[mutter] clutter: Also pick on BUTTON_PRESS events

[Marge Bot <marge-bot src gnome org>]

commit 4d54c3c556d753c0b981406937948895141dc1d4
Author: Jonas Dreßler <verdre v0yd nl>
Date:   Mon Mar 1 15:51:51 2021 +0100

    clutter: Also pick on BUTTON_PRESS events
    
    In an x11 session, we don't receive motion events from X when the
    pointer is above a window. Since commit 734a1859 we only do picking on
    motion events though, which means when clicking the mouse to focus a
    window, we don't repick and might still think the pointer is hovering
    above another window or actor, ending up not focussing the window.
    
    Fix this by always repicking on BUTTON_PRESS events. While this is not
    necessary in the wayland session, button presses happen rarely compared
    to motion events, so it's not a performance regression to do it in
    Wayland sessions, too.
    
    Fixes https://gitlab.gnome.org/GNOME/mutter/-/issues/1660
    
    Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1752>

 clutter/clutter/clutter-main.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)
---
diff --git a/clutter/clutter/clutter-main.c b/clutter/clutter/clutter-main.c
index 282312bc0b..4b7b141e77 100644
--- a/clutter/clutter/clutter-main.c
+++ b/clutter/clutter/clutter-main.c
@@ -1701,7 +1701,12 @@ _clutter_process_event_details (ClutterActor        *stage,
                   break;
                 }
 
-              if (event->type == CLUTTER_MOTION)
+              /* We need to repick on both motion and button press events, the
+               * latter is only needed for X11 (there the device actor might be
+               * stale because we don't always receive motion events).
+               */
+              if (event->type == CLUTTER_BUTTON_PRESS ||
+                  event->type == CLUTTER_MOTION)
                 {
                   event->any.source =
                     update_device_for_event (CLUTTER_STAGE (stage), event, TRUE);