rev-parse, unknown arguments and extended sha1's

[Sven Verdoolaege <skimo@liacs.nl>]

Is git-rev-parse supposed to echo arguments it doesn't understand ?
It currently does, but git-checkout-script seems to think it doesn't:

                rev=$(git-rev-parse "$arg")   
                if [ -z "$rev" ]; then
                        echo "unknown flag $arg"
                        exit 1
                fi

Also, is there any reason why the extended sha1 notation
is restricted to the scripts and not used in the actual
plumbing ?

skimo