Currently, the maximum size for a mouse pointer bitmap for screen
casting is 64x64 pixels.
However, this limit is hit way too often as it is way too low and
results in crashes in either gnome-remote-desktop or mutter.
For example: The a11y settings in g-c-c allow setting a larger pointer
bitmap in order to increase the visibility of the mouse pointer.
With the current limit of 64x64 pixels it is not possible to use the
larger variants of the default mouse pointer bitmap, without
experiencing any crash.
Another way to hit the limit is when display scaling is used or some
game uses a custom (large) mouse pointer bitmap.
The VNC backend in gnome-remote-desktop does not seem to have a maximum
pointer bitmap size.
The RDP backend on the other hand has a maximum pointer bitmap size at
384x384.
Use this size (384x384) as maximum size instead of the current 64x64
size for mouse pointer bitmaps to avoid crashes in mutter and
gnome-remote-desktop and to ensure that bigger mouse pointer bitmaps
can be used.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1414
It is linear config manager created when ensuring configuration.
However, the switch config is not set as LINEAR, but left as UNKNOWN.
This leads switch mode OSD always shows "Join Displays" icon, rather
than the next icon which is "External Only" after connect an external
display and press Super+P once at first time since mutter starts.
This patch moves switch config setting into
meta_monitor_config_manager_create_linear() (and the sibling functions)
to well prepare the monitors config and avoid missing settings.
This is a regression introduced by 149e4d6934.
Fixes: https://gitlab.gnome.org/GNOME/mutter/-/issues/1362
The delete event was used for signalling the close button was clicked on
clutter windows. Being a compositor we should never see these, unless
we're running nested. Remove the plumbing of the DELETE event and just
directly call meta_quit() when we see it, if we're running nested.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1364
We checked if we were using the usig the X11 backend to decide when to
deal with a11y event posting - in order to make the clutter code less
windowing system dependent, make this check a check whether we're a
display server or not, in contrast to a window/compositing manager
client. This is made into a vfunc ot ClutterBackendClass, implemented by
MetaClutterBackendNative and MetaClutterBackendX11.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1364
Flip flop resize, which is the result of respecting ConfigureNotify
makes test annoyingly racy, as one cannot do
clutter_actor_set_size (stage, 1024, 768);
wait_for_paint (stage);
g_assert_assert (clutter_actor_get_width (stage) == 1024);
The reason for this is any lingering ConfigureNotify event that might
arrive in an inconvenient time in response to some earlier resize.
In order to not risk breaking any current behavior in the X11 CM case
(running as a compositing window manager), only avoid changing the stage
size in response to ConfigureNotify when running nested.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1404
This aims to make sure a view and its resources are destroyed when it
should. Using references might keep certain components (e.g frame clock)
alive for too long.
We currently don't take any long lived references to the stage view
anywhere, so this doesn't matter in practice, but this may change, and
will be used by a to be added test case.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1404
Without doing this, we'd use the same sprite that was last set by
mutter, most likely a leftptr cursor, and fail to update when e.g.
moving the pointer above a text entry and the displayed cursor updated
to a cursor position marker.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1391
The displayed cursor is the one displayed on the screen, e.g. via the
hardware cursor plane, by Xorg, or using the stage overlay.
When screen recording under X11, we don't get a stream of pointer and
cursor updates, as they might be grabbed by some other client. Because
of this, the cursor tracker or cursor renderer are not kept up to date
with positional and cursor state.
To be able to use the stage overlays when recording, we need to be able
to update the overlay without updating the displayed cursor, as we
shouldn't update the X server with cursor state we just retrieved from
it.
Thus, to achieve this, create a separate overlay cursor pointer. When
being a display server, they are always the same, but when using X11,
during screen recording, the overlay one will be polled at a fixed
interval to get a somewhat up to date state.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1391
Always force-track the cursor position (so that the X11 backend can keep
it up to date), and if the cursor wasn't part of the sampled
framebuffer when reading pixels into CPU memory, draw it in an extra
pass using cairo after the fact. The cairo based cursor painting only
happens on the X11 backend, as we otherwise inhibit the hw cursor.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1391
On X11 we won't always receive cursor positions, as some other client
might have grabbed the pointer (e.g. for implementing a popup menu). To
make screen casting show a somewhat correct cursor position, we need to
actively poll the X server about the current cursor position.
We only really want to do this when screen casting or taking a
screenshot, so add an API that forces the cursor tracker to track the
cursor position.
