Error 500 trying to view a merge request JSON: undefined method `binary?' for nil:NilClass

Try with: https://gitlab.com/gitlab-org/gitlab-workhorse/merge_requests/4/diffs.json

https://sentry.gitlap.com/gitlab/gitlabcom/issues/116009/

NoMethodError: undefined method `binary?' for nil:NilClass
  lib/gitlab/diff/file.rb:174:in `binary?'
    has_binary_notice? || old_blob&.binary? || new_blob&.binary?
  lib/gitlab/metrics/instrumentation.rb:159:in `block in binary?'
    .measure { super }
  lib/gitlab/metrics/method_call.rb:47:in `measure'
    retval = yield
  lib/gitlab/metrics/instrumentation.rb:159:in `binary?'
    .measure { super }
  lib/gitlab/diff/file.rb:178:in `text?'
    !binary?
...
(184 additional frame(s) were not displayed)

ActionView::Template::Error: undefined method `binary?' for nil:NilClass

ActionView::Template::Error: undefined method `binary?' for nil:NilClass