Re: git hang with corrupted .pack

From: Nicolas Pitre <nico@fluxnic.net>
Date: Oct 20, 2009, 19:46 UTC
Message-ID: <alpine.LFD.2.00.0910201538180.21460@xanadu.home>
In-Reply-To: <7vpr8hn9ly.fsf@alter.siamese.dyndns.org>

On Tue, 20 Oct 2009, Junio C Hamano wrote:

Show 18 quoted lines

> Perhaps it would be as simple as this?
> 
> We deliberately give one byte more than what we expect to see and error
> out when we do get that extra byte filled.
> 
>  sha1_file.c |   17 +++++++++--------
>  1 files changed, 9 insertions(+), 8 deletions(-)
> 
> diff --git a/sha1_file.c b/sha1_file.c
> index 4cc8939..8c9f392 100644
> --- a/sha1_file.c
> +++ b/sha1_file.c
> @@ -1344,7 +1344,7 @@ unsigned long get_size_from_delta(struct packed_git *p,
>  			          off_t curpos)
>  {
>  	const unsigned char *data;
> -	unsigned char delta_head[20], *in;
> +	unsigned char delta_head[21], *in;

I didn't spend the time needed to think about this issue and your proposed fix yet. However I think that using sizeof(delta_head)-1 makes the code a bit confusing. At this point i'd use:

	int size = sizeof(delta_head) - 1;

and use that variable instead just like it is done in unpack_compressed_entry() to have the same code pattern.

Nicolas