I work on Rails project in my Emacs25.
When I change one specific file and save changes I got all file changed (from git diff). But when I try to old and new versions of this file in Meld - I get difference with only my few strings changes.
In this .rb file has linux line separator, 2 spaces tabulation just like in whole project. There is a place to be only in this file (maybe other files has it but the most of don't).
Most important thing: I changed this file before many times with no problems.