The consequence of reverting a merge and how it should be handled when the re-merging.
https://stackoverflow.com/questions/1078146/re-doing-a-reverted-merge-in-git
http://blog.jdwyah.com/2015/07/dealing-with-git-merge-revisions.html
Official source
https://mirrors.edge.kernel.org/pub/software/scm/git/docs/howto/revert-a-faulty-merge.txt