title: Gerrit: Pushing for code review a commit that's already on Gerrit
body: <p>My workplace started using Gerrit to manage all of our projects. I've never used Gerrit before. I'm trying to figure out a good workflow for using it for submitting code for review.</p>
  
  <p>I created a branch <code>foo</code>. I made a commit on it, and pushed it to Gerrit. Then I started a branch <code>bar</code> starting from <code>foo</code>, and made another commit on it. I pushed the branch <code>bar</code> to Gerrit as well. </p>
  
  <p>I am now on branch <code>bar</code>:</p>
  
  <pre><code>$ git branch
  * bar
  foo
  </code></pre>
  
  <p>Now I wanted to start a code review for a merge from <code>bar</code> to <code>foo</code>. I was told that this command should do it: </p>
  
  <pre><code>$ git push gerrit HEAD:refs/for/foo
  Total 0 (delta 0), reused 0 (delta 0)
  remote:
  remote: Processing changes: refs: 1, done
  To ssh://ram@gerrit/acme/my_project
   ! [remote rejected] HEAD -&gt; refs/for/foo (no new changes)
  error: failed to push some refs to 'ssh://ram@gerrit/acme/my_project' 
  </code></pre>
  
  <p>As you can see, I'm getting the error <code>(no new changes)</code>. I asked our local Gerrit champion why, and he says that as far as he knows, you can't push for code review code that's already on Gerrit, even if that code is on a different branch.</p>
  
  <p>It looks like if I'd avoid pushing the branch <code>bar</code> to Gerrit, my problem would go away and the code review would work. <strong>But I would prefer to be able to push whatever the %&amp;@# I want without it interfering with code reviews.</strong> I like pushing branches. I like having my branches on Gerrit, because then I can also send them to other people to see on the web interface. </p>
  
  <p><strong>Is it possible to make code reviews in Gerrit work without forbidding me from pushing my branches to Gerrit?</strong></p>