title: Subversion option to display results of update without actually updating
body: <p>The perforce command:</p>
  
  <p><code>p4 sync -n</code></p>
  
  <p>will display the results of the sync (update in subversion) without actually performing the sync.</p>
  
  <p>I've been looking in the svn help pages and googling around for a tag/command in subversion that will do the same but have yet to find one.  I was thinking there may be a tag for svn update that would accomplish this.  Is there one?</p>