Re: [PATCH] builtin-commit.c: Not add duplicate S-o-b when commit

[Junio C Hamano <gitster@pobox.com>]

Jiang Xin <worldhello.net@gmail.com> writes:

> Scan the whole rfc2822 footer for duplicate S-o-b, not just the last
> line of the commit message.
>
> A commit may have multiple S-o-bs, or other tags, such as:
>
>     some commit log...
>
>     Signed-off-by: C O Mitter <committer@example.com>
>     Reported-by: R E Porter <reporter@example.com>
>
> Because the S-o-b is not located at the last line in the above commit,
> when the above commit is amended by the original committer, a
> duplicated S-o-b may appended by accident. New commit log may looks
> like:
>
>     some commit log...
>
>     Signed-off-by: C O Mitter <committer@example.com>
>     Reported-by: R E Porter <reporter@example.com>
>     Signed-off-by: C O Mitter <committer@example.com>
>

After stating the observation like the above, please make it a habit
to say "which is bad because...", if you think it is a bad behaviour
and the patch is about fixing it.

Because a chain of S-o-b is used to record the flow of a patch, it
is entirely normal if developer A writes the patch (she signs it
off), reviewer B picks it up and sends it back with a minor fix-up
to the list, and developer A again picks it up from the list and
forwards it to the uplevel maintainer, in which case you may see
S-o-b by A, then B (it may be S-o-b or something else,
e.g. Reviewed-by) and then S-o-b by A again.

The above observation is correct (a commit log may look like so),
but your untold conclusion (it is a bad thing because there are
S-o-b from the same person twice) is not necessarily correct.