gitsum is an add-on, not a full-featured git mode; so is git-dwim, I believe, although I don't use it personally.
Recent Emacs have git support in VC; I tend to just use that since I tend to do anything other than committing (rebasing, switching branches, merging, pushing, etc.) in a terminal.
Recent Emacs have git support in VC; I tend to just use that since I tend to do anything other than committing (rebasing, switching branches, merging, pushing, etc.) in a terminal.