workspace: Force creating new layout when there's no allocation yet

Commit ba23279f1fd3820fb81570b1b4a03048e5a7a3bc was aimed at fixing a
bug where the layout is frozen so early that we don't have an existing
one to re-use, because no allocation cycle happened yet. It tried to fix
that by forcing the creation of a layout when needsLayout === true,
this turned out to be a bit too much, as it also forced creating a new
layout when the layout was frozen after closing a window (which would
set needsLayout to true).

To fix this regression and still avoid reintroducing the bug the
previous commit fixed, tighten the check a bit and only force creating
the new layout when there's no allocation yet. This makes freezing the
layout after closing a window work again.

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/2236>

diff --git a/js/ui/workspace.js b/js/ui/workspace.js
index ebf3d9ba38c4fc2e0386262c3e68ad64efd7dde1..60e0d44a8450808f13b205752be40101d8b757dd 100644 (file)
--- a/js/ui/workspace.js
+++ b/js/ui/workspace.js
@@ -628,7 +628,6 @@ var WorkspaceLayout = GObject.registerClass({
         const [containerWidth, containerHeight] = containerBox.get_size();
         const containerAllocationChanged =
             this._lastBox === null || !this._lastBox.equal(containerBox);
-        this._lastBox = containerBox.copy();
 
         // If the containers size changed, we can no longer keep around
         // the old windowSlots, so we must unfreeze the layout.
@@ -665,7 +664,7 @@ var WorkspaceLayout = GObject.registerClass({
         }
 
         let layoutChanged = false;
-        if (!this._layoutFrozen || this._needsLayout) {
+        if (!this._layoutFrozen || !this._lastBox) {
             if (this._needsLayout) {
                 this._layout = this._createBestLayout(this._workarea);
                 this._needsLayout = false;
@@ -765,6 +764,8 @@ var WorkspaceLayout = GObject.registerClass({
                 child.allocate(childBox);
             }
         }
+
+        this._lastBox = containerBox.copy();
     }
 
     _syncOverlay(preview) {