These are the supported media types for pull requests. You can read more about the use of media types in the API here.
application/vnd.github.VERSION.raw+json
application/vnd.github.VERSION.text+json
application/vnd.github.VERSION.html+json
application/vnd.github.VERSION.full+json
application/vnd.github.VERSION.diff
application/vnd.github.VERSION.patch
If a diff is corrupt, contact GitHub Support or GitHub Premium Support. Include the repository name and pull request ID in your message.