[PATCH v4 0/5] docs & checkpatch: allow Closes tags with links

[Matthieu Baerts <matthieu.baerts@tessares.net>]

Since v6.3, checkpatch.pl now complains about the use of "Closes:" tags
followed by a link [1]. It also complains if a "Reported-by:" tag is
followed by a "Closes:" one [2].

As detailed in the first patch, this "Closes:" tag is used for a bit of
time, mainly by DRM and MPTCP subsystems. It is used by some bug
trackers to automate the closure of issues when a patch is accepted.
It is even planned to use this tag with bugzilla.kernel.org [3].

The first patch updates the documentation to explain what is this
"Closes:" tag and how/when to use it. The second patch modifies
checkpatch.pl to stop complaining about it.

The DRM maintainers and their mailing list have been added in Cc as they
are probably interested by these two patches as well.

[1] https://lore.kernel.org/all/3b036087d80b8c0e07a46a1dbaaf4ad0d018f8d5.1674217480.git.linux@leemhuis.info/
[2] https://lore.kernel.org/all/bb5dfd55ea2026303ab2296f4a6df3da7dd64006.1674217480.git.linux@leemhuis.info/
[3] https://lore.kernel.org/linux-doc/20230315181205.f3av7h6owqzzw64p@meerkat.local/

Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
---
Note: After having re-read the comments from the v1, it is still unclear
to me if this "Closes:" can be accepted or not. But because it seems
that the future Bugzilla bot for kernel.org and regzbot would like to
use it as well, I'm sending here new versions. I'm sorry if I
misunderstood the comments from v1. Please tell me if I did.

Changes in v4:
- Patches 1/5, 3/5 and 4/5 have been added to ask using the "Closes" tag
  instead of the "Link" one for any bug reports. (Thorsten)
- The Fixes tags have been removed from patch 4/5. (Joe)
- The "Reported-by being followed by a link tag" check is now only
  looking for the tag, not the URL which is done elsewhere in patch 5/5.
  (Thorsten)
- A new patch has been added to fix a small issues in checkpatch.pl when
  checking if "Reported-by:" tag is on the last line.
- Link to v3: https://lore.kernel.org/r/20230314-doc-checkpatch-closes-tag-v3-0-d1bdcf31c71c@tessares.net

Changes in v3:
- Patch 1/4 now allow using the "Closes" tag with any kind of bug
  reports, as long as the link is public. (Thorsten)
- The former patch 2/2 has been split in two: first to use a list for
  the different "link" tags (Joe). Then to allow the 'Closes' tag.
- A new patch has been added to let checkpatch.pl checking if "Closes"
  and "Links" are used with a URL.
- Link to v2: https://lore.kernel.org/r/20230314-doc-checkpatch-closes-tag-v2-0-f4a417861f6d@tessares.net

Changes in v2:
- The text on patch 1/2 has been reworked thanks to Jon, Bagas and
  Thorsten. See the individual changelog on the patch for more details.
- Private bug trackers and invalid URLs are clearly marked as forbidden
  to avoid being misused. (Linus)
- Rebased on top of Linus' repo.
- Link to v1: https://lore.kernel.org/r/20230314-doc-checkpatch-closes-tag-v1-0-1b83072e9a9a@tessares.net

---
Matthieu Baerts (5):
      docs: process: allow Closes tags with links
      checkpatch: don't print the next line if not defined
      checkpatch: use a list of "link" tags
      checkpatch: allow Closes tags with links
      checkpatch: check for misuse of the link tags

 Documentation/process/5.Posting.rst          | 22 ++++++++++----
 Documentation/process/submitting-patches.rst | 26 +++++++++++------
 scripts/checkpatch.pl                        | 43 ++++++++++++++++++++++------
 3 files changed, 70 insertions(+), 21 deletions(-)
---
base-commit: 7e364e56293bb98cae1b55fd835f5991c4e96e7d
change-id: 20230314-doc-checkpatch-closes-tag-1731b57556b1

Best regards,
-- 
Matthieu Baerts <matthieu.baerts@tessares.net>