[PATCH] xwayland: Clear pending cursor frame callbacks on pointer enter

[Rui Matos]

The last cursor frame we commited before the pointer left one of our
surfaces might not have been shown. In that case we'll have a cursor
surface frame callback pending which we need to clear so that we can
continue submitting new cursor frames.

Signed-off-by: Rui Matos <tiagomatos at gmail.com>
---

On Wed, Feb 3, 2016 at 9:30 AM, Pekka Paalanen <ppaalanen at gmail.com> wrote:
> Xwayland commits a wl_buffer to a cursor wl_surface with a frame
> callback, and the frame callback may never be emitted by the
> compositor, right?
>
> Is Xwayland waiting for any previous frame callback to be signalled
> before it commits a buffer or re-sets the cursor role on the
> wl_surface? Even if the commit and re-set is caused by wl_pointer.enter?
>
> Would it be a better fix to destroy any pending frame callback and
> commit and re-set the role unconditionally on wl_pointer.enter?

Yes, this seems like the proper fix indeed. Thanks,

Rui

 hw/xwayland/xwayland-input.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/hw/xwayland/xwayland-input.c b/hw/xwayland/xwayland-input.c
index 61ca70b..f9e3255 100644
--- a/hw/xwayland/xwayland-input.c
+++ b/hw/xwayland/xwayland-input.c
@@ -267,6 +267,16 @@ pointer_handle_enter(void *data, struct wl_pointer *pointer,
     for (i = 0; i < dev->button->numButtons; i++)
         if (BitIsOn(dev->button->down, i))
             QueuePointerEvents(dev, ButtonRelease, i, 0, &mask);
+
+    /* The last cursor frame we commited before the pointer left one
+     * of our surfaces might not have been shown. In that case we'll
+     * have a cursor surface frame callback pending which we need to
+     * clear so that we can continue submitting new cursor frames. */
+    if (xwl_seat->cursor_frame_cb) {
+        wl_callback_destroy(xwl_seat->cursor_frame_cb);
+        xwl_seat->cursor_frame_cb = NULL;
+        xwl_seat_set_cursor(xwl_seat);
+    }
 }
 
 static void
-- 
2.5.0