title: Cherry-pick a merge
body: <p>Let's say branch B is a topic branch off of branch A, and you want those changes in branch C.  What does it mean when you cherry-pick the merge commit of branch A and branch B to branch C?</p>
  
  <p>For example, if you use the -m flag to specify the old HEAD of branch A to cherry-pick the merge to branch C, does that simply mean "Take the diff between the cherry-picked commit tree and old HEAD of branch A and apply it to branch C?"</p>
  
  <p>Are there any gotchas for using this method? (e.g. Would branch C look like it's merged to branch A and B?  Would more changes be applied than simply the commits from branch B?)</p>