[gnome-shell] altTab: Set allocation before allocating children

[Florian Müllner <fmuellner src gnome org>]

commit 49d6db34b74752dc11dfff7a51ad4f6ebf8cdf57
Author: Jonas Dreßler <verdre v0yd nl>
Date:   Thu Mar 12 13:37:53 2020 +0100

    altTab: Set allocation before allocating children
    
    Just as with the last commit, we should not break the assumption made by
    Clutter that parents have their allocation set before their children get
    allocated, so fix that here, too.
    
    In this case we have to fix it by chaining up to the parent vfunc
    override and updating the allocation once more before allocating the
    `this._label` child.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/1615

 js/ui/altTab.js | 26 +++++++++++++-------------
 1 file changed, 13 insertions(+), 13 deletions(-)
---
diff --git a/js/ui/altTab.js b/js/ui/altTab.js
index 94b80f7920..1c35a001e9 100644
--- a/js/ui/altTab.js
+++ b/js/ui/altTab.js
@@ -1060,25 +1060,25 @@ class WindowSwitcher extends SwitcherPopup.SwitcherList {
     vfunc_allocate(box, flags) {
         let themeNode = this.get_theme_node();
         let contentBox = themeNode.get_content_box(box);
+        const labelHeight = this._label.height;
+        const totalLabelHeight =
+            labelHeight + themeNode.get_padding(St.Side.BOTTOM);
 
-        let childBox = new Clutter.ActorBox();
-        childBox.x1 = contentBox.x1;
-        childBox.x2 = contentBox.x2;
-        childBox.y2 = contentBox.y2;
-        childBox.y1 = childBox.y2 - this._label.height;
-        this._label.allocate(childBox, flags);
-
-        let totalLabelHeight = this._label.height + themeNode.get_padding(St.Side.BOTTOM);
-        childBox.x1 = box.x1;
-        childBox.x2 = box.x2;
-        childBox.y1 = box.y1;
-        childBox.y2 = box.y2 - totalLabelHeight;
-        super.vfunc_allocate(childBox, flags);
+        box.y2 -= totalLabelHeight;
+        super.vfunc_allocate(box, flags);
 
         // Hooking up the parent vfunc will call this.set_allocation() with
         // the height without the label height, so call it again with the
         // correct size here.
+        box.y2 += totalLabelHeight;
         this.set_allocation(box, flags);
+
+        const childBox = new Clutter.ActorBox();
+        childBox.x1 = contentBox.x1;
+        childBox.x2 = contentBox.x2;
+        childBox.y2 = contentBox.y2;
+        childBox.y1 = childBox.y2 - labelHeight;
+        this._label.allocate(childBox, flags);
     }
 
     highlight(index, justOutline) {