dnd: Prevent dividing by zero when calculating the scale factor

This ensures that we snap back to the correct size when the
source actor has been scaled to 0.

https://bugzilla.gnome.org/show_bug.cgi?id=787901

diff --git a/js/ui/dnd.js b/js/ui/dnd.js
index 64c1eb51bac2219cfebfead8b5c384cf6b14fe84..a64915bc82997de1542a737940f5cd512f249fab 100644 (file)
--- a/js/ui/dnd.js
+++ b/js/ui/dnd.js
@@ -531,7 +531,7 @@ var _Draggable = new Lang.Class({
             // Snap the clone back to its source
             [x, y] = this._dragActorSource.get_transformed_position();
             let [sourceScaledWidth, sourceScaledHeight] = this._dragActorSource.get_transformed_size();
-            scale = this._dragActor.width / sourceScaledWidth;
+            scale = sourceScaledWidth ? this._dragActor.width / sourceScaledWidth : 0;
         } else if (this._dragOrigParent) {
             // Snap the actor back to its original position within
             // its parent, adjusting for the fact that the parent