On the native backend this is a no-op as we by default always track the
cursor position anyway.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1391
Only when the cursor isn't handled by the backend is the overlay made
visible. This is intended to be used when painting the stage to an
offscreen using clutter_stage_paint_to_(frame)buffer() in a way where
the cursor is always included.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1391
Detect displays marked as 'non-desktop' by the kernel and skip them when
creating the outputs. Mutter is not able to render images that are shown
properly on those devices anyway.
This avoids lighting up attached VR HMDs and showing the GDM login
screen between the eyes in a VR HMD instead of on the monitor.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1393
Intended to be used to pass state from screen cast clients down the
line. The first use case will be a boolean whether a screen cast is a
plain recording or not, e.g. letting the Shell decide whether to use a
red dot as the icon, or the generic "sharing" symbol.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1377
The new "id" properties for the MetaCrtc* and MetaOuput* objects are 64-bit
values, so take care to pass 64-bit values when calling g_object_new.
Fixes https://gitlab.gnome.org/GNOME/mutter/-/issues/1343.
When using its EGLStream-based presentation path with the proprietary NVIDIA
driver, mutter will use a different function to process page flips -
custom_egl_stream_page_flip. If that fails due to an EBUSY error, it will
attempt to retry the flip. However, when retrying, it unconditionally uses the
libdrm-based path. In practice, this causes a segfault when attempting to
access plane_assignments->fb_id, since plane_assignments will be NULL in the
EGLStream case. The issue can be reproduced reliably by VT-switching away from
GNOME and back again while an EGL application is running.
This patch has mutter also use the custom page flip function when retrying the
failed flip.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1375
Instead of blindly hoping that `$INCLUDE` contains the parent directory
of `gsettings-desktop-schemas`.
Because `gsettings-desktop-schemas.pc` says:
```
Cflags: -I/SOME/DIRECTORY/gsettings-desktop-schemas
```
Which means to include the version that Meson has configured you need
to drop the directory prefix and only `#include <gdesktop-enums.h>`.
This fixes a build failure with local installs triggered by 775ec67a44
but it's also the right thing to do™.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1370
During animation or other things that cause multiple frames in a row
being painted, we might skip recording frames if the max framerate is
reached.
Doing so means we might end up skipping the last frame in a series,
ending with the last frame we sent was not the last one, making things
appear to get stuck sometimes.
Handle this by creating a timeout if we ever throttle, and at the time
the timeout callback is triggered, make sure we eventually send an up to
date frame.
This is handle differently depending on the source type. A monitor
source type reports 1x1 pixel damage on each view its monitor overlaps,
while a window source type simply records a frame from the surface
directly, except without recording a timestamp, so that timestamps
always refer to when damage actually happened.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1361
Now that we don't use the record function to early out depending on
implicit state (don't record pixels if only cursor moved for example),
let it simply report an error when it fails, as we should no longer ever
return without pixels if nothing failed.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1361
Both do more or less the same but with different methods - one puts
pixels into a buffer using the CPU, the other puts pixels into a buffer
using the GPU.
However, they are behaving slightly different, which they shouldn't.
Lets first address the misleading disconnect in naming, and later we'll
make them behave more similarly.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1361
Replace the default master clock with multiple frame clocks, each
driving its own stage view. As each stage view represents one CRTC, this
means we draw each CRTC with its own designated frame clock,
disconnected from all the others.
For example this means we when using the native backend will never need
to wait for one monitor to vsync before painting another, so e.g. having
a 144 Hz monitor next to a 60 Hz monitor, things including both Wayland
and X11 applications and shell UI will be able to render at the
corresponding monitor refresh rate.
This also changes a warning about missed frames when sending
_NETWM_FRAME_TIMINGS messages to a debug log entry, as it's expected
that we'll start missing frames e.g. when a X11 window (via Xwayland) is
exclusively within a stage view that was not painted, while another one
was, still increasing the global frame clock.
Addititonally, this also requires the X11 window actor to schedule
timeouts for _NET_WM_FRAME_DRAWN/_NET_WM_FRAME_TIMINGS event emitting,
if the actor wasn't on any stage views, as now we'll only get the frame
callbacks on actors when they actually were painted, while in the past,
we'd invoke that vfunc when anything was painted.
Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/903
Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/3https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1285
This also changes the view construction path used by the renderer view
to use the new 'add_view()' function, meaning we have a common entry
point for views into the renderer, which will be useful later on.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1285
Before we'd create the view in init(), then continue poking at it in
realize(). Move all of the screen stage view initialization to
realize(), as that's when we have all the dependent state available.
