Commit Graph

25732 Commits

Author SHA1 Message Date
Jonas Ådahl
73cb96ddb9 clutter: Remove 'ClutterAlpha'
It was some kind of deprecated interpolation mechanism used in
ClutterAnimation. We're not using it, and have non-deprecated
replacement functionality, so lets drop it.

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1192
2020-05-07 20:04:07 +00:00
Jonas Ådahl
1cb59f44ab clutter/layout-manager: Remove unused animation API
One less unused animation API to care about.

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1192
2020-05-07 20:04:07 +00:00
Jonas Ådahl
a55a286b15 clutter: Remove deprecated 'ClutterState'
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1192
2020-05-07 20:04:07 +00:00
Ting-Wei Lan
18e7b814f2 tests/wayland: Don't test file sealing on the fallback case
When memfd_create isn't used, the file isn't sealed. Therefore, we
should skip test_readonly_seals on the fallback case. This fixes
compilation error on FreeBSD 12, which does not support memfd_create.

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1229
2020-05-07 19:39:13 +00:00
Carlos Garnacho
e073076119 backends/native: Unset the correct button codes when a virtual device is destroyed
We were iterating through evcodes, but using API that expects Clutter button
numbers. Instead of transforming those to Clutter numbers to have those translated
back, use the inner seat API that already takes evcodes.

Fixes stuck buttons keys after a virtual device is destroyed while those are
pressed.

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1239
2020-05-07 17:01:05 +00:00
Olivier Fourdan
5d58156134 wayland/keyboard: Chain finalize up to the parent class
Finalize the parent class of the Wayland keyboard object.

Suggested-by: Marco Trevisan (Treviño) <mail@3v1n0.net>
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1238
2020-05-07 10:27:32 +00:00
Jonas Dreßler
c38fa4fa5c clutter: Remove CLUTTER_ACTOR_IN_REPARENT flag
The CLUTTER_ACTOR_IN_REPARENT and the CLUTTER_IN_REPARENT flag are never
set and the logic for skipping unmap, unrealize and the emission of the
"parent-set" signal during reparents has been solved differently by
leaving out the CHECK_STATE and EMIT_PARENT_SET flags when calling
add_child_internal() and remove_child_internal().

The only place where those REPARENT flags are theoretically still useful
is in the clutter_actor_verify_map_state() debugging function, but that
is never called during reparent anyway, so simply leave the comment
regarding reparent there.

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1228
2020-05-07 09:01:31 +00:00
Sergey Zigachev
5201d77b0b keybindings: Use current monitor for move-to-center
Move to center uses all monitors for calculating work area.

This can lead to an unexpected behaviour on some monitor
configurations resulting in current window being split between
monitors. We should move window to the center of the active display.

Closes https://gitlab.gnome.org/GNOME/mutter/-/issues/1073
2020-05-06 16:03:45 +05:00
Christian Rauch
aedf692e0c backends: move 'input_device' to HAVE_LIBWACOM scope
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1231
2020-05-03 23:35:03 +01:00
Florian Müllner
5dfd86ebe7 Bump version to 3.37.1
Update NEWS.
2020-04-29 18:47:11 +02:00
Jonas Ådahl
9e41f687a0 remote-access-controller: Make it build with -Dremote_desktop=false
It'll be all no-ops, which is fine, since there is nothing to
inhibit/uninhibit.

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1223
2020-04-28 22:00:11 +02:00
Olivier Fourdan
61356caa06 keybindings: Mask out the reserved modifiers mask
When switching layouts, special modifiers bits may be be set for
internal use by Xkb.

As we now ignore a set of modifiers when processing the special
modifiers keys, we ought to also mask out those reserved modifiers
otherwise we would discard the [Super] key after switching layouts
in X11.

Closes: https://gitlab.gnome.org/GNOME/mutter/issues/1144
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1219
2020-04-27 15:51:47 +00:00
Jonas Ådahl
4300f1f91d remote-access-controller: Allow inhibiting remote access
Inhibiting remote access means any current remote access session is
terminated, and no new ones can be created, until remote access is
uninhibited. The inhibitation is ref counted, meaning there can be more
than one inhibitor.

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1212
2020-04-27 14:31:06 +00:00
Laurent Bigonville
d26dc4ae44 compositor: Only include meta-window-actor-wayland.h when building with wayland
https://gitlab.gnome.org/GNOME/mutter/-/issues/1074
2020-04-27 13:28:28 +00:00
Olivier Fourdan
bd45a00fa3 window-actor/x11: Cache the frame bounds
When resizing an X11 window with client side decorations, the shadow is
clipped by the frame bounds so that we don't need to paint the shadow
under the opaque areas covered by the window and its frame.

