tree 6121413bacc7b0d7acb69593ff9703fb7e168e3a
parent d86ff50b82ed5d52d51e18da494088cdbf0b1fc1
author Dave Borowitz <dborowitz@google.com> 1398796345 -0700
committer Dave Borowitz <dborowitz@google.com> 1398807329 -0700

Fix NPE in DiffServlet for missing path

The isFile method added by Ib11706aa did not handle the case where
TreeWalk.forPath returns null, as it does for a missing path.

This affected any diff URL with a non-empty, nonexistent path, e.g.:
  /project/+diff/master/notfound

Change-Id: I5c99be0cbdc99174c4a21b4deae6ac5b5bbd13fd