This is possible since there is nothing needing it until realizing.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1285
The clutter "thread" repaint callback are not tied to painting, but
indirectly to updating. What the cursor renderer cares about is when we
actually painted, as this is related to the OpenGL fallback paths.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1285
The mutexes was used by ClutterTexture's async upload and to match GDK's
mutexes on X11. GDK's X11 connection does not share anything with
Clutter's, we don't have the Gdk Clutter backend left, and we have
already removed ClutterTexture, so lets remove these mutexes as well.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1285
The native backend had a plain counter, and the X11 backend used the
CoglOnscreen of the screen; change it into a plain counter in
ClutterStageCogl. This also moves the global frame count setting to the
frame info constuctor.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1285
We currently have mutter set a global frame counter on the frame info in
the native backend, but in order to do this from clutter, change the
frame info construction from being implicitly done so when swapping
buffers to having the caller create the frame info and passing that to
the swap buffers call.
While this commit doesn't introduce any other changes than the API, the
intention is later to have the caller be able to pass it's own state
(e.g. the global frame count) along with the frame info.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1285
We had time unit conversion helpers (e.g. us2ms(), ns2us(), etc) in
multiple places. Clean that up by moving them all to a common file. That
file is clutter-private.h, as it's accessible by both from clutter/ and
src/.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1285
Currently unused, but it's intention is to use as a initial refresh rate
for a with the stage view associated frame clock. It defaults to 60 Hz
if nothing sets it, but the native backend sets it to the associated
CRTCs current mode's refresh rate.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1285
We'd check if there was any queued redraw on the stage, but this is
inappropriate for two reasons:
1) A monitor and area screen cast source only cares about damage on a
subset of the stage.
2) The global pending-redraw is going away when paint scheduling will be
more view centric.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1285
Add private API to ClutterBackend to set a fallback resource scale
available to Clutter. This API will be used for "guessing" the
resource-scale of ClutterActors in case the actor is not attached to a
stage or not properly positioned yet.
We set this value from inside mutters MetaRenderer while creating new
stage-views for each logical monitor. This makes it possible to set the
fallback scale to the scale of the primary monitor, which is the monitor
where most ClutterActors are going to be positioned.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1276
The portal API requires a screencast session only for absolution motion
with remote desktop, other methods including relative motion do not
require a screencast session.
There is no reason to be more strict than the API actually is, check for
a screencast session only when required, like for absolute motion events
and touch events.
Tested with https://gitlab.gnome.org/snippets/1122
Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/1307
This avoids some issues which could happen on some setups[0] due to
meta-native-renderer.c:dummy_power_save_page_flip →
meta_onscreen_native_swap_drm_fb implicitly turning of the primary
plane (by destroying the KMS framebuffer assigned to it):
* drmModeObjectSetProperty could return an "Invalid argument" error
between setting a non-empty cursor with drmModeSetCursor(2) and
enabling the primary plane again:
Failed to DPMS: Failed to set connector 69 property 2: Invalid argument
(This was harmless other than the error message, as we always re-set
a mode on the CRTC after setting the DPMS property to on, which
enables the primary plane and implicitly sets the DRM property to on)
* drmModeSetCursor(2) could return an "Invalid argument" error between
setting the DPMS property to on and enabling the primary plane again:
Failed to set hardware cursor (drmModeSetCursor failed: Invalid argument), using OpenGL from now on
[0] E.g. with the amdgpu DC display code.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1240
We delegate the answer through CoglDriverVtable::is_hardware_accelerated
since this is properly a property of the renderer, and not something the
cogl core should know about. The answer given for the nop driver is
admittedly arbitrary, yes it's infinitely fast but no there's not any
"hardware" making it so.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1194
When a touch sequence was rejected, we'd update the event timestamps of
incoming touch events to help with implementing grabs. This was done by
sending a ClientMessage with a counter, and comparing the counter to
decide whether we're seing a replayed event or not.
This had the unforseen consequence that we would potentially end up
destroying all actors including the stage, since, when mutter receives a
ClientMessage event, it would assume that it's a WM_PROTOCOLS event, and
handle it as such. The problem with this approach is that it would
ignore fact that there might be other ClientMessage types sent to it,
for example the touch synchronization one. What could happen is that the
touch count value would match up with the value of the WM_DELETE_WINDOW
atom, clutter would treat this as WM_PROTOCOLS:WM_DELETE_WINDOW, which
it'd translate to clutter_actor_destroy(stage).
Destroying the stage in such a way is not expected, and caused wierd
crashes in different places depending on what was going on.
