myDash: drag correctly when height is expanded.

Correctly drag icons when the height of the dash is expanded. Compute the total
height of the icons by summing their heights instead of using the container
height.

Conflicts:
	myDash.js

myDash.js

@@ -658,7 +658,10 @@ const myDash = new Lang.Class({
 
         let children = this._box.get_children();
         let numChildren = children.length;
-        let boxHeight = this._box.height;
+        let boxHeight = 0;
+        for (let i = 0; i < numChildren; i++) {
+            boxHeight += children[i].height;
+        }
 
         // Keep the placeholder out of the index calculation; assuming that
         // the remove target has the same size as "normal" items, we don't
@@ -669,9 +672,11 @@ const myDash = new Lang.Class({
         }
 
         let pos;
-        if (!this._emptyDropTarget)
+        if (!this._emptyDropTarget){
             pos = Math.floor(y * numChildren / boxHeight);
-        else
+            if (pos >  numChildren)
+                pos = numChildren;
+        } else
             pos = 0; // always insert at the top when dash is empty
 
         if (pos != this._dragPlaceholderPos && pos <= numFavorites && this._animatingPlaceholdersCount == 0) {