When the X11 client uses the EMWH synchronization mechanism (like all
gtk-3 based clients), the actual window may not be updated so that the
actual window and it frame may be behind the expected window frame
bounds, which gives the impression of de-synchronized shadows.

To avoid the issue, keep a copy of the frame bounds as a cache and only
update it when the client is not frozen so that the clipping occurs on
the actual content.

Closes: https://gitlab.gnome.org/GNOME/mutter/issues/1178
https://gitlab.gnome.org/GNOME/mutter/merge_requests/1214
2020-04-27 13:04:38 +02:00
Jonas Dreßler
793a9d45e1 clutter/stage-cogl: Fix painting the redraw clip with the damage region
The redraw clip that's painted together with the damage region has to be
copied earlier than we do right now. That's because if
PAINT_DAMAGE_REGION is enabled, buffer age is disabled and thus
use_clipped_redraw is FALSE. That means the redraw_clip is updated and
set to the full view-rect. If we copy the queued_redraw_clip after that,
it's also going to be set to the full view-rect. So copy the redraw clip
a bit earlier to make sure we're actually passing the real redraw clip
to paint_damage_region().

Also keep the queued_redraw_clip around a bit longer so it can actually
be used by paint_damage_region() and isn't freed before that.

While at it, move paint_damage_region() from swap_framebuffer() into
clutter_stage_cogl_redraw_view() so we don't have to pass things to
swap_framebuffer() only for debugging.

Fixes https://gitlab.gnome.org/GNOME/mutter/-/issues/1104

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1208
2020-04-25 16:42:30 +02:00
Christian Kirbach
43295bdcc4 Update German translation
(cherry picked from commit bfe9b333c0)
2020-04-24 22:38:04 +00:00
Florian Müllner
43e12dab7b backend: Remove support for META_DUMMY_MONITORS variable
Forcing a dummy monitor manager is unexpected and has been broken
since commit 315a6f43d.

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1213
2020-04-23 21:31:46 +02:00
Jonas Ådahl
c4535fdf85 screen-cast: Add RecordArea for screen cast arbitrary area
It takes coordinates in stage coordinate space, and will result in
a screen cast stream consisting of that area, but scaled up by the scale
factor of the view that overlaps with the area and has the highest scale
factor.

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1207
2020-04-23 14:45:53 +00:00
Jonas Ådahl
d2c3272eb7 clutter/paint-context: Add 'no-cursors' paint flag
Will be used by the stage to not paint the overlays. We skip all
overlays since overlays are only ever used for pointer cursors when the
hardware cursors cannot or should not be used.

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1207
2020-04-23 14:45:53 +00:00
Jonas Ådahl
90c4b6492f stage: Only invoke paint phase callbacks when painting views
These phase callbacks are not intended to be inovked when something
secondary is painting the stage, such as a screen cast stream, or
similar. Thus, only invoke the callbacks when there is a view associated
with the paint context, which will not be the case for offscreen
painting.

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1207
2020-04-23 14:45:53 +00:00
Jonas Ådahl
b7bf42e778 clutter/stage: Add API to paint to a custom target
Either onto a framebuffer, or into a CPU memory buffer. The latter will
use an former API and then copy the result to CPU memory. The former
allocates an offscreen framebuffer, sets up the relevant framebuffer
matrices and paints part of the stage defined by the passed rectangle.

This will be used by a RecordArea screen cast API. The former to paint
directly onto PipeWire handled dma-buf framebuffers, and the latter for
PipeWire handled shared memory buffers.

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1207
2020-04-23 14:45:53 +00:00
Jonas Ådahl
e849667be6 screen-cast-stream-src: Add getter for stride
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1207
2020-04-23 14:45:53 +00:00
Jonas Ådahl
424016d66c stage: Pass paint context in phase callbacks
If there is a paint context available (i.e. for the phases that are
during the actual stage paint), pass it along the callbacks, so that
the callback implementations can change their operation depending on the
paint context state.

This also means we can get the current view from the paint context,
instead of the temporarily used field in the instance struct.

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1207
2020-04-23 14:45:53 +00:00
Jonas Ådahl
a4f55d4986 clutter/paint-context: Allow passing redraw clip to offscreen paint context
So that we can mark the redraw clip of the part of the stage we're
painting.

