title: How to git merge changes from main branch to orphan branch without adding to orphan's history?
body: <p>I have a git repository for my phd dissertation (in latex). The university policies does not allow me to share the background review chapter of my dissertation with my research adviser, I am free to share and get opinion for other chapters.</p>
  
  <p>To share the repository with my advisor I created an orphan branch (noRevBranch) with the required chapter removed and pushed and tracked this branch to a new repository on github.
  I can share this with his and he can not access the removed chapter because there is no history here.</p>
  
  <p>The question is how do I merge any changes I make to the master branch in the future to the noRevBranch without also appending the master branch history to the new merge commit?</p>