[gnome-shell] dnd: Avoid division by zero, etc for zero-size actors

[Alexander Larsson <alexl src gnome org>]

commit 72120bb87fe34895cd52e3e17eb7f020ab6950a7
Author: Alexander Larsson <alexl redhat com>
Date:   Fri Mar 4 14:21:17 2011 +0100

    dnd: Avoid division by zero, etc for zero-size actors
    
    When rescaling due to a possible parent actor resize avoid problems
    if the parent width is zero.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=643786

 js/ui/dnd.js |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)
---
diff --git a/js/ui/dnd.js b/js/ui/dnd.js
index a755057..8751556 100644
--- a/js/ui/dnd.js
+++ b/js/ui/dnd.js
@@ -480,7 +480,9 @@ _Draggable.prototype = {
             let [parentX, parentY] = this._dragOrigParent.get_transformed_position();
             let [parentWidth, parentHeight] = this._dragOrigParent.get_size();
             let [parentScaledWidth, parentScaledHeight] = this._dragOrigParent.get_transformed_size();
-            let parentScale = parentScaledWidth / parentWidth;
+            let parentScale = 1.0;
+            if (parentWidth != 0)
+                parentScale = parentScaledWidth / parentWidth;
 
             x = parentX + parentScale * this._dragOrigX;
             y = parentY + parentScale * this._dragOrigY;