Re: [RFC/PATCH] notes.c: replace git_config with git_config_get_string

[Eric Sunshine <sunshine@sunshineco.com>]

On Mon, Jun 23, 2014 at 6:41 AM, Tanay Abhra <tanayabh@gmail.com> wrote:
> Use git_config_get_string instead of git_config to take advantage of
> the config hash-table api which provides a cleaner control flow.
>
> Signed-off-by: Tanay Abhra <tanayabh@gmail.com>
> ---
>  notes.c | 20 ++++++--------------
>  1 file changed, 6 insertions(+), 14 deletions(-)
>
> diff --git a/notes.c b/notes.c
> index 5fe691d..fc92eec 100644
> --- a/notes.c
> +++ b/notes.c
> @@ -961,19 +961,6 @@ void string_list_add_refs_from_colon_sep(struct string_list *list,
>         free(globs_copy);
>  }
>
> -static int notes_display_config(const char *k, const char *v, void *cb)
> -{
> -       int *load_refs = cb;
> -
> -       if (*load_refs && !strcmp(k, "notes.displayref")) {
> -               if (!v)
> -                       config_error_nonbool(k);
> -               string_list_add_refs_by_glob(&display_notes_refs, v);
> -       }
> -
> -       return 0;
> -}
> -
>  const char *default_notes_ref(void)
>  {
>         const char *notes_ref = NULL;
> @@ -1041,6 +1028,7 @@ struct notes_tree **load_notes_trees(struct string_list *refs)
>  void init_display_notes(struct display_notes_opt *opt)
>  {
>         char *display_ref_env;
> +       const char *value;
>         int load_config_refs = 0;
>         display_notes_refs.strdup_strings = 1;
>
> @@ -1058,7 +1046,11 @@ void init_display_notes(struct display_notes_opt *opt)
>                         load_config_refs = 1;
>         }
>
> -       git_config(notes_display_config, &load_config_refs);
> +       if (load_config_refs && !git_config_get_string("notes.displayref", &value)) {
> +               if (!value)
> +                       config_error_nonbool("notes.displayref");
> +               string_list_add_refs_by_glob(&display_notes_refs, value);

Although you correctly diagnose a NULL 'value', you then invoke
string_list_add_refs_by_glob() with that NULL, which will result in a
crash.

This is not a new error. It dates back to 894a9d33 (Support showing
notes from more than one notes tree; 2010-03-12), but your rewrite
should not retain the brokenness. Whether you fix it in this patch or
a lead-in fix-up patch, the fix deserves mention in the commit
message.

> +       }
>
>         if (opt) {
>                 struct string_list_item *item;
> --
> 1.9.0.GIT