title: How can I preview a merge in git?
body: <p>I have a git branch (the mainline, for example) and I want to merge in another development branch. Or do I?</p>
  
  <p>In order to decide whether I really want to merge this branch in, i'd like to see some sort of preview of what the merge will do. Preferably with the ability to see the list of commits that are being applied.</p>
  
  <p>So far, the best I can come up with is <code>merge --no-ff --no-commit</code>, and then <code>diff HEAD</code>.</p>