Re: [PATCH v10 3/4] cat-file: teach cat-file a '--allow-unknown-type' option

[Eric Sunshine <sunshine@sunshineco.com>]

On Sun, May 3, 2015 at 10:30 AM, Karthik Nayak <karthik.188@gmail.com> wrote:
> 'git cat-file' throws an error while trying to print the type or
> size of a broken/corrupt object. This is because these objects are
> usually of unknown types.
>
> Teach git cat-file a '--allow-unknown-type' option where it prints
> the type or size of a broken/corrupt object without throwing
> an error.
>
> Modify '-t' and '-s' options to call sha1_object_info_extended()
> directly to support the '--allow-unknown-type' option.
>
> Add documentation for 'cat-file --allow-unknown-type'.

This round is looking much better than earlier rounds. Just a few very
minor comments below...

> Helped-by: Junio C Hamano <gitster@pobox.com>
> Helped-by: Eric Sunshine <sunshine@sunshineco.com>
> Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
>
> cat-file: add documentation for '--allow-unknown-type' option.
>
> Signed-off-by: Karthik Nayak <karthik.188@gmail.com>

This got botched when you folded the documentation patch into this
one. Drop the redundant "cat-file: add documentation..." line and your
extra sign-off.

> ---
> diff --git a/builtin/cat-file.c b/builtin/cat-file.c
> index 53b5376..ecb4888 100644
> --- a/builtin/cat-file.c
> +++ b/builtin/cat-file.c
> @@ -9,13 +9,20 @@
>  #include "userdiff.h"
>  #include "streaming.h"
>
> -static int cat_one_file(int opt, const char *exp_type, const char *obj_name)
> +static int cat_one_file(int opt, const char *exp_type, const char *obj_name,
> +                       int unknown_type)
>  {
>         unsigned char sha1[20];
>         enum object_type type;
>         char *buf;
>         unsigned long size;
>         struct object_context obj_context;
> +       struct object_info oi = {NULL};
> +       struct strbuf sb = STRBUF_INIT;
> +       unsigned flags = LOOKUP_REPLACE_OBJECT;
> +
> +       if (unknown_type)
> +               flags |= LOOKUP_UNKNOWN_OBJECT;

Nit: 'allow_unknown' (or perhaps 'allow_unknown_type') would be a more
informative variable name than 'unknown_type', and would make this
conditional easier to understand.

>         if (get_sha1_with_context(obj_name, 0, sha1, &obj_context))
>                 die("Not a valid object name %s", obj_name);
> @@ -359,6 +368,7 @@ int cmd_cat_file(int argc, const char **argv, const char *prefix)
>         int opt = 0;
>         const char *exp_type = NULL, *obj_name = NULL;
>         struct batch_options batch = {0};
> +       int unknown_type = 0;

Ditto: s/unknown_type/allow_unknown/

>         const struct option options[] = {
>                 OPT_GROUP(N_("<type> can be one of: blob, tree, commit, tag")),
> @@ -369,6 +379,8 @@ int cmd_cat_file(int argc, const char **argv, const char *prefix)
>                 OPT_CMDMODE('p', NULL, &opt, N_("pretty-print object's content"), 'p'),
>                 OPT_CMDMODE(0, "textconv", &opt,
>                             N_("for blob objects, run textconv on object's content"), 'c'),
> +               OPT_BOOL( 0, "allow-unknown-type", &unknown_type,
> +                         N_("allow -s and -t to work with broken/corrupt objects")),
>                 { OPTION_CALLBACK, 0, "batch", &batch, "format",
>                         N_("show info and content of objects fed from the standard input"),
>                         PARSE_OPT_OPTARG, batch_option_callback },
> @@ -402,5 +414,7 @@ int cmd_cat_file(int argc, const char **argv, const char *prefix)
>         if (batch.enabled)
>                 return batch_objects(&batch);
>
> -       return cat_one_file(opt, exp_type, obj_name);
> +       if (unknown_type && opt != 't' && opt != 's')
> +               die("git cat-file --allow-unknown-type: use with -s or -t");
> +       return cat_one_file(opt, exp_type, obj_name, unknown_type);
>  }
> --
> 2.4.0.rc1.250.gfbd73bd