[PATCH b4] review: use mail domain for review Message-IDs

[Tamir Duberstein <tamird@kernel.org>]

Pass an explicit domain when generating review reply Message-IDs.
This avoids Python deriving the domain from the local hostname,
which can produce unreadable ip6.arpa-based IDs in b4 review.

Add a regression test covering the review mail path.

Signed-off-by: Tamir Duberstein <tamird@kernel.org>
Co-authored-by: Codex <noreply@openai.com>
---
 src/b4/review/_review.py |  6 +++++-
 src/tests/test_review.py | 11 +++++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/src/b4/review/_review.py b/src/b4/review/_review.py
index 87b25b1..46fd165 100644
--- a/src/b4/review/_review.py
+++ b/src/b4/review/_review.py
@@ -1668,7 +1668,11 @@ def _build_review_email(series: Dict[str, Any], patch_meta: Optional[Dict[str, A
     else:
         msg['References'] = f'<{header_info["msgid"]}>'
     msg['Date'] = email.utils.formatdate(localtime=True)
-    msg['Message-Id'] = email.utils.make_msgid()
+    _, _, mid_domain = user_email.rpartition('@')
+    msg['Message-Id'] = email.utils.make_msgid(
+        idstring='b4-review',
+        domain=mid_domain or 'b4',
+    )
 
     return msg
 
diff --git a/src/tests/test_review.py b/src/tests/test_review.py
index bcea452..f9c2d35 100644
--- a/src/tests/test_review.py
+++ b/src/tests/test_review.py
@@ -1237,6 +1237,17 @@ class TestBuildReviewEmailHeaders:
         assert 'reviewer@example.com' in msg['From']
         assert 'Reviewer' in msg['From']
 
+    @mock.patch('b4.get_email_signature', return_value='sig')
+    @mock.patch('b4.get_user_config', return_value={
+        'name': 'Reviewer', 'email': 'reviewer@example.com'})
+    def test_message_id_uses_reviewer_domain(self, _mock_cfg: mock.Mock,
+                                             _mock_sig: mock.Mock) -> None:
+        msg = review._build_review_email(
+            self._make_series(), None, self._make_review(), 'cover', '', None)
+        assert msg is not None
+        assert msg['Message-Id'].endswith('@example.com>')
+        assert '.ip6.arpa' not in msg['Message-Id']
+
 
 # -- Tests for _build_review_email() user-edited To/Cc -----------------------
 

---
base-commit: 0547fc7a21a580b2a6854aaff1776def2761bba4
change-id: 20260310-review-reply-msgid-cddade4c9b4c

Best regards,
--  
Tamir Duberstein <tamird@kernel.org>