Drop Windows-linefeeds already in repo

git config --system core.autocrlf false
git filter-branch -f --prune-empty --tree-filter 'git ls-files -z | xargs -0 dos2unix' -- --all
git config --system core.autocrlf true
echo '* text=auto' >> .gitattributes

But only as a reaction to things gone bad. As a general rule of thumb, always start your git projects/imports by:

git config core.autocrlf true
echo '* text=auto' >> .gitattributes