Created attachment 344334 [details] [review]
backends/x11/nested: Don't interfere with host XKB state

Don't lock the XKB layout group when running nested, as that will
interfere with the host X11 server state, as the X11 connection in the
backend is the one of the host.

This fixes an issue where mutter incorrectly changed the keyboard
layout of Xwayland clients under Wayland. See
https://bugs.freedesktop.org/show_bug.cgi?id=93237 for details.

Review of attachment 344334 [details] [review]:

Heh, nested... so, I guess apply_keymap() should also be skipped in nested mode

Created attachment 344835 [details] [review]
backends/x11: Split up X11 backend into Cm and Nested

Split up the X11 backend into two parts, one for running as a
Compositing Manager, and one for running as a nested Wayland
compositor.

----

I went with this approach. Could as well just add more and more if (mode) blocks here and there, but thought a real backend split might be better.

Created attachment 344836 [details] [review]
backends/x11: Only apply keymap when not running nested

Review of attachment 344835 [details] [review]:

::: src/backends/x11/meta-backend-x11.c
@@ +103,3 @@
        * and never under nested, as under nested all backend events
        * should be reported with respect to the stage window. */
+      g_assert (META_IS_BACKEND_X11_CM (x11));

this could be a vfunc as well and we'd avoid having the parent class know about the child class

::: src/backends/x11/nested/meta-backend-x11-nested.c
@@ +117,3 @@
+      if (event->xfocus.window == xwin)
+        {
+#ifdef HAVE_WAYLAND

might as well put all but the return sentence inside the #ifdef

::: src/core/main.c
@@ +427,3 @@
+  else
+#endif /* HAVE_WAYLAND */
+    *backend_gtype = META_TYPE_BACKEND_X11_CM;

if opt_nested this should still be _NESTED I think. the logic here is getting p complex

Review of attachment 344836 [details] [review]:

::: src/backends/x11/meta-backend-x11.c
@@ -35,2 @@
 #include <X11/extensions/sync.h>
 #include <X11/XKBlib.h>

I believe XKBlib.h isn't needed here anymore

::: src/backends/x11/nested/meta-backend-x11-nested.c
@@ +143,3 @@
+                                    const char  *options)
+{
+  g_warning ("Tried to set keymap when running nested.\n");

not warning worthy IMO

@@ +161,3 @@
   backend_class->update_screen_size = meta_backend_x11_nested_update_screen_size;
   backend_class->select_stage_events = meta_backend_x11_nested_select_stage_events;
+  backend_class->set_keymap = meta_backend_x11_nested_set_keymap;

no lock_layout_group vfunc?

Created attachment 345080 [details] [review]
backends/x11: Split up X11 backend into Cm and Nested

Split up the X11 backend into two parts, one for running as a
Compositing Manager, and one for running as a nested Wayland
compositor.

This commit also cleans up the compositor configuration calculation,
attempting to make it more approachable.

Created attachment 345081 [details] [review]
backends/x11: Only apply keymap when not running nested

Review of attachment 345081 [details] [review]:

looks fine

Review of attachment 345080 [details] [review]:

looks good

::: src/backends/x11/nested/meta-backend-x11-nested.c
@@ +26,3 @@
+#include "backends/x11/nested/meta-cursor-renderer-x11-nested.h"
+
+#include "wayland/meta-wayland.h"

#ifdef HAVE_WAYLAND

::: src/core/main.c
@@ +402,3 @@
+/*
+ * Determine the compositor configuration, i.e. whether to run as a Wayland
+ * compositor or an X11 window manager, as well as what backend to use.

nitpick: s/or an X11 window manager// - there's no way we are not an X11 window manager, but we may or may not be a wayland compositor

Attachment 345080 [details] pushed as 6d64123 - backends/x11: Split up X11 backend into Cm and Nested
Attachment 345081 [details] pushed as bd2ca79 - backends/x11: Only apply keymap when not running nested