xwayland: Add a -nokeymap option

By default, Xwayland (as any Wayland client) uses the keymap set by the
Wayland compositor using the standard Wayland protocol.

There are some specific uses cases where a user would want to let the
X11 clients control the keymap. However, the Wayland compositor may
(re)send the keymap at any time, overriding whatever change was made
using the X11 mechanisms.

Add a new "-nokeymap" option to Xwayland to instruct Xwayland to simply
ignore the standard Wayland mechanism to set the keymap, hence leaving
the control entirely to the X11 clients.

Signed-off-by: Olivier Fourdan <ofourdan@redhat.com>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>

hw/xwayland/man/Xwayland.man

@@ -124,6 +124,15 @@ support touch input.
 Force additional non-native modes to be exposed when viewporter is not
 supported by the Wayland compositor.
 .TP 8
+.B \-nokeymap
+Instructs \fIXwayland\fP to ignore the keymap set by the Wayland compositor.
+
+By default, \fIXwayland\fP (as any Wayland client) uses the keymap set by the
+Wayland compositor using the standard Wayland protocol.
+
+This option is meant for some specific use cases where it may be desirable to
+let the X11 clients control the keymap used in Xwayland, ignoring the keymap
+specified by the Wayland compositor.
 .B \-output \fIname\fP
 Specifies on which output \fIXwayland\fP fullscreen rootful should be placed.
 The name must match the name of an existing Wayland output (output names can

hw/xwayland/xwayland-input.c

@@ -1113,10 +1113,14 @@ keyboard_handle_keymap(void *data, struct wl_keyboard *keyboard,
                        uint32_t format, int fd, uint32_t size)
 {
     struct xwl_seat *xwl_seat = data;
+    struct xwl_screen *xwl_screen = xwl_seat->xwl_screen;
     DeviceIntPtr master;
     XkbDescPtr xkb;
     XkbChangesRec changes = { 0 };
 
+    if (xwl_screen->nokeymap)
+        return;
+
     if (xwl_seat->keymap)
         munmap(xwl_seat->keymap, xwl_seat->keymap_size);
 

hw/xwayland/xwayland-screen.c

@@ -869,6 +869,9 @@ xwl_screen_init(ScreenPtr pScreen, int argc, char **argv)
             ErrorF("This build does not have XDG portal support\n");
 #endif
         }
+        else if (strcmp(argv[i], "-nokeymap") == 0) {
+            xwl_screen->nokeymap = 1;
+        }
     }
 
     if (!xwl_screen->rootless) {

hw/xwayland/xwayland-screen.h

@@ -68,6 +68,7 @@ struct xwl_screen {
     int has_grab;
     int decorate;
     int enable_ei_portal;
+    int nokeymap;
 
     CreateScreenResourcesProcPtr CreateScreenResources;
     CloseScreenProcPtr CloseScreen;

hw/xwayland/xwayland.c

@@ -94,6 +94,7 @@ ddxUseMsg(void)
     ErrorF("-fullscreen            run fullscreen when rootful\n");
     ErrorF("-geometry WxH          set Xwayland window size when rootful\n");
     ErrorF("-host-grab             disable host keyboard shortcuts when rootful\n");
+    ErrorF("-nokeymap              ignore keymap from the Wayland compositor\n");
     ErrorF("-output                specify which output to use for fullscreen when rootful\n");
     ErrorF("-wm fd                 create X client for wm on given fd\n");
     ErrorF("-initfd fd             add given fd as a listen socket for initialization clients\n");
@@ -267,6 +268,9 @@ ddxProcessArgument(int argc, char *argv[], int i)
         CHECK_FOR_REQUIRED_ARGUMENTS(1);
         return 2;
     }
+    else if (strcmp(argv[i], "-nokeymap") == 0) {
+        return 1;
+    }
 
     return 0;
 }