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1207
2020-04-23 14:45:53 +00:00
Jonas Ådahl
1b33a5a3a7 clutter/paint-context: Add paint flag
A paint flag affects a paint operation in ways defined by the flags.
Currently no flags are defined, so no semantical changes are defined
yet. Eventually a flag aiming to avoid painting of cursors is going to
be added, so that screen cast streams can decide whether to include a
cursor or not.

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1207
2020-04-23 14:45:53 +00:00
Pekka Paalanen
36111270aa kms-impl/simple: Fix page_flip_data ref leak on fallback
If drmModePageFlip() or custom_page_flip_func fails, process_page_flip() was
forgetting to undo the ref taken for that call. This would leak page_flip_data.

The reference counting works like this:
- when created, ref count is 1
- when calling drmModePageFlip, ref count is increased to 2
- new: if flip failed, ref count is decreased back to 1
- if calling schedule_retry_page_flip(), it takes a ref internally
- if calling mode_set_fallback(), it takes a ref internally
- all return FALSE paths have an explicit unref
- return TRUE path has an explicit unref

This issue was found by code inspection and while debugging an unrelated issue
with debug prints sprinkled around. I am not aware of any end-user visible
issues being fixed by this, as the leak is small and probably very rare.

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1209
2020-04-23 16:30:22 +03:00
Pekka Paalanen
6e0cfd3e55 kms: Make GSource ready by default
When testing a laptop with intel and DisplayLink devices, attempting to set the
DL output as the only active output resulted in GNOME/Wayland freezing. The
main event loop was running fine, but nothing on screen would get updated once
the DL output become the only one. This patch fixes that issue.

DisplayLink USB 3 devices use an out-of-tree kernel DRM driver called EVDI.
EVDI can sometimes fail drmModePageFlip(). For me, the flip fails reliably when
hotplugging the DL dock and when changing display configuration to DL only.
Mutter has a workaround for failing flips, it just calls drmModeSetCrtc() and
that succeeds.

What does not work reliably in the fallback path is Mutter keeping track of the
pageflip. Since drmModePageFlip() failed, there will not be a pageflip event
coming and instead Mutter queues a callback in its stead. When you have more
than one output, some other output repainting will attempt to swap buffers and
calls wait_for_pending_flips() which has the side-effect of dispatching any
queued flip callbacks. With multiple outputs, you don't get stuck (unless they
all fail the exact same way at the same time?). When you have only one output,
it cannot proceed to repaint and buffer swap because the pageflip is not marked
complete yet. Nothing dispatches the flip callback, leading to the freeze.

The flip callback is intended to be an idle callback, implemented with a
GSource. It is supposed to be called as soon as execution returns to the main
event loop. The setup of the GSource is incomplete, so it will never dispatch.

Fix the GSource setup by setting its ready-time to be always in the past. That
gets it dispatched on the next cycle of the main event loop. This is now the
default behavior for all sources created by meta_kms_add_source_in_impl().
Sources that need a delay continue to do that by overriding the ready-time
explicitly.

An alternative solution could have been to implement GSource prepare and check
callbacks returning TRUE. However, since meta_kms_add_source_in_impl() is used
by flip retry code as well, and that code needs a delay through the ready-time,
I was afraid I might break the flip retry code. Hence I decided to use
ready-time instead.

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1209
2020-04-23 16:30:17 +03:00
Carlos Garnacho
5671f0a284 x11: Allow X11 clients to clear the selection
According to the XSetSelectionOwner libX11 documentation:

  [...] If the owner window it has specified in the request is later
  destroyed, the owner of the selection automatically reverts to None,
  but the last-change time is not affected.

This is indeed visible through the selection_timestamp field in
XFixesSelectionNotify events.

Use this to check whether the selection time is recent-ish (thus
likely coming from an explicit XSetSelectionOwner request) and honor
the client intent by setting a "NULL" owner. If the selection time
is too old, it's definitely an indication of the owner client being
closed, the scenario where we do want the clipboard manager to take
over.

This fixes two usecases:
- X11 LibreOffice / WPS clear the selection each time before copying
  its own content. Mutter's clipboard manager would see each of those
  as a hint to take over, competing with the client over selection
  ownership. This would simply no longer happen
- Password managers may want to clear the selection, which would be
  frustrated by our clipboard manager.

There's a slight window of opportunity for the heuristics to fail
though, if a X11 client sets the selection and closes within 50ms, we
would miss the clipboard manager taking over.

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1206
2020-04-21 21:32:53 +00:00
Carlos Garnacho
a7e63bea6c x11: Generalize x11 selection owner checks
Shuffle things so the x11 selection can check the current owner directly,
instead of its type.

