[PATCH] git_range_to_patches: actually add to/cc headers from cover letter to single-commit series

[PATCH] git_range_to_patches: actually add to/cc headers from cover letter to single-commit series

[Quentin Schulz]

The intent of the original code was to copy the Cc and To headers from
the cover letter, previously added with b4 prep --auto-to-cc. However,
those are added in the commit log which means a newline is inserted
between the subject header and the start of the commit log, "breaking"
the mail parsing because the rest is assumed to be the body of the mail.

Since the To: and Cc: lines are assumed to be in-body, and therefore not
parsed by the mail backend, they cannot be fetched with mail.get('To')
since the header isn't actually set.

Instead, let's use the Cc and To fields returned by get_body_parts of
the covermsg into ctrailers list of LoreTrailer and then add the ones
that are supposed to be To or Cc headers to the single-commit patch
headers.

Fixes: 6c215d83473d ("ez: don't send a cover letter for a 1-patch series")
Fixes: c748abf6ad2a ("ez: don't send a cover letter for a 1-patch series") #v0.10.1
Signed-off-by: Quentin Schulz <quentin.schulz@theobroma-systems.com>
---
git_range_to_patches: actually add to/cc headers from cover letter to single-commit series

I remember also having issues with multiple-commits patch series where the to/cc
fields of the cover wouldn't be applied to the rest of the series, but that'll
be another commit/bug report if I find the issue.

Finally, this probably wasn't detected because git-send-email is capable of
adding the Cc: fields in the "snipped" section of a patch (---) even if not in
the headers but not the To: fields.

To: "Kernel.org Tools" <tools@linux.kernel.org>
Cc: Konstantin Ryabitsev <konstantin@linuxfoundation.org>
---
 b4/__init__.py | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/b4/__init__.py b/b4/__init__.py
index f5bbc53..61ae2c5 100644
--- a/b4/__init__.py
+++ b/b4/__init__.py
@@ -2779,13 +2779,11 @@ def git_range_to_patches(gitdir: Optional[str], start: str, end: str,
 
             pbody = LoreMessage.rebuild_message(pheaders, pmessage, ptrailers, newbasement, csignature)
             pmsg.set_payload(pbody, charset='utf-8')
+
             # Add any To: and Cc: headers from the cover_message
-            toh = covermsg.get('To')
-            if toh:
-                pmsg.add_header('To', toh)
-            cch = covermsg.get('Cc')
-            if cch:
-                pmsg.add_header('Cc', cch)
+            for ctrailer in list(ctrailers):
+                if ctrailer.name in ('To', 'Cc'):
+                    pmsg.add_header(ctrailer.name, ctrailer.value)
             startfrom = 0
         else:
             patches.insert(0, (None, covermsg))

---
base-commit: 287477e9e0149b42e444471da9dca629ebacf2e1
change-id: 20221114-prep-format-patch-single-patch-to-cc-2a878158d50b

Best regards,
-- 
Quentin Schulz <quentin.schulz@theobroma-systems.com>