revision: allow --end-of-options to end option parsing

There's currently no robust way to tell Git that a particular option is meant to be a revision, and not an option. So if you have a branch "refs/heads/--foo", you cannot just say: git rev-list --foo You can say: git rev-list refs/heads/--foo But that breaks down if you don't know the refname, and in particular if you're a script passing along a value from elsewhere. In most programs, you can use "--" to end option parsing, like this: some-prog -- "$revision" But that doesn't work for the revision parser, because "--" is already meaningful there: it separates revisions from pathspecs. So we need some other marker to separate options from revisions. This patch introduces "--end-of-options", which serves that purpose: git rev-list --oneline --end-of-options "$revision" will work regardless of what's in "$revision" (well, if you say "--" it may fail, but it won't do something dangerous, like triggering an unexpected option). The name is verbose, but that's probably a good thing; this is meant to be used for scripted invocations where readability is more important than terseness. One alternative would be to introduce an explicit option to mark a revision, like: git rev-list --oneline --revision="$revision" That's slightly _more_ informative than this commit (because it makes even something silly like "--" unambiguous). But the pattern of using a separator like "--" is well established in git and in other commands, and it makes some scripting tasks simpler like: git rev-list --end-of-options "$@" There's no documentation in this patch, because it will make sense to describe the feature once it is available everywhere (and support will be added in further patches). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>