From: Jonas Dreßler <verdre@v0yd.nl>
Date: Fri, 19 Jun 2020 08:10:21 +0000 (+0200)
Subject: windowPreview: Fix a division by zero
X-Git-Tag: archive/raspbian/50.5-1+rpi1~1^2~684^2^2~215
X-Git-Url: https://dgit.raspbian.org/%22http://www.example.com/cgi/%22/%22http:/www.example.com/cgi/%22?a=commitdiff_plain;h=87e4bf52b7c067c6af5dad00b61b43e65289a627;p=gnome-shell.git

windowPreview: Fix a division by zero

When the bounding box size is 0 during allocation (which happens right
after creating a window for example), we're doing a division by zero and
end up with a NaN scale. This ends up making the childBox NaN, which
triggers an error in Clutters allocation machinery.

So fix that and fall back to a scale of 1 in case the bounding box is
empty.

https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1320
---

diff --git a/js/ui/windowPreview.js b/js/ui/windowPreview.js
index 842a4c515..b7fc5efa5 100644
--- a/js/ui/windowPreview.js
+++ b/js/ui/windowPreview.js
@@ -67,8 +67,12 @@ var WindowPreviewLayout = GObject.registerClass({
     vfunc_allocate(container, box) {
         // If the scale isn't 1, we weren't allocated our preferred size
         // and have to scale the children allocations accordingly.
-        const scaleX = box.get_width() / this._boundingBox.get_width();
-        const scaleY = box.get_height() / this._boundingBox.get_height();
+        const scaleX = this._boundingBox.get_width() > 0
+            ? box.get_width() / this._boundingBox.get_width()
+            : 1;
+        const scaleY = this._boundingBox.get_height() > 0
+            ? box.get_height() / this._boundingBox.get_height()
+            : 1;
 
         const childBox = new Clutter.ActorBox();