Re: [PATCH GSoC v20 00/13] cat-file: add remote-object-info to batch-command

> Changes in v20:
> - Moved the prep patch that fixes hash_algo's type to be before
>   write_fetch_command_and_capabilities() being moved to 'connect.c'
> - Reverted git-cat-file.adoc documentation comments about CAVEATS
> - Fixed style for EXPAND_DATA_INIT
> - Added more context for comman line die()
>

> Range-diff versus v19:
>
>  1:  6df5bcb3bc =  1:  31b02f10b5 transport-helper: fix memory leak of helper on disconnect
>  2:  141d85a76f =  2:  7d62e0586f cat-file: declare loop counter inside for()
>  3:  87457a1fe3 =  3:  082d593fb7 t1006: extract helper functions into new 'lib-cat-file.sh'
>  4:  c26d378931 =  4:  8646b9d7cf fetch-pack: drop the static advertise_sid variable
>  -:  ---------- >  5:  5531a3c399 fetch-pack: use unsigned int for hash_algo variable
>  5:  ee16e17228 !  6:  92b4122642 fetch-pack: move write_fetch_command_and_capabilities() to connect.c
>     @@ connect.c: int server_supports(const char *feature)
>      +	}
>      +
>      +	if (server_feature_v2("object-format", &hash_name)) {
>     -+		int hash_algo = hash_algo_by_name(hash_name);
>     ++		const unsigned int hash_algo = hash_algo_by_name(hash_name);
>      +		if (hash_algo_by_ptr(the_hash_algo) != hash_algo)
>      +			die(_("mismatched algorithms: client %s; server %s"),
>      +			    the_hash_algo->name, hash_name);
>     @@ fetch-pack.c: static int add_haves(struct fetch_negotiator *negotiator,
>      -	}
>      -
>      -	if (server_feature_v2("object-format", &hash_name)) {
>     --		int hash_algo = hash_algo_by_name(hash_name);
>     +-		const unsigned int hash_algo = hash_algo_by_name(hash_name);
>      -		if (hash_algo_by_ptr(the_hash_algo) != hash_algo)
>      -			die(_("mismatched algorithms: client %s; server %s"),
>      -			    the_hash_algo->name, hash_name);
>  6:  bb915f57ad <  -:  ---------- connect: use unsigned int for hash_algo_by_name() calls
>  7:  b3b06b0cae =  7:  b954a5994a connect: make write_fetch_command_and_capabilities() more generic
>  8:  79a87c7011 =  8:  627242a7a1 fetch-pack: move fetch initialization
>  9:  37c3f93975 =  9:  0578594733 protocol-caps: check object existence regardless of the attributes requested
> 10:  c5062ecaf2 = 10:  816bfa9162 serve: advertise object-info feature
> 11:  22d72168bc = 11:  2323f45cb2 transport: add client support for object-info
> 12:  2cf3b24a35 ! 12:  a39975766b cat-file: add remote-object-info to batch-command
>     @@ Documentation/git-cat-file.adoc: one per line, and print information based on th
>       You can specify the information shown for each object by using a custom
>       `<format>`. The `<format>` is copied literally to stdout for each
>      @@ Documentation/git-cat-file.adoc: newline. The available atoms are:
>     - 	reports).
>     -
>     - `objectsize:disk`::
>     --	The size, in bytes, that the object takes up on disk. See the
>     --	note about on-disk sizes in the `CAVEATS` section below.
>     -+	The size, in bytes, that the object takes up on disk.
>     -
>       `deltabase`::
>       	If the object is stored as a delta on-disk, this expands to the
>       	full hex representation of the delta base object name.
>      -	Otherwise, expands to the null OID (all zeroes). See `CAVEATS`
>     --	below.
>     -+	Otherwise, expands to the null OID (all zeroes).
>     ++	Otherwise, expands to the null OID (all zeroes). See `CAVEATS` section
>     + 	below.
>

>       `rest`::
>     - 	If this atom is used in the output string, input lines are split
>      @@ Documentation/git-cat-file.adoc: newline. The available atoms are:
>       	after that first run of whitespace (i.e., the "rest" of the
>       	line) are output in place of the `%(rest)` atom.
>     @@ builtin/cat-file.c: struct expand_data {
>      +	 */
>      +	unsigned is_remote:1;
>      +};
>     ++
>      +#define EXPAND_DATA_INIT  { .mode = S_IFINVALID, .type = OBJ_BAD }
>      +
>      +static const char *remote_object_info_atoms[] = {
>     @@ builtin/cat-file.c: static void parse_cmd_mailmap(struct batch_options *opt UNUS
>      +	line_to_split = xstrdup(line);
>      +	count = split_cmdline(line_to_split, &argv);
>      +	if (count < 0)
>     -+		die(_("remote-object-info: %s"), split_cmdline_strerror(count));
>     ++		die(_("remote-object-info: failed to parse command line: %s"),
>     ++		    split_cmdline_strerror(count));
>      +	if (count - 1 > MAX_ALLOWED_OBJ_LIMIT)
>      +		die(_("remote-object-info supports at most %d objects"),
>      +		    MAX_ALLOWED_OBJ_LIMIT);
> 13:  ebdfc22fb7 ! 13:  70a11d2aea cat-file: make remote-object-info allow-list adapt to the server
>     @@ builtin/cat-file.c: struct expand_data {
>       	 */
>       	unsigned is_remote:1;
>      -};
>     +-
>      -#define EXPAND_DATA_INIT  { .mode = S_IFINVALID, .type = OBJ_BAD }
>
>      -static const char *remote_object_info_atoms[] = {
>      -	"objectname",
>      -	"objectsize",
>     ++	/*
>     ++	 * List of atoms (i.e. "objectsize") that the server supports. Built
>     ++	 * from the server's object-info advertised capabilities.
>     ++	 */
>      +	struct string_list remote_allowed_atoms;
>       };
>     -+#define EXPAND_DATA_INIT  { .mode = S_IFINVALID, .type = OBJ_BAD, \
>     -+			    .remote_allowed_atoms = STRING_LIST_INIT_NODUP }
>
>     ++#define EXPAND_DATA_INIT  { .mode = S_IFINVALID, \
>     ++			    .type = OBJ_BAD, \
>     ++			    .remote_allowed_atoms = STRING_LIST_INIT_NODUP }
>     ++

>       static int is_atom(const char *atom, const char *s, int slen)
>       {
>     + 	int alen = strlen(atom);
>      @@ builtin/cat-file.c: static int expand_atom(struct strbuf *sb, const char *atom, int len,
>       		       struct expand_data *data)
>       {
>     @@ builtin/cat-file.c: static int expand_atom(struct strbuf *sb, const char *atom,
>      -			if (is_atom(remote_object_info_atoms[i], atom, len))
>      +		size_t i;
>      +		for (i = 0; i < data->remote_allowed_atoms.nr; i++)
>     -+			if (is_atom(data->remote_allowed_atoms.items[i].string, atom, len))
>     ++			if (is_atom(data->remote_allowed_atoms.items[i].string,
>     ++				    atom, len))
>       				break;
>      -
>      -		/*
>
> ---
> base-commit: 44de1520f08d1dfebc3ab2d9f644208eaa5ac925