Bug 1422729 - Produce an error when trying to diff a documentation file, instead of panicking
Bug 1422729 - Produce an error when trying to diff a documentation file, instead of panicking

bill-mccloskey/searchfox,bill-mccloskey/searchfox,bill-mccloskey/searchfox,bill-mccloskey/searchfox,bill-mccloskey/searchfox,bill-mccloskey/searchfox