Subject: Re: [PATCH 1/4] convert: Safer handling of $Id$ contraction.

From: René Scharfe <[email-masked]>
Date: Mon, 15 Mar 2010 19:16:06 +0100

Am 15.03.2010 16:30, schrieb Henrik Grubbström (Grubba):
> The code to contract $Id:xxxxx$ strings could eat an arbitrary amount
> of source text if the terminating $ was lost. It now refuses to
> contract $Id:xxxxx$ strings spanning multiple lines.
> 
> Signed-off-by: Henrik Grubbström <[email-masked]>
> ---
> The behaviour implemented by the patch is in line with what other
> VCSes that implement $Id$ do.
> 
>  convert.c             |   17 +++++++++++++++--
>  t/t0021-conversion.sh |   16 ++++++++++------
>  2 files changed, 25 insertions(+), 8 deletions(-)
> 
> diff --git a/convert.c b/convert.c
> index 4f8fcb7..91207ab 100644
> --- a/convert.c
> +++ b/convert.c
> @@ -425,6 +425,7 @@ static int count_ident(const char *cp, unsigned long size)
>  				cnt++;
>  				break;
>  			}
> +			if (ch == '\n') break;

Style:

			if (ch == '\n')
				break;

>  		}
>  	}
>  	return cnt;
> @@ -433,7 +434,7 @@ static int count_ident(const char *cp, unsigned long size)
>  static int ident_to_git(const char *path, const char *src, size_t len,
>                          struct strbuf *buf, int ident)
>  {
> -	char *dst, *dollar;
> +	char *dst, *dollar, *nl;
>  
>  	if (!ident || !count_ident(src, len))
>  		return 0;
> @@ -455,6 +456,12 @@ static int ident_to_git(const char *path, const char *src, size_t len,
>  			dollar = memchr(src + 3, '$', len - 3);
>  			if (!dollar)
>  				break;
> +			nl = memchr(src + 3, '\n', len - 3);
> +			if (nl && nl < dollar) {
> +				/* Line break before the next dollar. */
> +				continue;
> +			}
> +

You only need to search up to the previously found dollar sign here:

			if (memchr(src + 3, '\n', dollar - src - 3))
				continue;

>  			memcpy(dst, "Id$", 3);
>  			dst += 3;
>  			len -= dollar + 1 - src;
> @@ -470,7 +477,7 @@ static int ident_to_worktree(const char *path, const char *src, size_t len,
>                               struct strbuf *buf, int ident)
>  {
>  	unsigned char sha1[20];
> -	char *to_free = NULL, *dollar;
> +	char *to_free = NULL, *dollar, *nl;
>  	int cnt;
>  
>  	if (!ident)
> @@ -514,6 +521,12 @@ static int ident_to_worktree(const char *path, const char *src, size_t len,
>  				break;
>  			}
>  
> +			nl = memchr(src + 3, '\n', len - 3);
> +			if (nl && nl < dollar) {
> +				/* Line break before the next dollar. */
> +				continue;
> +			}
> +

Ditto.

René