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1206
2020-04-21 21:32:53 +00:00
Carlos Garnacho
94b3c334e5 x11: Clear X11 selection source after unsetting owner
The X11 selection source was being preserved after unsetting its
ownership. This is no leak as it would be eventually replaced by
another source, or destroyed on finalize. But it's pointless to
keep it.

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1206
2020-04-21 21:32:53 +00:00
Jonas Dreßler
efb0addb62 tests/wayland: Add a test for meta-anonymous-file
Test the two modes of MetaAnonymousFile, MAPMODE_SHARED and
MAPMODE_PRIVATE and make sure they don't leak data to other FDs when
writing to an FD provided by `meta_anonymous_file_get_fd` even though
the data of both FDs is residing in the same chunk of memory.

We do all the reading tests using mmap instead of read() since using
read() on shared FDs is going to move the read cursor of the fd. That
means using read() once on the shared FD returned by
meta_anonymous_file_get_fd() in MAPMODE_PRIVATE breaks every subsequent
read() call.

Also test the fallback code of MetaAnonymousFile in case `memfd_create`
isn't used for the same issues.

https://gitlab.gnome.org/GNOME/mutter/merge_requests/1012
2020-04-21 17:52:08 +02:00
Jonas Dreßler
988da215c8 wayland/keyboard: Use MetaAnonymousFile to share keymap files
Since protocol version 7 clients must use MAP_PRIVATE to map the keymap
fd, that means we can use memfd_create() to create the fd by using
meta_anonymous_file_open_fd() with META_ANONYMOUS_FILE_MAPMODE_PRIVATE,
for older versions we use META_ANONYMOUS_FILE_MAPMODE_SHARED to be
compatibile with MAP_SHARED.

Pretty much all of this code was written for Weston by Sebastian Wick,
see https://gitlab.freedesktop.org/wayland/weston/merge_requests/240.

Co-authored-by: Sebastian Wick <sebastian@sebastianwick.net>

Fixes https://gitlab.gnome.org/GNOME/gnome-shell/issues/1734

https://gitlab.gnome.org/GNOME/mutter/merge_requests/1012
2020-04-21 17:52:08 +02:00
Jonas Dreßler
551a57ed7f Add read-only anonymous file abstraction MetaAnonymousFile
Add MetaAnonymousFile, an abstraction around anonymous read-only files.
Files can be created by calling meta_anonymous_file_new(), passing the
data of the file. Subsequent calls to meta_anonymous_file_open_fd()
return a fd that's ready to be sent over the socket.

When mapmode is META_ANONYMOUS_FILE_MAPMODE_PRIVATE the fd is only
guaranteed to be mmap-able readonly with MAP_PRIVATE but does not
require duplicating the file for each resource when memfd_create is
available. META_ANONYMOUS_FILE_MAPMODE_SHARED may be used when the
client must be able to map the file with MAP_SHARED but it also means
that the file has to be duplicated even when memfd_create is available.

Pretty much all of this code was written for weston by Sebastian Wick,
see https://gitlab.freedesktop.org/wayland/weston/merge_requests/240.

Co-authored-by: Sebastian Wick <sebastian@sebastianwick.net>

https://gitlab.gnome.org/GNOME/mutter/merge_requests/1012
2020-04-21 17:52:08 +02:00
Carlos Garnacho
b7366b5b53 wayland: Drop unused struct variable
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1193
2020-04-17 00:51:00 +02:00
Carlos Garnacho
5e8d8b9ade wayland: Move the primary data device manager to its own file
Instead of having everything clumped at MetaWaylandDataManager,
split the primary selection to its own struct. This manager is
handled separately from wl_data_device_manager and other selection
managers, so they would be able to interoperate between them, even.

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1193
2020-04-17 00:50:57 +02:00
Carlos Garnacho
4726f3d5d3 wayland: Move primary data offers to their own file
Following the MetaWaylandDataOffer split.

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1193
2020-04-17 00:46:23 +02:00
Carlos Garnacho
91ef7515de wayland: Move MetaWaylandDataOffer to its own file
This is still an openly defined struct, as we will need accessed
by "subclasses". Same principle applies than with the
MetaWaylandDataSource refactor, this is not meant to introduce
functional changes, so just go with it.

On the bright side, the interactions are now clearer, so it could
be made saner in the future.

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1193
2020-04-17 00:46:23 +02:00
Carlos Garnacho
317f6c0910 wayland: Move MetaWaylandDataSourcePrimary to its own file
Following the MetaWaylandDataSource split, this goes next.

