title: SVN reverse merge?
body: <p>My SVN repository was perfect at revision 497. I performed several bad commits, so that now it is at revision HEAD. I see that to rollback you should use a command like this:</p>
  
  <pre><code>svn merge -r HEAD:497 .
  </code></pre>
  
  <p>while in the working directory (and the working directory is at the HEAD revision). But is that the right command? Or do I use HEAD:498? or 496? I already ran that command and the current revision doesn't appear to be the same as 497, because when I update -r 497 (or when I have a 497 working copy and I update -r HEAD), a lot of file updates occur.</p>
  
  <p>Do I have some sort of fencepost problem, where HEAD:497 actually reverts to 496, or something? Or is it that when I update, SVN goes back through each revision, despite the fact that the HEAD and 497 are identical?</p>
  
  <p><strong>Edit:</strong></p>
  
  <p>Just to clarify, as I said earlier when I update between 497 and my merged HEAD, I see a lot of file changes take place. I thought that if 497 and HEAD were identical, it would detect that, and no file changes would occur; it would simply say "Updated to revision 497." So is my command wrong, or is this thinking wrong? (and if so, why?)</p>