[mutter] clutter/text: Make update_cursor_location() operate in stage coordinates

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

commit ebf9f18080c9c6b2df4329191391d007b0ea8cf2
Author: Daniel van Vugt <daniel van vugt canonical com>
Date:   Thu Nov 19 18:15:34 2020 +0800

    clutter/text: Make update_cursor_location() operate in stage coordinates
    
    Until now we would `clutter_input_focus_set_cursor_location` with
    cursor-rectangle-in-physical-pixels + actor-location-in-stage-coordinates.
    But those use different scaling factors so it only got the right answer
    when the framebuffer scale was 1.0.
    
    This directly determines the geometry of the invisible dummy cursor in
    gnome-shell ibusCandidatePopup.js:
    
    ```
      panelService.connect('set-cursor-location', (ps, x, y, w, h) => {
          this._setDummyCursorGeometry(x, y, w, h);
      });
    ```
    
    And because it's invisible it wasn't obvious that it was wrong until you
    enable `CLUTTER_PAINT=damage-region` and you can see its ghost at the wrong
    offset and scale.
    
    So now we `clutter_input_focus_set_cursor_location` using purely unscaled
    stage coordinates. And `CLUTTER_PAINT=damage-region` shows that
    gnome-shell's `_dummyCursor` is placed precisely over the visible cursor.
    
    Fixes: https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/3399
    and probably other IBus issues that arise when using framebuffer scaling.
    
    Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1576>

 clutter/clutter/clutter-text.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/clutter/clutter/clutter-text.c b/clutter/clutter/clutter-text.c
index 98fa0772a8..159fa330e9 100644
--- a/clutter/clutter/clutter-text.c
+++ b/clutter/clutter/clutter-text.c
@@ -1307,7 +1307,7 @@ update_cursor_location (ClutterText *self)
   if (!priv->editable)
     return;
 
-  rect = priv->cursor_rect;
+  clutter_text_get_cursor_rect (self, &rect);
   clutter_actor_get_transformed_position (CLUTTER_ACTOR (self), &x, &y);
   graphene_rect_offset (&rect, x, y);
   clutter_input_focus_set_cursor_location (priv->input_focus, &rect);