Subject: Re: git am and duplicate signatures

From: Junio C Hamano <[email-masked]>
Date: Tue, 30 Aug 2016 10:37:10 -0700

Joe Perches <[email-masked]> writes:

> (adding lkml)
>
> On Tue, 2016-08-30 at 09:54 -0700, Junio C Hamano wrote:
>> Joe Perches <[email-masked]> writes:
>> > git-am -s will avoid duplicating the last signature
>> > in a patch.
>> > 
>> > But given a developer creates a patch, send it around for
>> > acks/other signoffs, collects signatures and then does
>> > a git am -s on a different branch, this sort of sign-off
>> > chain is possible:
>> > 
>> > 	Signed-off-by: Original Developer <[email-masked]>
>> > 	Acked-by: Random Developer <[email-masked]>
>> > 	Signed-off-by: Original Developer <[email-masked]>
>> Both correct and allowing the earlier one duplicated as long as
>> there is somebody/something else in between is deliberate.
>
> linux-kernel has a script (scripts/checkpatch.pl) that
> looks for duplicate signatures (<foo>-by: [name] <address>)
>
> Should the last Signed-off-by: in the commit log be
> excluded from this check?

That is left for the kernel folks to decide, but excluding only "the
last" does not make much sense to me.  If you look for only "two
consecutive same signatures" and barf, that would be in line with
what we have been shooting for to support the above "original then
random then back to original" example you gave us above.