Daniel Gröber (dxld) authored Feb 16, 2021 and Marge Bot committed Feb 28, 2021

The CODEOWNERS documentation has this to say on the current matching
behaviour:

> The path definition order is significant: the last pattern matching a
> given path is used to find the code owners.

Take this as an example:

    /rts/        bgamari [...]
    /rts/win32/  Phyx

(I'm omitting the '@' so as to not notification spam everyone)

This means a change in a file under win23 would only have Phyx but not
bgamari as approver. I don't think that's the behaviour we want.

Using "sections" we can get additive behaviour instead, from the docs:

> Additionally, the usual guidance that only the last pattern matching the
> file is applied is expanded such that the last pattern matching for each
> section is applied.

    [RTS]
    /rts/        bgamari [...]

    [WinIO]
    /rts/win32/  Phyx

So now since those entries are in different sections both would be added to
the approvers list.

The sections feature was introduced in Gitlab 13.2, see "Version history"
on [1] we're currently running 18.8 on gitlab.haskell.org, see [2].

[1]: https://docs.gitlab.com/13.8/ee/user/project/code_owners.html#code-owners-sections
[2]: https://gitlab.haskell.org/help