Add --cc-trailers option to b4 am

By request, add ability to copy all addresses from the email's "Cc"
header into Cc: trailers, unless they are already mentioned in some
other trailer.

Requested-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Konstantin Ryabitsev <konstantin@linuxfoundation.org>

5 files changed, 33 insertions, 6 deletions

diff --git a/b4/__init__.py b/b4/__init__.py
index 4da197b..86991e3 100644
--- a/b4/__init__.py
+++ b/b4/__init__.py
@@ -483,7 +483,7 @@ class LoreSeries:
         return slug
 
     def save_am_mbox(self, mbx, noaddtrailers=False, covertrailers=False, trailer_order=None, addmysob=False,
-                     addlink=False, linkmask=None, cherrypick=None):
+                     addlink=False, linkmask=None, cherrypick=None, copyccs=False):
 
         usercfg = get_user_config()
         config = get_main_config()
@@ -559,7 +559,7 @@ class LoreSeries:
                 add_trailers = True
                 if noaddtrailers:
                     add_trailers = False
-                msg = lmsg.get_am_message(add_trailers=add_trailers, trailer_order=trailer_order)
+                msg = lmsg.get_am_message(add_trailers=add_trailers, trailer_order=trailer_order, copyccs=copyccs)
                 # Pass a policy that avoids most legacy encoding horrors
                 mbx.add(msg.as_bytes(policy=emlpolicy))
             else:
@@ -1299,10 +1299,29 @@ class LoreMessage:
 
         return githeaders, message, trailers, basement, signature
 
-    def fix_trailers(self, trailer_order=None):
+    def fix_trailers(self, trailer_order=None, copyccs=False):
         bheaders, message, btrailers, basement, signature = LoreMessage.get_body_parts(self.body)
         # Now we add mix-in trailers
         trailers = btrailers + self.followup_trailers
+
+        if copyccs:
+            allccs = email.utils.getaddresses([str(x) for x in self.msg.get_all('cc', [])])
+            # Sort by domain name, then local
+            allccs.sort(key=lambda x: x[1].find('@') > 0 and x[1].split('@')[1] + x[1].split('@')[0] or x[1])
+            for pair in allccs:
+                found = False
+                for ftr in trailers:
+                    if ftr[1].lower().find(pair[1].lower()) >= 0:
+                        # already present
+                        found = True
+                        break
+
+                if not found:
+                    if len(pair[0]):
+                        trailers.append(('Cc', f'{pair[0]} <{pair[1]}>', None))  # noqa
+                    else:
+                        trailers.append(('Cc', pair[1], None))  # noqa
+
         fixtrailers = list()
         if trailer_order is None:
             trailer_order = DEFAULT_TRAILER_ORDER
@@ -1347,9 +1366,9 @@ class LoreMessage:
             self.body += signature
             self.body += '\n'
 
-    def get_am_message(self, add_trailers=True, trailer_order=None):
+    def get_am_message(self, add_trailers=True, trailer_order=None, copyccs=False):
         if add_trailers:
-            self.fix_trailers(trailer_order=trailer_order)
+            self.fix_trailers(trailer_order=trailer_order, copyccs=copyccs)
         am_body = self.body
         am_msg = email.message.EmailMessage()
         am_msg.set_payload(am_body.encode('utf-8'))
diff --git a/b4/command.py b/b4/command.py
index ee865b9..1105a05 100644
--- a/b4/command.py
+++ b/b4/command.py
@@ -112,6 +112,8 @@ def cmd():
     sp_am.add_argument('-3', '--prep-3way', dest='threeway', action='store_true', default=False,
                        help='Prepare for a 3-way merge '
                             '(tries to ensure that all index blobs exist by making a fake commit range)')
+    sp_am.add_argument('--cc-trailers', dest='copyccs', action='store_true', default=False,
+                       help='Copy all Cc\'d addresses into Cc: trailers')
     sp_am.add_argument('--no-cover', dest='nocover', action='store_true', default=False,
                        help='Do not save the cover letter (on by default when using -o -)')
     sp_am.set_defaults(func=cmd_am)
diff --git a/b4/mbox.py b/b4/mbox.py
index 86825f2..e808c58 100644
--- a/b4/mbox.py
+++ b/b4/mbox.py
@@ -114,7 +114,8 @@ def mbox_to_am(mboxfile, cmdargs):
         am_mbx = lser.save_am_mbox(mbx, noaddtrailers=cmdargs.noaddtrailers,
                                    covertrailers=covertrailers, trailer_order=config['trailer-order'],
                                    addmysob=cmdargs.addmysob, addlink=cmdargs.addlink,
-                                   linkmask=config['linkmask'], cherrypick=cherrypick)
+                                   linkmask=config['linkmask'], cherrypick=cherrypick,
+                                   copyccs=cmdargs.copyccs)
     except KeyError:
         sys.exit(1)
 
diff --git a/man/b4.5 b/man/b4.5
index 8da4ef4..350c363 100644
--- a/man/b4.5
+++ b/man/b4.5
@@ -169,6 +169,9 @@ Try to guess the base of the series (if not specified)
 .B \-3\fP,\fB  \-\-prep\-3way
 Prepare for a 3\-way merge (tries to ensure that all index blobs exist by making a fake commit range)
 .TP
+.B \-\-cc\-trailers
+Copy all Cc\(aqd addresses into Cc: trailers, if not already present
+.TP
 .B \-\-no\-cover
 Do not save the cover letter (on by default when using \-o \-)
 .UNINDENT
diff --git a/man/b4.5.rst b/man/b4.5.rst
index b8f8f8b..d1aa251 100644
--- a/man/b4.5.rst
+++ b/man/b4.5.rst
@@ -104,6 +104,8 @@ optional arguments:
                         Try to guess the base of the series (if not specified)
   -3, --prep-3way
                         Prepare for a 3-way merge (tries to ensure that all index blobs exist by making a fake commit range)
+  --cc-trailers
+                        Copy all Cc'd addresses into Cc: trailers, if not already present
   --no-cover
                         Do not save the cover letter (on by default when using -o -)