magit/magit — pull request #1539 by drothlis (2014-10-08 22:01:42+00:00)
Title: git push "-f" switch uses --force-with-lease instead of --force

See the commit message for details.

This won't work with git < 1.8.5 (which was released November 2013) -- I don't know what your policy is for supporting older versions of git?