authPrompt: Fix spinner alignment

We want the spinner to be centered with regard to the entry, but
constraining the height breaks that:

 1. clutter_actor_allocate() is called with the available size
 2. clutter_actor_update_constraints() then adjusts that according
    to the constraints
 3. clutter_actor_adjust_allocation() applies the margin/expand/align
    properties.

The issue there is that 2. reduces the allocation to the desired size,
so there is no more extra space to distribute in 3.

We can fix this by either constraining everything (and rely on the
cancel button's alignment) or limit the constraint to the width. The
latter seems more appropriate, given that the constraint is only used
to center the entry horizontally.

https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/2628

diff --git a/js/gdm/authPrompt.js b/js/gdm/authPrompt.js
index 3434de0cf01b8cdf76ea8a7d439efe56ab72a1fa..c26b1bcad5cfef9b6a0f4cc0ab9d9ca1422bc446 100644 (file)
--- a/js/gdm/authPrompt.js
+++ b/js/gdm/authPrompt.js
@@ -184,7 +184,7 @@ var AuthPrompt = GObject.registerClass({
         });
         this._defaultButtonWell.add_constraint(new Clutter.BindConstraint({
             source: this.cancelButton,
-            coordinate: Clutter.BindCoordinate.SIZE,
+            coordinate: Clutter.BindCoordinate.WIDTH,
         }));
         this._mainBox.add_child(this._defaultButtonWell);