title: svn : how to branch a subdirectory and then later its parent directories
body: <p>I have branched a subdirectory using:</p>
  
  <pre><code>svn cp --parents trunk/path/to/dir branches/path/to/
  </code></pre>
  
  <p>After committing this subdirectory, I later would like to branch source code from a parent directory using:</p>
  
  <pre><code>svn cp --parents trunk/path/to branches/path/
  </code></pre>
  
  <p>However, this returns <code>svn: E150002: Path 'branches/path/to/dir' already exists</code>.  </p>
  
  <pre><code>svn cp --parents looks like it internally calls svn mkdir.  
  </code></pre>
  
  <p>In my case, I often don't know if I'll need the parent directory files in the branch until later on.  I could branch all parent directories first, but this could bloat my branch.  </p>
  
  <p>What is the correct way to do this while preserving the same directory structure as the source location (e.g., trunk)? &nbsp;</p>