[PATCH b4 v2 0/5] b4: Implement BCC support for patch submissions and review

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

This series implements support for sending patch series and review
replies to blind carbon copy (BCC) recipients.

The work is split into four parts:
1. Server-side support in misc/send-receive.py to receive optional BCC
   envelope destinations via the JSON submission payload and deliver
   them over SMTP while enforcing anti-abuse limits (max-client-bcc)
   and public mailing list destination checks (mustdest).
2. Client-side support in b4 to inject series-wide BCC addresses
   directly into envelope recipients (destaddrs) in send_mail() without
   adding or stripping temporary Bcc: headers. This extends BCC
   capability across sending tools (b4 send, b4 review, b4 ty) and
   supports web endpoint submission.
3. Per-message Bcc: header handling in send_mail() and the review/bugs
   TUIs, extracting Bcc: headers into envelope recipients and stripping
   them before signing and sending while rejecting them on the web
   endpoint.
4. Safety guardrails in ez.py to reject Bcc: trailers in patches and
   cover letters so they are never treated as person trailers and
   leaked into public Cc: headers.

---
Changes in v2:
- Added server-side support in misc/send-receive.py for web endpoint
  submissions.
- Handled series-wide BCC addresses directly in send_mail() as envelope
  recipients instead of adding/deleting temporary Bcc: message headers.
- Extended BCC handling to work across all workflows including b4 review
  and b4 bugs, properly extracting and stripping per-message Bcc:
  headers set in TUI dialogs.
- Added explicit guardrails in b4 send to reject Bcc: trailers in
  patches and cover letters to prevent privacy leaks.
- Added BCC recipient preview and count display in the review and bugs
  TUIs.
- Added unit tests in src/tests/test___init__.py and
  src/tests/test_ez.py.
- Link to v1: https://patch.msgid.link/20260307012748.1414702-1-dmitry.torokhov@gmail.com

To: "Kernel.org Tools" <tools@kernel.org>
Cc: Konstantin Ryabitsev <konstantin@linuxfoundation.org>

---
Dmitry Torokhov (5):
      misc/send-receive: support BCC in web submission endpoint
      b4: implement --bcc and send-series-bcc config option
      b4: handle per-message Bcc headers in send_mail and TUIs
      b4: reject Bcc trailers in patches and cover letter
      misc/send-receive: require messages payload to be a list

 docs/config.rst              |  13 +++-
 docs/contributor/send.rst    |  11 +++-
 misc/default.conf            |   2 +
 misc/send-receive.py         |  34 +++++++++-
 src/b4/__init__.py           |  55 +++++++++++++---
 src/b4/bugs/_tui.py          |   8 ++-
 src/b4/command.py            |   3 +
 src/b4/ez.py                 |  89 ++++++++++++++++++-------
 src/b4/review_tui/_common.py |   4 +-
 src/b4/review_tui/_modals.py |  25 ++++++-
 src/tests/test___init__.py   | 154 +++++++++++++++++++++++++++++++++++++++++++
 src/tests/test_ez.py         |  81 +++++++++++++++++++++++
 12 files changed, 437 insertions(+), 42 deletions(-)
---
base-commit: 0dee38458cbaa10a378fda3fcdd15a626fd92f6d
change-id: 20260831-send-series-bcc-9df240d4f397

Thanks.

-- 
Dmitry