title: GitHub pull request from private to public repo possible?
body: <p>I forked a public repo and made the new repo private.</p>
  
  <p>I added a new remote branch on my private repo with some fixes committed.</p>
  
  <p>Now, I want to create a pull request from the branch in my private repo towards the public repo I forked from.</p>
  
  <p>I select the branch in my private repo and click "Pull request".</p>
  
  <p>I click on "Change commits".</p>
  
  <p>I can't change the organisation/repo owner. I only see my organisation, but not the one of the public repo. I could only create a pull request against master branch of my private repo, but that's not what I want.</p>
  
  <p>Is it not possible to fix something of a public repo in a private one and create a pull request afterwards?</p>