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1193
2020-04-17 00:46:23 +02:00
Carlos Garnacho
6a3d521466 wayland: Split MetaWaylandDataSource into a separate file
The split wasn't 100% clean, and some extra private API had to be
added for it (but well, looking at the API, it's already evident
there's a cleanup/streamlining task due). This is meant to be a
refactor with no functional changes, so just go with it.

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1193
2020-04-17 00:46:21 +02:00
Carlos Garnacho
1363246d44 wayland: Rely on MetaSelection::owner-changed for .selection event emission
We already have a signal callback that translates selection ownership changes to
data_device/primary .selection events. Given both will be run when a data source
is being replaced, and this event emission being deleted is kinda short sighted
in that in only knows about Wayland, rely entirely on MetaSelection::owner-changed
emission.

Fixes spurious .selection(null) events being sent when a compositor-local source
takes over the selection without the focus changing (eg. screenshot to clipboard).

Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/1160

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1204
2020-04-16 22:25:00 +00:00
Carlos Garnacho
0b6560fac4 wayland: Do not cancel old data source when setting new selection
This is taken care already by the MetaSelection machinery, by
deactivating the previous selection source when setting a new one.
That works across X11 and internal selection sources. This
only works when replacing one wayland source with another, and
actually results in doubly .cancelled events due to the other
paths.

Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/1177

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1203
2020-04-16 19:27:51 +00:00
Carlos Garnacho
d4c3870286 wayland: Shuffle wl_data_source.cancelled version checks on DnD
We are meant to send a .cancelled event after the drop is performed
in certain situations, but only for version>3 clients. Since this is
all version 3 business, only set the drop_performed flag for v3
clients. This drops the need to perform version checks at the time
of cancelling (which is present for other usecases in v1).

Fixes emission of wl_data_source.cancelled for v1 clients.

Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/1177

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1203
2020-04-16 19:27:51 +00:00
Carlos Garnacho
4bdf9a1e70 core: Cater for reading selection in chunks
For the cases where we read a fixed size from the selection (eg. imposing
limits for the clipboard manager), g_input_stream_read_bytes_async() might
not read up to this given size if the other side is spoonfeeding it content.

Cater for multiple read/write cycles here, until (maximum) transfer size is
reached.

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1198
2020-04-16 16:26:04 +00:00
Carlos Garnacho
1909977a67 x11: Do not trust there is task in error paths
Flushing the X11 selection output stream may happen synchronously or
implicitly, in which case there is not a task to complete. Check there
is actually a task before returning errors. We additionally set the
pipe_error flag, so future operations will fail with an error, albeit
with a more generic message.

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1198
2020-04-16 16:26:04 +00:00
Carlos Garnacho
655a783891 x11: Don't stall on write_async()
If a write_async() comes up while we are flushing on the background,
the task will be queued, but not deemed a reason on itself to keep
flushing (and finish the task) after a property delete event.

To fix this, do not ever queue up write_async tasks (this leaves
priv->pending_task only used for flush(), so the "flush to end"
behavior in the background is consistent). We only start a
background flush if there's reasons to do it, but the tasks are
immediately finished.

All data will still be ensured to be transfered on flush/close,
this makes the caller in this situation still able to reach to it.

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1198
2020-04-16 16:26:04 +00:00
Carlos Garnacho
a4596becc4 x11: Fix iterative INCR property checks
It does not make sense to check for the stream not being closed,
this might happen multiple times during the lifetime of the stream
for a single transfer. We want to notify the INCR transfer just
once.

Check for the explicit conditions that we want, that the remaining
data is bigger than we can transfer at once, and that we are not
yet within the INCR transfer.

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1198
2020-04-16 16:26:04 +00:00
Carlos Garnacho
7015bb3efd x11: Don't exceed transfer size in INCR chunks
The stream automatically flushes after data size exceeds the
size we deem for INCR chunks, but we still try to copy it all.
Actually limit the data we copy, and leave the rest for future
INCR chunks.

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1198
2020-04-16 16:26:04 +00:00
Carlos Garnacho
d2c762cc66 x11: Don't invariably queue a pending delete request
We don't need doing this roundtrip for non-INCR transfers.

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1198
2020-04-16 16:26:04 +00:00
Carlos Garnacho
04d429b743 x11: Finish INCR transfers properly
INCR transfers are mandated to finish with a final 0-size XChangeProperty
roundtrip after the final data chunk. Actually honor this and ensure we
iterate just once more for this.

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1198
2020-04-16 16:26:04 +00:00