title: Github: Changes ignored after revert (git cherrypick, git rebase)
body: <p>Lets say I have two branches <code>A</code> and <code>B</code></p>
  
  <pre><code>(A)--------(A+B)--------------(A+B+R)
   \        / merge   \ revert  /
    \      /           \       /
   (B)----(B+)         (R)----
  </code></pre>
  
  <p>First, I merged branch <code>B</code> to <code>A</code>,
  Then I reverted the merge request with GitHub's revert feature.</p>
  
  <p>Now when I fix some code on branch <code>B</code> and need to merge to <code>A</code> again, <strong>almost all</strong> changes (except the new one that I fix) are ignored. How can I get the changes again?</p>