title: How can I create a patch that spans commits using Sourcetree?
body: <p>I observe that when I "Create a patch", the dialog creates the patch that is "to" the commit I selected "from" it's predecessor.</p>
  
  <p>In the dialog, I can tantalisingly select two separate commits and the diff panel shows the diffs that are between those two - that's the patch that I want.</p>
  
  <p>But when I press "OK", I still get the single commit patch.</p>
  
  <p>Is there some way to achieve what I meant, using Sourcetree?</p>
  
  <p>(note: it might be nice to have a "sourcetree" tag?)</p>