title: Indicate that new file in subversion is actually a copy
body: <p>Say that I have a file in my Subversion repository called <code>MyClass.cs</code>.  Over time, <code>MyClass</code> has grown to the point that I want to split it into two separate files, but I need to preserve the history of each line of code.</p>
  
  <p>One option available to me is to do a SVN copy to <code>MyClass2.cs</code>, and then delete half the code from one file and half from the other.  This works reasonably well, provided I delete the right things from each.</p>
  
  <p>However, what can I do if I've done all the work to separate the files, and then realized (before committing) that I <em>didn't</em> do the copy.  <strong>Is there a way to indicate that "this existing new file" is a copy of "this other known file"?</strong></p>
  
  <p>I'm using TortoiseSVN, so a mechinism in that would be ideal, but I'm comfortable with the command line if neccesary.</p>
  
  <p><a href="https://stackoverflow.com/questions/5524083/is-it-possible-to-retroactively-add-history-that-would-have-been-there-if-an-svn">This other question</a> addresses retroactively adding the change far in the past, but I'm just looking for a pre-commit answer.</p>