[PATCH] xwayland: Only disable/enable devices on capabilities change

[Carlos Garnacho]

Anytime a capability is first reported, the device is created, but after
that, it is only disabled/enabled.

This is a closer behavior to what Xorg does on VT switch, at the expense
of maybe leaving a dangling "physical" device if a capability goes for good.
Otherwise, any DeviceIntPtr (re)created after server initialization will be
left floating, and bad things happen when the wayland enter event handler
tries to update cursor position based on a floating device.

Signed-off-by: Carlos Garnacho <carlosg at gnome.org>
---
 hw/xwayland/xwayland-input.c | 42 +++++++++++++++++++++++++++---------------
 1 file changed, 27 insertions(+), 15 deletions(-)

diff --git a/hw/xwayland/xwayland-input.c b/hw/xwayland/xwayland-input.c
index 990cb82..cc5f7df 100644
--- a/hw/xwayland/xwayland-input.c
+++ b/hw/xwayland/xwayland-input.c
@@ -491,31 +491,43 @@ seat_handle_capabilities(void *data, struct wl_seat *seat,
 {
     struct xwl_seat *xwl_seat = data;
 
-    if (caps & WL_SEAT_CAPABILITY_POINTER && xwl_seat->pointer == NULL) {
+    if (caps & WL_SEAT_CAPABILITY_POINTER && xwl_seat->wl_pointer == NULL) {
         xwl_seat->wl_pointer = wl_seat_get_pointer(seat);
         wl_pointer_add_listener(xwl_seat->wl_pointer,
                                 &pointer_listener, xwl_seat);
-        xwl_seat_set_cursor(xwl_seat);
-        xwl_seat->pointer =
-            add_device(xwl_seat, "xwayland-pointer", xwl_pointer_proc);
-    }
-    else if (!(caps & WL_SEAT_CAPABILITY_POINTER) && xwl_seat->pointer) {
+
+        if (xwl_seat->pointer)
+            EnableDevice(xwl_seat->pointer, TRUE);
+        else {
+            xwl_seat_set_cursor(xwl_seat);
+            xwl_seat->pointer =
+                add_device(xwl_seat, "xwayland-pointer", xwl_pointer_proc);
+        }
+    } else if (!(caps & WL_SEAT_CAPABILITY_POINTER) && xwl_seat->wl_pointer) {
         wl_pointer_release(xwl_seat->wl_pointer);
-        RemoveDevice(xwl_seat->pointer, FALSE);
-        xwl_seat->pointer = NULL;
+        xwl_seat->wl_pointer = NULL;
+
+        if (xwl_seat->pointer)
+            DisableDevice(xwl_seat->pointer, TRUE);
     }
 
-    if (caps & WL_SEAT_CAPABILITY_KEYBOARD && xwl_seat->keyboard == NULL) {
+    if (caps & WL_SEAT_CAPABILITY_KEYBOARD && xwl_seat->wl_keyboard == NULL) {
         xwl_seat->wl_keyboard = wl_seat_get_keyboard(seat);
         wl_keyboard_add_listener(xwl_seat->wl_keyboard,
                                  &keyboard_listener, xwl_seat);
-        xwl_seat->keyboard =
-            add_device(xwl_seat, "xwayland-keyboard", xwl_keyboard_proc);
-    }
-    else if (!(caps & WL_SEAT_CAPABILITY_KEYBOARD) && xwl_seat->keyboard) {
+
+        if (xwl_seat->keyboard)
+            EnableDevice(xwl_seat->keyboard, TRUE);
+        else {
+            xwl_seat->keyboard =
+                add_device(xwl_seat, "xwayland-keyboard", xwl_keyboard_proc);
+        }
+    } else if (!(caps & WL_SEAT_CAPABILITY_KEYBOARD) && xwl_seat->wl_keyboard) {
         wl_keyboard_release(xwl_seat->wl_keyboard);
-        RemoveDevice(xwl_seat->keyboard, FALSE);
-        xwl_seat->keyboard = NULL;
+        xwl_seat->wl_keyboard = NULL;
+
+        if (xwl_seat->keyboard)
+            DisableDevice(xwl_seat->keyboard, TRUE);
     }
 
     xwl_seat->xwl_screen->expecting_event--;
-- 
2.0.0