Re: [PATCH 0/5] teach replace objects to sha1_object_info_extended()

[Junio C Hamano <gitster@pobox.com>]

Jeff King <peff@peff.net> writes:

> On Mon, Dec 02, 2013 at 09:52:25AM -0500, Jeff King wrote:
>
>> I find it a little funny that we reuse the READ_SHA1_FILE_REPLACE flag
>> directly in lookup_replace_object. That means that it is now a
>> meaningful flag for sha1_object_info_extended, even though the name does
>> not say so. It also means that the two may have to coordinate further
>> flags (since a portion of their flag namespace is shared by
>> lookup_replace_object). I don't foresee adding a lot of new flags,
>> though, so it probably isn't a huge deal.
>> 
>> I also would have expected sha1_object_info_extended to simply receive
>> the new flag via the struct object_info. Again, probably not a big deal,
>> because there aren't many callsites that needed updating. But if we were
>> not sharing flags with read_sha1_file, I think doing it as a flag in the
>> struct would be nicer.
>
> Curious what this would look like, I wrote the patch. If you drop your
> patches 2 and 3, then your final patch (actually fixing the problem)
> would look like the one below:
>
> We may be getting into bikeshed territory, and I don't feel
> super-strongly about it, so I won't say anything more. Now we've seen
> both alternatives, and you or Junio can pick. :)

FWIW, I shared that "a little funny" feeling ;-)

>
> ---
> diff --git a/builtin/cat-file.c b/builtin/cat-file.c
> index b2ca775..a2e3e26 100644
> --- a/builtin/cat-file.c
> +++ b/builtin/cat-file.c
> @@ -270,6 +270,7 @@ static int batch_objects(struct batch_options *opt)
>  	 * object.
>  	 */
>  	memset(&data, 0, sizeof(data));
> +	data.info.respect_replace = 1;
>  	data.mark_query = 1;
>  	strbuf_expand(&buf, opt->format, expand_format, &data);
>  	data.mark_query = 0;
> diff --git a/cache.h b/cache.h
> index ce377e1..0ad262f 100644
> --- a/cache.h
> +++ b/cache.h
> @@ -1074,6 +1074,7 @@ struct object_info {
>  	enum object_type *typep;
>  	unsigned long *sizep;
>  	unsigned long *disk_sizep;
> +	unsigned respect_replace:1;
>  
>  	/* Response */
>  	enum {
> diff --git a/sha1_file.c b/sha1_file.c
> index 7dadd04..b6ddad0 100644
> --- a/sha1_file.c
> +++ b/sha1_file.c
> @@ -2519,8 +2519,11 @@ int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi)
>  	struct cached_object *co;
>  	struct pack_entry e;
>  	int rtype;
> +	const unsigned char *real = oi->respect_replace ?
> +				    lookup_replace_object(sha1) :
> +				    sha1;
>  
> -	co = find_cached_object(sha1);
> +	co = find_cached_object(real);
>  	if (co) {
>  		if (oi->typep)
>  			*(oi->typep) = co->type;
> @@ -2532,16 +2535,16 @@ int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi)
>  		return 0;
>  	}
>  
> -	if (!find_pack_entry(sha1, &e)) {
> +	if (!find_pack_entry(real, &e)) {
>  		/* Most likely it's a loose object. */
> -		if (!sha1_loose_object_info(sha1, oi)) {
> +		if (!sha1_loose_object_info(real, oi)) {
>  			oi->whence = OI_LOOSE;
>  			return 0;
>  		}
>  
>  		/* Not a loose object; someone else may have just packed it. */
>  		reprepare_packed_git();
> -		if (!find_pack_entry(sha1, &e))
> +		if (!find_pack_entry(real, &e))
>  			return -1;
>  	}
>  
> @@ -2570,6 +2573,7 @@ int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
>  
>  	oi.typep = &type;
>  	oi.sizep = sizep;
> +	oi.respect_replace = 1;
>  	if (sha1_object_info_extended(sha1, &oi) < 0)
>  		return -1;
>  	return type;
> diff --git a/t/t6050-replace.sh b/t/t6050-replace.sh
> index b90dbdc..bb785ec 100755
> --- a/t/t6050-replace.sh
> +++ b/t/t6050-replace.sh
> @@ -276,7 +276,7 @@ test_expect_success '-f option bypasses the type check' '
>  	git replace -f HEAD^ $BLOB
>  '
>  
> -test_expect_failure 'git cat-file --batch works on replace objects' '
> +test_expect_success 'git cat-file --batch works on replace objects' '
>  	git replace | grep $PARA3 &&
>  	echo $PARA3 | git cat-file --batch
>  '