Re: [RFC WIP PATCH 1/3] tag: factor out tag reading from write_tag_body()

[Matheus Tavares Bernardino <matheus.bernardino@usp.br>]

On Tue, Oct 8, 2019 at 3:47 PM Lucas Oshiro <lucasseikioshiro@gmail.com> wrote:
>
> Improve code readability by moving tag reading to a new function called
> get_tag_body, which will be used in the implementation of the git tag
> --amend functionality.

This function is also used in your third patch, to fix git-tag's
--no-edit implementation, right? Maybe you could mention this here,
instead of referencing the --amend feature, as the former is already
present in this series.

> Add warning in write_tag_body() in case the tag body is not successfully
> recovered.
>
> Co-authored-by: Bárbara Fernandes <barbara.dcf@gmail.com>
> Signed-off-by: Bárbara Fernandes <barbara.dcf@gmail.com>
> Signed-off-by: Lucas Oshiro <lucasseikioshiro@gmail.com>
> Helped-by: Matheus Tavares <matheus.bernardino@usp.br>

These tags usually come in chronological order. So I think the
Helped-by should come first as I helped you, then you and Bárbara
co-authored the patch and then, lastly, you sent it.

> ---
>  builtin/tag.c | 42 ++++++++++++++++++++++++++++++++++--------
>  1 file changed, 34 insertions(+), 8 deletions(-)
>
> diff --git a/builtin/tag.c b/builtin/tag.c
> index e0a4c25382..e1e3549af9 100644
> --- a/builtin/tag.c
> +++ b/builtin/tag.c
> @@ -170,26 +170,52 @@ static int git_tag_config(const char *var, const char *value, void *cb)
>         return git_color_default_config(var, value, cb);
>  }
>
> -static void write_tag_body(int fd, const struct object_id *oid)
> +/*
> + * Returns the tag body of the given oid or NULL, in case of error. If size is
> + * not NULL it is assigned the body size in bytes (excluding the '\0').
> + */
> +static char *get_tag_body(const struct object_id *oid, size_t *size)
>  {
> -       unsigned long size;
> +       unsigned long buf_size;
>         enum object_type type;
> -       char *buf, *sp;
> +       char *buf, *sp, *tag_body;
> +       size_t tag_body_size, signature_offset;
>
> -       buf = read_object_file(oid, &type, &size);
> +       buf = read_object_file(oid, &type, &buf_size);
>         if (!buf)
> -               return;
> +               return NULL;
>         /* skip header */
>         sp = strstr(buf, "\n\n");
>
> -       if (!sp || !size || type != OBJ_TAG) {
> +       if (!sp || !buf_size || type != OBJ_TAG) {
>                 free(buf);
> -               return;
> +               return NULL;
>         }
>         sp += 2; /* skip the 2 LFs */
> -       write_or_die(fd, sp, parse_signature(sp, buf + size - sp));
> +       signature_offset = parse_signature(sp, buf + buf_size - sp);
> +       sp[signature_offset] = '\0';
>
> +       /* detach sp from buf */
> +       tag_body_size = strlen(sp) + 1;
> +       tag_body = xmalloc(tag_body_size);
> +       xsnprintf(tag_body, tag_body_size, "%s", sp);
>         free(buf);
> +       if (size)
> +               *size = tag_body_size - 1; /* exclude '\0' */
> +       return tag_body;
> +}
> +
> +static void write_tag_body(int fd, const struct object_id *oid)
> +{
> +       size_t size;
> +       const char *tag_body = get_tag_body(oid, &size);
> +
> +       if (!tag_body) {
> +               warning("failed to get tag body for %s", oid->hash);
> +               return;
> +       }
> +       printf("tag_body: <%s>\n", tag_body);

Hm, is this addition right or perhaps was it added in the patch by mistake?

> +       write_or_die(fd, tag_body, size);
>  }
>
>  static int build_tag_object(struct strbuf *buf, int sign, struct object_id *result)
> --
> 2.23.0
>