From: Junio C Hamano <gitster@pobox.com>
Date: Mon, 03 Mar 2014 19:05:16 GMT
Subject: Re: [PATCH v3] skip_prefix: rewrite so that prefix is scanned once
Message-ID: <xmqqvbvvp0gj.fsf@gitster.dls.corp.google.com>
In-Reply-To: <1393816384-3300-1-git-send-email-siddharth98391@gmail.com>

Siddharth Goel <siddharth98391@gmail.com> writes:

> Helped-by: Eric Sunshine <sunshine@sunshineco.com>
> Signed-off-by: Siddharth Goel <siddharth98391@gmail.com>
> ---
> Added a space after colon in the subject as compared to previous 
> patch [PATCH v2].
>
> [PATCH v2]: http://thread.gmane.org/gmane.comp.version-control.git/243150

Whenever you see "Change", "Rewrite", etc. in the subject of a patch
that touches existing code, think twice.  The subject line is a
scarce real estate to be wasted on a noiseword that carries no real
information, and we already know a patch that touches existing code
changes or rewrites things.

    Subject: [PATCH v3] skip_prefix: scan prefix only once

perhaps?

>  git-compat-util.h | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/git-compat-util.h b/git-compat-util.h
> index 614a5e9..550dce3 100644
> --- a/git-compat-util.h
> +++ b/git-compat-util.h
> @@ -357,8 +357,11 @@ extern int suffixcmp(const char *str, const char *suffix);
>  
>  static inline const char *skip_prefix(const char *str, const char *prefix)
>  {
> -	size_t len = strlen(prefix);
> -	return strncmp(str, prefix, len) ? NULL : str + len;
> +	while (*prefix != '\0' && *str == *prefix) {
> +		str++;
> +		prefix++;
> +	}
> +	return (*prefix == '\0' ? str : NULL);

Unlike another patch I saw the other day on the same topic, this
checks *prefix twice for the last round, even though I think this
one is probably slightly easier to read.  I dunno.