Proposed revised format for JDK commit messages

[Erik Helin]

On 09/17/2018 05:03 PM, mark.reinhold at oracle.com wrote:
> 2018/9/17 6:32:59 -0700, erik.helin at oracle.com:
>> ...
>>
>> For an example, please see the patch for JDK-8210724 [0]. The patch was
>> authored (and proposed) by Man Cao on hotspot-gc-dev [1], reviewed by
>> Kim Barrett and Stefan Johansson and sponsored by JC Beyler.
>>
>> Looking at the commit in the hg repository [2] we have exactly the case
>> you are thinking of: Man Cao is listed as the sole contributor on the
>> "Contributed-by" line and jcbeyler is the author. Looking at the
>> translated commit [3] you will see that Man is listed as the author (and
>> JC isn't mentioned at all).
> 
> That seems like a bug.  It’s important to record the sponsorship
> relation, since the sponsor of a changeset is responsible for any
> adverse consequences of that changeset.

There are ways we can record the sponshorship, see my reply further 
down. Just for my understanding: this only applies to contributions from 
persons with the "Participant" role [4]? Persons with role "Author" [5] 
still needs a sponsor but we don't record that sponsorship, right?

>> Please note that the commit author field says
>> "Man Cao <manc at google.com>", but Man seems to have a GitHub account with
>> the manc at google.com email registered to it, so GitHub will display Man's
>> GitHub username "mancao". So, just to be clear, the git repository
>> contains no GitHub usernames.
>>
>> The motivation for this change is that no SCM tooling understands
>> OpenJDK's "Contributed-by" line, so it seemed easier to just let the
>> author field actually denote the author of the patch. This way commands
>> such as e.g. 'git shortlog' will work correctly.
> 
> Does common SCM tooling understand the “Reviewed-by” line?

No, I am not aware of any tooling that understands the "Reviewed-by" line.

> If not, then the argument against keeping the “Contributed-by” line
> for sponsored changes is pretty weak.

What I don't like about recording sponsors as authors is that not only 
does tools not understand the "Contributed-by" line, they will interpret 
the author field incorrectly (the author is just the sponsor, the real 
author is on the "Contributed-by" line).

How about changing whats get recorded for a sponsored commit? We could 
let the author be recorded in the author field and then have a 
"Sponsored-by" line? This way we could also encode the sponshorship for 
commits from a person with role "Author" (the "Author" would of course 
be the author and we would add an "Sponsored-by" line for the sponsor).

With the concept of "Sponsored-by", the commit at [3] would look like:

  8210724: Change the verbosity threshold of logging for [oopstorage,ref]

  Improve logging verbosity levels in oopStorage.cpp

  Reviewed-by: kbarrett, sjohanss
  Sponsored-by: jcbeyler

and the author would be "Man Cao <manc at google.com>".

What do you think? I'm open for suggestions here, my initial goal was 
just to let author mean author :)

Thanks for your feedback!
Erik

[0]: https://bugs.openjdk.java.net/browse/JDK-8210724
[1]: 
http://mail.openjdk.java.net/pipermail/hotspot-gc-dev/2018-September/023256.html
[2]: http://hg.openjdk.java.net/jdk/jdk/rev/43323ced5e40
[3]: 
https://github.com/openjdk/jdk/commit/4e1a13e673e3efe9ad46766160c75ba1b16cfdff
[4]: http://openjdk.java.net/bylaws#participant
[5]: http://openjdk.java.net/bylaws#author