This commit make sure we only treat WM_PROTOCOLS client messages as
WM_PROTOCOLS client messages effectively avoiding the issue.
This fixes crashes such as:
#0 meta_window_get_buffer_rect (window=0x0, rect=rect@entry=0x7ffd7fc62e40) at core/window.c:4396
#1 0x00007f1e2634837f in get_top_visible_window_actor (compositor=0x297d700, compositor=0x297d700) at compositor/compositor.c:1059
#2 meta_compositor_sync_stack (compositor=0x297d700, stack=<optimized out>, stack@entry=0x26e3140) at compositor/compositor.c:1176
#3 0x00007f1e263757ac in meta_stack_tracker_sync_stack (tracker=0x297dbc0) at core/stack-tracker.c:871
#4 0x00007f1e26375899 in stack_tracker_sync_stack_later (data=<optimized out>) at core/stack-tracker.c:881
#5 0x00007f1e26376914 in run_repaint_laters (laters_list=0x7f1e2663b7d8 <laters+24>) at core/util.c:809
#6 run_all_repaint_laters (data=<optimized out>) at core/util.c:826
#7 0x00007f1e26b18325 in _clutter_run_repaint_functions (flags=flags@entry=CLUTTER_REPAINT_FLAGS_PRE_PAINT) at clutter-main.c:3448
#8 0x00007f1e26b18fc5 in master_clock_update_stages (master_clock=0x32d6a80, stages=0x4e5a740) at clutter-master-clock-default.c:437
#9 clutter_clock_dispatch (source=<optimized out>, callback=<optimized out>, user_data=<optimized out>) at clutter-master-clock-default.c:567
#10 0x00007f1e27e48049 in g_main_dispatch (context=0x225b8d0) at gmain.c:3175
#11 g_main_context_dispatch (context=context@entry=0x225b8d0) at gmain.c:3828
#12 0x00007f1e27e483a8 in g_main_context_iterate (context=0x225b8d0, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at gmain.c:3901
#13 0x00007f1e27e4867a in g_main_loop_run (loop=0x24e29f0) at gmain.c:4097
#14 0x00007f1e2636a3dc in meta_run () at core/main.c:666
#15 0x000000000040219c in main (argc=1, argv=0x7ffd7fc63238) at ../src/main.c:534
and
#0 0x00007f93943c1f25 in raise () at /usr/lib/libc.so.6
#1 0x00007f93943ab897 in abort () at /usr/lib/libc.so.6
#2 0x00007f9393e1e062 in g_assertion_message (domain=<optimized out>, file=<optimized out>, line=<optimized out>, func=0x7f93933e6860 <__func__.116322> "meta_x11_get_stage_window",
#3 0x00007f9393e4ab1d in g_assertion_message_expr ()
#4 0x00007f939338ecd7 in meta_x11_get_stage_window (stage=<optimized out>) at ../mutter/src/backends/x11/meta-stage-x11.c:923
#5 0x00007f939339e599 in meta_backend_x11_cm_translate_device_event (x11=<optimized out>, device_event=0x55bc8bcfd6b0) at ../mutter/src/backends/x11/cm/meta-backend-x11-cm.c:381
#6 0x00007f939339f2e2 in meta_backend_x11_translate_device_event (device_event=0x55bc8bcfd6b0, x11=0x55bc89dd5220) at ../mutter/src/backends/x11/meta-backend-x11.c:179
#7 0x00007f939339f2e2 in translate_device_event (device_event=0x55bc8bcfd6b0, x11=0x55bc89dd5220) at ../mutter/src/backends/x11/meta-backend-x11.c:208
#8 0x00007f939339f2e2 in maybe_spoof_event_as_stage_event (input_event=0x55bc8bcfd6b0, x11=0x55bc89dd5220) at ../mutter/src/backends/x11/meta-backend-x11.c:284
#9 0x00007f939339f2e2 in handle_input_event (event=0x7fff62d60490, x11=0x55bc89dd5220) at ../mutter/src/backends/x11/meta-backend-x11.c:309
#10 0x00007f939339f2e2 in handle_host_xevent (event=0x7fff62d60490, backend=0x55bc89dd5220) at ../mutter/src/backends/x11/meta-backend-x11.c:413
#11 0x00007f939339f2e2 in x_event_source_dispatch (source=<optimized out>, callback=<optimized out>, user_data=<optimized out>) at ../mutter/src/backends/x11/meta-backend-x11.c:467
#12 0x00007f9393e6c39e in g_main_dispatch (context=0x55bc89dd03e0) at ../glib/glib/gmain.c:3179
#13 0x00007f9393e6c39e in g_main_context_dispatch (context=context@entry=0x55bc89dd03e0) at ../glib/glib/gmain.c:3844
#14 0x00007f9393e6e1b1 in g_main_context_iterate (context=0x55bc89dd03e0, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at ../glib/glib/gmain.c:3917
#15 0x00007f9393e6f0c3 in g_main_loop_run (loop=0x55bc8a042640) at ../glib/glib/gmain.c:4111
#16 0x00007f9393369a0c in meta_run () at ../mutter/src/core/main.c:676
#17 0x000055bc880f2426 in main (argc=<optimized out>, argv=<optimized out>) at ../gnome-shell/src/main.c:552
Related: https://gitlab.gnome.org/GNOME/mutter/-/issues/338
Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/951https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1317
Add a method to ClutterSeat that allows peeking the list of input
devices and allow looping through devices a bit faster. The API left is
private so we can make use of peeking the GList internally, but don't
have to expose any details to the outside, which means we'd have to
eventually stick with a GList forever to avoid breaking API.
