Re: [PATCH v3] git checkout -b: unparent the new branch with -o

Jonathan Nieder <jrnieder@gmail.com> writes:

If we have the "just detach, don't touch index nor working tree", which happens to be the cheapest one in the middle (except that it probably wants to verify that "new" does not exist yet), the calling script of the Porcelain suite can use it in conjunction with various forms of "git rm" without incurring any additional overhead (other than a fork-and-exec), and I think that would be sufficient.

You could add

	git ls-files |
        while read path
        do
        	case $(choose-keep-drop-nuke "$path") in
                keep) ;;
                drop) git rm --cached -f "$path" ;;
                nuke) git rm -f "$path" ;;
        	esac
	done
	git symbolic-ref HEAD refs/heads/new

and have the caller supply a callback that intelligently choose what to keep and what to drop, if you want to be really fancy, but at that level of complexity, I think it is something the Porcelain writer using the plumbing would want to write himself as part of the Porcelain program.

We might want to add "git branch --switch <branchname>" that is roughly like this:

    ref="refs/heads/$branch"
    git check-ref-format "$ref" || die "malformed"
    if git rev-parse -q --verify "$ref" >/dev/null
    then
    	# exists
        exec git checkout "$branch"
    else
	# create
	exec git symbolic-ref HEAD "$ref"
    fi