If the source ref is behind the target ref, then the diff and commits tabs will show "No changes" and "No commits found" respectively.

This leads some customers to think the page is broken. Possible solution could be one of the following:

1. Clarify the type of diff we're using (triple dot, not double dot) so they know what to expect
2. When there are no changes, offer a suggestion link that will swap the source and destination. E.g. "No commits found. Try swapping the refs."