title: How to merge code after prettify ran upstream
body: <p>I'm maintaining a fork of an open source project where we pull approximately every month from upstream in order not to branch too much.</p>
  <p>When I tried to pull from upstream this month I found out they ran prettify (or some other equivalent) over the entire code (~15,000 files) and virtually every change we've made in our fork since the last pull (and there were quite a lot) causes conflicts.</p>
  <p>Anyone ever ran into this issue? Would appreciate any help if there's any way to merge this faster than manually 3-way merging every file.</p>
  <p>Thank you.</p>
  <p>EDIT: I do not have write access to the upstream project, from my perspective it's read only.</p>