From: Junio C Hamano <gitster@pobox.com>
Date: Wed, 15 Dec 2010 23:44:12 GMT
Subject: Re: [PATCH] get_sha1: handle special case $commit^{/}
Message-ID: <7v8vzqppo3.fsf@alter.siamese.dyndns.org>
In-Reply-To: <1292403774-361-1-git-send-email-pclouds@gmail.com>

Nguyễn Thái Ngọc Duy <pclouds@gmail.com> writes:

> Empty regex pattern should always match. But the exact behavior of
> regexec() may vary. Because it always matches anyway, we can just
> return 'matched' without calling regex machinery.

Hmm, I just noticed that "git grep -e '' Makefile" fails on FBSD8 for
the same reason.

I'd prefer a solution that is not about "special case $commit^{/}" but is
about "work around regcomp that cannot compile an empty regexp".

Wisdoms?

> Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
> ---
>  On top of nd/oneline-sha1-name-from-specific-ref
>
>  sha1_name.c |    7 +++++++
>  1 files changed, 7 insertions(+), 0 deletions(-)
>
> diff --git a/sha1_name.c b/sha1_name.c
> index 1ba4bc3..c5c59ce 100644
> --- a/sha1_name.c
> +++ b/sha1_name.c
> @@ -599,6 +599,13 @@ static int peel_onion(const char *name, int len, unsigned char *sha1)
>  		int ret;
>  		struct commit_list *list = NULL;
>  
> +		/*
> +		 * $commit^{/}. Some regex implementation may reject.
> +		 * We don't need regex anyway. '' pattern always matches.
> +		 */
> +		if (sp[1] == '}')
> +			return 0;
> +
>  		prefix = xstrndup(sp + 1, name + len - 1 - (sp + 1));
>  		commit_list_insert((struct commit *)o, &list);
>  		ret = get_sha1_oneline(prefix, sha1, list);
> -- 
> 1.7.3.3.476.g10a82