Re: [PATCHv6 06/23] notes.h/c: Propagate combine_notes_fn return value to add_note() and beyond

> The combine_notes_fn functions uses a non-zero return value to indicate
> failure. However, this return value was converted to a call to die()
> in note_tree_insert().
>
> Instead, propagate this return value out to add_note(), and return it
> from there to enable the caller to handle errors appropriately.
>
> Existing add_note() callers are updated to die() upon failure, thus
> preserving the current behaviour. The only exceptions are copy_note()
> and notes_cache_put() where we are able to propagate the add_note()
> return value instead.
>
> This patch has been improved by the following contributions:
> - Jonathan Nieder: Future-proof by always checking add_note() return value
> - Jonathan Nieder: Improve clarity of final if-condition in note_tree_insert()
>
> Thanks-to: Jonathan Nieder <jrnieder@gmail.com>
> Signed-off-by: Johan Herland <johan@herland.net>
> ---
>  builtin/notes.c |   11 ++++++-----
>  notes-cache.c   |    3 +--
>  notes.c         |   55 ++++++++++++++++++++++++++++---------------------------
>  notes.h         |   11 ++++++++---
>  4 files changed, 43 insertions(+), 37 deletions(-)
>
> diff --git a/builtin/notes.c b/builtin/notes.c
> index fbc347c..35f6eb6 100644
> --- a/builtin/notes.c
> +++ b/builtin/notes.c
> @@ -573,8 +573,8 @@ static int add(int argc, const char **argv, const char *prefix)
>
>        if (is_null_sha1(new_note))
>                remove_note(t, object);
> -       else
> -               add_note(t, object, new_note, combine_notes_overwrite);
> +       else if (add_note(t, object, new_note, combine_notes_overwrite))
> +               die("confused: combine_notes_overwrite failed");