Re: Teach "git checkout" to use git-show-ref

[Junio C Hamano <junkio@cox.net>]

Linus Torvalds <torvalds@osdl.org> writes:

> That way, it doesn't care how the refs are stored any more
>
> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
> ---
>
> Just as an example of how to use git-show-ref rather than knowing about 
> "$GIT_DIR/refs/..." paths.
>
> This basically replaces my much hackier version that is in the "lt/refs" 
> branch, but can go into the master branch independently of the 
> refs-packing work.

I kind of liked the rev-parse one better for this particular
command, but only slightly (by using --verify on "$arg^0", you
were also making sure what's in refs/heads/ was a commit object,
but that check is gone with this patch.  It is not a loss,
because the original code did not check it, and nobody should be
placing anything but commits under refs/heads anyway).

> diff --git a/git-checkout.sh b/git-checkout.sh
> index 580a9e8..6e4c535 100755
> --- a/git-checkout.sh
> +++ b/git-checkout.sh
>...
> @@ -51,7 +51,7 @@ while [ "$#" != "0" ]; do
>  			fi
>  			new="$rev"
>  			new_name="$arg^0"
> -			if [ -f "$GIT_DIR/refs/heads/$arg" ]; then
> +			if git-show-ref --verify --quiet -- "refs/heads/$arg" ]; then
>  				branch="$arg"
>  			fi
>  		elif rev=$(git-rev-parse --verify "$arg^{tree}" 2>/dev/null)