Proposed revised format for JDK commit messages

[Erik Helin]

On 9/17/18 11:18 AM, Alan Bateman wrote:
> On 17/09/2018 05:27, joe darcy wrote:
>> :
>>
>> Comments?
>>
> Joe - can you provide an example for sponsored contributions? I assume 
> the change author will be the sponsor and there will be a Co-authored-by 
> trailer with the contributor email address. I'm just wondering if this 
> will be incorrectly interpreted as being authored by both the sponsor 
> and contributor when the contributor is the sole author.

Hi Alan,

thanks for reading through the proposal and good question! I did think 
about this case, and right now a "Contributed-by" line with a single 
contributor is being translated so that the single contributor becomes 
the sole author (the sponsor is not listed anywhere). When I read 
through a number of commit messages, it seemed to be common practice to 
list both the sponsor and the contributor when the sponsor also has 
contributed to the patch (and not "only" sponsored it). This is also how 
I personally have used "Contributed-by" when sponsoring HotSpot patches.

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).

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.

Please let us know if you have any more questions!
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