display that an input
device could be mapped to and then uses the `sort_by_score()` comparator
to find the best option. The function expects the list to be sorted from
best to worst, but the comparator currently sorts them in the opposite
order. This causes the function to end up returning the _worst_ match
rather than the the best. This commit reverses the sort order of the
comparator so that the best display can be returned as intended.
Closes: #1889
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1934>
This does two things to frown upon:
- Modifies ClutterEvent structs, while the effort is to have those
completely opaque, and readonly after creation from the input
thread side.
- Stores state in the ClutterInputDevice struct, event though those
are also considered static after creation, managed by the input
thread, etc.
Stop doing that. This makes all events just forwarded as-is in
the ClutterStage/clutter-main.c code.
Handling of click count sounds like material for a ClutterGestureAction
(or perhaps ClutterClickAction), all of both callers now do it in place
at the moment, while gestures lack a better state tracking and management.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2024>
This will not try the captured-event shenanigans to emulate grab
behavior, instead relying on event delivery being influenced by
other grab mechanisms.
While at it, improve handling of additional touchpoints by
cancelling the click action right away, as the differences in
event handling make this unwanted behavior surface.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2024>
By default, the pan action performs matrix translations on the
child widget. Nobody wants that (or, nobody wants *just* that).
It's cleaner not to mix mechanism and effect in ClutterGestureAction
subclasses, so drop this base implementation, and change the signal
accumulator so it's more similar to event signals (not that it's
used any longer, anyway).
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2024>
Mutter already calculates and tracks the damage rectangles to redraw
only areas of the screen that change since the last time a buffer was
used.
This patch extends this by using the EGL_KHR_partial_update extension to
inform the GPU in advance that only those areas will be changed, which
may allow for further optimization.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2023>
Add support for a cogl function to set the damage_region on an onscreen
framebuffer.
The goal of this is to enable using the EGL_KHR_partial_update extension
which can potentially reduce memory bandwidth usage by some GPUs,
particularly on embedded GPUs that operate on a tiling rendering model.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2023>
Defining valid values makes
1. changing settings less error prone
2. sure they are discoverable.
This does reset the values once on update, but fortunately does *not*
change the way to set the values. Thus e.g. enabling fractional scaling
via terminal command still works as before and internet guides stay valid.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1961>
This will make clients immediately aware of the output disappearing,
while still allowing for a grace period of 10 seconds for attempting to
bind to it before it turning into a protocol error. This API added as
part of wayland 1.18.
This requires us to not add the output resource to the output resource
list, if the output was made inert. This effectively makes the resource
useless, but that is harmless, since shortly after, the client will
clean it up anyway.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1796>
This will be crucial when we start to remove the global directly when an
output is removed, as that means Xwayland might have removed the output
before we managed to get our queries in.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1796>
We setup Xwayland in an early phase of the X11 display, before we had a
MetaX11Display, and teared down in a couple of places happening when
tearing down the Xwayland integration if the X server died or
terminated. It was a bit hard to follow what happened and when it
happened. Attempt to clean this up a bit, with things being structured
as follows:
* Early during X11 display connection setup, only setup the rudimentary
X11 hooks, being the libX11 error callbacks, and adding the local
user to XHost.
* Move "initialize Xwayland component" code to a new
'x11-display-setup' signal handler. Things setup here are cleaned up
in the 'x11-display-closing' handler.
* Connect to 'x11-display-setup' and 'x11-display-closing' up front,
and stay connected to these two.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1796>
