Solving patch series collisions with domains?

[Francois Gouget]

On Thu, 5 Mar 2020, Marvin wrote:
[...]
> === debiant (build log) ===
> 
> error: patch failed: dlls/d3d11/device.c:941
> error: patch failed: dlls/d3d11/state.c:1079
> error: patch failed: dlls/wined3d/device.c:3600
> error: patch failed: include/wine/wined3d.h:2037
> Task: Patch failed to apply

The TestBot mixed up this 5-parts wined3d patch series with the other 
5-parts patch series for qcap / qedit.

One was a v2 and not the other so taking into account the version would 
have avoided the issue in this case (the patch for this should go in 
next monday).

But this could just as well have happened with unversioned patch series:
    [PATCH 1/5] wined3d: ...
vs. [PATCH 1/5] qcap/capturegraph: ...

The subject parsing code extracts a property I have been calling the 
'domain' (for lack of a better term) which is a word that's sometimes 
added in the square brackets. It's usually used to indicate the Git 
repository the patch should go in: [vkd3d 1/2], [tools], etc.

But it could also be used to avoid collisions between patch series: 
where the TestBot identifies patch series based on the (Sender, Version, 
PartCount) tuple, it could add the domain to the mix: (Sender, Domain, 
Version, PartCount).

This would allow sending two patch series with the same number of parts 
without causing a collision:

   [wined3d 1/5] wined3d: ... +  [qcap 1/5] qcap/capturegraph: ...
or [wined3d 1/5] wined3d: ... +  [PATCH 1/5] qcap/capturegraph: ...
or [PATCH 1/5] wined3d: ...   +  [PATCH qcap 1/5] qcap/capturegraph: ...

PATCH can be thrown in to help identify patches, or omitted. It makes no 
difference to the TestBot.

Not using a domain would work just as well in the absence of a 
collision. And if two patch series risk colliding, adding a domain would 
help avoid the collision. The only drawback is one has to anticipate and 
remember to specify the domain before sending the emails.

Would taking the domain make sense? Would it be worth it?

-- 
Francois Gouget <fgouget at codeweavers.com>