Since we now have the peek_devices() API internally, we can implement
ClutterSeats public list_devices() API using g_list_copy() on the list
returned by peek_devices().
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1275
Trying to figure out what this comment was actually about, it turns out
that MSC means Media Stream Counter, and as mentioned in an article[0]
is related to DRI3 and the X11 Present extension. Anyway, the comment
has been there raising questions for some years now, I think we can
remove it.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1287
The ID and name are just moved into the instance private, while the rest
is moved to a `MetaCrtcModeInfo` struct which is used during
construction and retrieved via a getter. Opens up the possibility to
add actual sub types.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1287
Just as with MetaOutput, instead of the home baked "inheritance" system,
using a gpointer and a GDestroyNotify function to keep the what
effectively is sub type details, make MetaCrtc an abstract derivable
type, and make the implementations inherit it.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1287
Instead of the home baked "inheritance" system, using a gpointer and a
GDestroyNotify function to keep the what effectively is sub type
details, make MetaOutput an abstract derivable type, and make the
implementations inherit it.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1287
Now set as a property during construction. Only actually set by the
Xrandr backend, as it's the only one currently not supporting all
transforms, which is the default.
While at it, move the 'ALL_TRANFORMS' macro to meta-monitor-tranforms.h.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1287
The output info is established during construction and will stay the
same for the lifetime of the MetaOutput object. Moving it out of the
main struct enables us to eventually clean up the MetaOutput type
inheritence to use proper GObject types.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1287
MetaCrtcInfo and MetaOutputInfo did not represent information about
MetaCrtc and MetaOutput, but the result of the monitor configuration
assignment algorithm, thus rename it to MetaCrtcAssignment and
MetaOutputAssignment.
The purpose for this is to be able to introduce a struct that actually
carries information about the CRTCs and outputs, as retrieved from the
backend implementations.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1287
That is is_presentation, is_primary, is_underscanning and backlight.
The first three are set during CRTC assignment as they are only valid
when active. The other is set separately, as it is untied to
monitor configuration.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1287
It was used during configuration to ensure that we always dealt with
every output and CRTC. Do this without polluting the MetaOutput and
MetaCrtc structs with intermediate variables not used by the
corresponding types themself.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1287
When the stage views the stage is shown on are changed, ClutterStage
currently provides a clutter_stage_update_resource_scales() method
that allows invalidating the resource scales of all actors. With the new
stage-views API that's going to be added to ClutterActor, we also need a
method to invalidate the stage-views lists of actors in case the stage
views are rebuilt and fortunately we can re-use the infrastructure for
invalidating resource scales for that.
So since resource scales depend on the stage views an actor is on,
rename clutter_stage_update_resource_scales() and related methods to
clutter_stage_clear_stage_views(), which also covers resource scales.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1196
Using XDG_CONFIG_HOME allows users to place their keyboard configuration into
their home directory and have them loaded automatically.
libxkbcommon now defaults to XDG_CONFIG_HOME/xkb/ first, see
https://github.com/xkbcommon/libxkbcommon/pull/117
However - libxkbcommon uses secure_getenv() to obtain XDG_CONFIG_HOME and thus
fails to load this for the mutter context which has cap_sys_nice.
We need to manually add that search path as lookup path.
As we can only append paths to libxkbcommon's context, we need to start with
an empty search path set, add our custom path, then append the default search
paths.
The net effect is nil where a user doesn't have XDG_CONFIG_HOME/xkb/.
https://gitlab.gnome.org/GNOME/mutter/merge_requests/936
