Subject: Re: [PATCH] fetch/push: allow refs/*:refs/*

From: Michael Haggerty <[email-masked]>
Date: Sat, 05 May 2012 08:03:56 +0200

On 05/05/2012 12:30 AM, Junio C Hamano wrote:
> There are a handful of places where we call check_refname_format() on a
> substring after "refs/" of a refname we are going to use, and filter out a
> valid match with "refs/stash" with such a pathspec.  Not sending a stash
> may arguably be a feature (as stash is inherently a local workflow
> element), but the code in the transport layer is oblivious to this
> filtering performed by the lower layer of the code, and complains that the
> other side did not send all the objects that needs to complete refs/stash
> at the end, even though the code will not write refs/stash out anyway, and
> making the whole command fail.
>
> This is an attempt to "fix" it by using check_refname_format() on the
> whole "refs/....." string and allowing refs/stash to be also copied.
>
> Signed-off-by: Junio C Hamano<[email-masked]>
> ---
>
>   * With this patch:
>
>      $ git checkout HEAD^0 ;# make sure we are on detached HEAD
>      $ git fetch $somewhere +refs/*:refs/*
>
>     and
>
>      victim$ git config receive.denyCurrentBranch warn
>      master$ git push victim +refs/*:refs/*
>
>     should work.
>
>   builtin/fetch-pack.c   |  2 +-
>   builtin/receive-pack.c |  2 +-
>   remote.c               |  2 +-
>   t/t5516-fetch-push.sh  | 30 ++++++++++++++++++++++++++++++
>   4 files changed, 33 insertions(+), 3 deletions(-)
>
> diff --git a/builtin/fetch-pack.c b/builtin/fetch-pack.c
> index 6207ecd..a3e3fa3 100644
> --- a/builtin/fetch-pack.c
> +++ b/builtin/fetch-pack.c
> @@ -546,7 +546,7 @@ static void filter_refs(struct ref **refs, int nr_match, char **match)
>   	for (ref = *refs; ref; ref = next) {
>   		next = ref->next;
>   		if (!memcmp(ref->name, "refs/", 5)&&
> -		    check_refname_format(ref->name + 5, 0))
> +		    check_refname_format(ref->name, 0))

The patch looks fine to me.

This combination "!memcmp(ref->name, "refs/", 5) && 
check_refname_format(ref->name, 0)" is the reason that I suggested 
adding a REFNAME_FULL option [1], in which case it could be written 
"check_refname_format(ref->name, REFNAME_FULL)".  However, now I think 
that the options should be constructed a little differently:

flags==0: Require refname to start with "refs/"

flags==REFNAME_ALLOW_SPECIAL: Also accept single-level ALL_CAPS refnames.

flags==REFNAME_ALLOW_PARTIAL: Don't check the namespace or require '/'). 
  This could be used for checking partial names like "master" as 
shorthand for "refs/master".

Does this sound reasonable to you?

Michael

[1] http://article.gmane.org/gmane.comp.version-control.git/196632

>   			; /* trash */
>   		else if (args.fetch_all&&
>   			(!args.depth || prefixcmp(ref->name, "refs/tags/") )) {
> diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
> index 7ec68a1..1935b80 100644
> --- a/builtin/receive-pack.c
> +++ b/builtin/receive-pack.c
> @@ -401,7 +401,7 @@ static const char *update(struct command *cmd)
>   	struct ref_lock *lock;
>
>   	/* only refs/... are allowed */
> -	if (prefixcmp(name, "refs/") || check_refname_format(name + 5, 0)) {
> +	if (prefixcmp(name, "refs/") || check_refname_format(name, 0)) {
>   		rp_error("refusing to create funny ref '%s' remotely", name);
>   		return "funny refname";
>   	}
> diff --git a/remote.c b/remote.c
> index e2ef991..eacd8ad 100644
> --- a/remote.c
> +++ b/remote.c
> @@ -1595,7 +1595,7 @@ static int one_local_ref(const char *refname, const unsigned char *sha1, int fla
>   	int len;
>
>   	/* we already know it starts with refs/ to get here */
> -	if (check_refname_format(refname + 5, 0))
> +	if (check_refname_format(refname, 0))
>   		return 0;
>
>   	len = strlen(refname) + 1;
> diff --git a/t/t5516-fetch-push.sh b/t/t5516-fetch-push.sh
> index b69cf57..1a45b19 100755
> --- a/t/t5516-fetch-push.sh
> +++ b/t/t5516-fetch-push.sh
> @@ -929,6 +929,36 @@ test_expect_success 'push into aliased refs (inconsistent)' '
>   	)
>   '
>
> +test_expect_success 'push all hierarchies with stash' '
> +	mk_empty&&
> +	git stash clear&&
> +	git reset --hard&&
> +	echo>>path1&&
> +	git stash save "Tweak path1"&&
> +	git push testrepo "refs/*:refs/*"&&
> +	git ls-remote .>expect&&
> +	git ls-remote testrepo>actual&&
> +	test_cmp actual expect
> +'
> +
> +test_expect_success 'fetch all hierarchies with stash' '
> +	mk_empty&&
> +	git stash clear&&
> +	git reset --hard&&
> +	echo>>path1&&
> +	git stash save "Tweak path1"&&
> +	(
> +		cd testrepo&&
> +		git commit --allow-empty -m initial&&
> +		git checkout HEAD^0&&
> +		git fetch .. "+refs/*:refs/*"&&
> +		git checkout master
> +	)&&
> +	git ls-remote .>expect&&
> +	git ls-remote testrepo>actual&&
> +	test_cmp actual expect
> +'
> +
>   test_expect_success 'push --porcelain' '
>   	mk_empty&&
>   	echo>.git/foo  "To testrepo"&&

-- 
Michael Haggerty
[email-masked]
http://softwareswirl.blogspot.com/