Add invalid id check to isValidParent

 Bug: 3512786

Change-Id: I8f16038e230a24bcc50e4cc75d24f413d0166844
diff --git a/src/com/android/browser/provider/BrowserProvider2.java b/src/com/android/browser/provider/BrowserProvider2.java
index c6b1bc7..305c794 100644
--- a/src/com/android/browser/provider/BrowserProvider2.java
+++ b/src/com/android/browser/provider/BrowserProvider2.java
@@ -1236,6 +1236,9 @@
 
     private boolean isValidParent(String accountType, String accountName,
             long parentId) {
+        if (parentId <= 0) {
+            return false;
+        }
         Uri uri = ContentUris.withAppendedId(Bookmarks.CONTENT_URI, parentId);
         Cursor c = query(uri,
                 new String[] { Bookmarks.ACCOUNT_NAME, Bookmarks.ACCOUNT_TYPE },