Goodafternoon, 

while trying to reduce conflicts on a changelog file, i tried eliminating conflicts using the .gitattributes with union defined for the CHANGELOG_UPCOMING.md file. I included the steps to come to this very strange issue. In the enclosed PDF, I tried to specify all the commands so it is easy to reproduce this strange issue which I hope is not a works as designed.

In case still something not clear. I’m happy to assist.