Diffs not showing properly when viewing a changeset. (BB-3272)

After the side-by-side diff feature was rolled out, some of my diffs are not showing up correctly. This is not happening on all of our repositories and we cannot see any pattern as to why some of them are correct and some are not.

This occurs when looking under the commits tab and clicking on one of the revisions. On some of the repos, I only get a "File attributes modified." statement for a file even though it is only a text file and is easily diffable. These same files showed a proper context-diff before the new side-by-side style was rolled out.

See the attached screenshot. It was created in a private repository here:

https://bitbucket.org/CPCSSN/source-code-templates-guidelines/changeset/d9aabfd75e58