fix 2841060: Folders appear to accept drag-and-drop of widgets

Change-Id: I6e408c25d52c8b3a5f64149326df901fce1ce597
diff --git a/src/com/android/launcher2/FolderIcon.java b/src/com/android/launcher2/FolderIcon.java
index a09b6e0..78a9516 100644
--- a/src/com/android/launcher2/FolderIcon.java
+++ b/src/com/android/launcher2/FolderIcon.java
@@ -91,7 +91,9 @@
 
     public void onDragEnter(DragSource source, int x, int y, int xOffset, int yOffset,
             DragView dragView, Object dragInfo) {
-        setCompoundDrawablesWithIntrinsicBounds(null, mOpenIcon, null, null);
+        if (acceptDrop(source, x, y, xOffset, yOffset, dragView, dragInfo)) {
+            setCompoundDrawablesWithIntrinsicBounds(null, mOpenIcon, null, null);
+        }
     }
 
     public void onDragOver(DragSource source, int x, int y, int xOffset, int yOffset,