Re: [issue?]'git branch -D' case sensitive issue

From: Junio C Hamano <gitster@pobox.com>
Date: Jan 14, 2016, 17:21 UTC
Message-ID: <xmqq4megkrf9.fsf@gitster.mtv.corp.google.com>
In-Reply-To: <5697CFEB.4090308@web.de>

Torsten Bögershausen <tboegi@web.de> writes:

> No, this is typically what we observe on a case insensitive FS.

There is an interesting bit in delete_branches::builtin/branch.c

	if (kinds == FILTER_REFS_BRANCHES && !strcmp(head, bname.buf)) {
		error(_("Cannot delete the branch '%s' "
		      "which you are currently on."), bname.buf);
		ret = 1;
		continue;
	}

The strcmp() does not protect you from attempting to remove "FrOtZ" branch when you are on (and more importantly, Git thinks you are on) "frotz" branch. A case-insensitive system then can tell Git that the request to remove "refs/heads/FrOtZ" succeeded, even though in reality it didn't have such file, and silently "refs/heads/frotz" gets removed instead. You can end up removing your current branch that way.