[StGit PATCH v2 4/6] stg mail: factor out __update_header

[Alex Chiang <achiang@hp.com>]

Factor __update_header out of __build_address_headers.

Headers like Reply-To, Mail-Reply-To, and Mail-Followup-To are now
handled in __build_extra_headers.

We make this change because in the future, we do not want to call
__build_address_headers if using git send-email but we will always
want to call __build_extra_headers.

Cc: Karl Wiberg <kha@treskal.com>
Signed-off-by: Alex Chiang <achiang@hp.com>
---

 stgit/commands/mail.py |   48 +++++++++++++++++++++++++-----------------------
 1 files changed, 25 insertions(+), 23 deletions(-)

diff --git a/stgit/commands/mail.py b/stgit/commands/mail.py
index edff878..f430a13 100644
--- a/stgit/commands/mail.py
+++ b/stgit/commands/mail.py
@@ -262,25 +262,25 @@ def __send_message(type, tmpl, options, *args):
     out.done()
     return msg_id
 
-def __build_address_headers(msg, options, extra_cc = []):
-    """Build the address headers and check existing headers in the
-    template.
-    """
+def __update_header(msg, header, addr = '', ignore = ()):
     def __addr_pairs(msg, header, extra):
         pairs = email.Utils.getaddresses(msg.get_all(header, []) + extra)
         # remove pairs without an address and resolve the aliases
         return [address_or_alias(p) for p in pairs if p[1]]
 
-    def __update_header(header, addr = '', ignore = ()):
-        addr_pairs = __addr_pairs(msg, header, [addr])
-        del msg[header]
-        # remove the duplicates and filter the addresses
-        addr_dict = dict((addr, email.Utils.formataddr((name, addr)))
-                         for name, addr in addr_pairs if addr not in ignore)
-        if addr_dict:
-            msg[header] = ', '.join(addr_dict.itervalues())
-        return set(addr_dict.iterkeys())
+    addr_pairs = __addr_pairs(msg, header, [addr])
+    del msg[header]
+    # remove the duplicates and filter the addresses
+    addr_dict = dict((addr, email.Utils.formataddr((name, addr)))
+                     for name, addr in addr_pairs if addr not in ignore)
+    if addr_dict:
+        msg[header] = ', '.join(addr_dict.itervalues())
+    return set(addr_dict.iterkeys())
 
+def __build_address_headers(msg, options, extra_cc = []):
+    """Build the address headers and check existing headers in the
+    template.
+    """
     to_addr = ''
     cc_addr = ''
     extra_cc_addr = ''
@@ -300,18 +300,14 @@ def __build_address_headers(msg, options, extra_cc = []):
         bcc_addr = autobcc
 
     # if an address is on a header, ignore it from the rest
-    to_set = __update_header('To', to_addr)
-    cc_set = __update_header('Cc', cc_addr, to_set)
-    bcc_set = __update_header('Bcc', bcc_addr, to_set.union(cc_set))
+    to_set = __update_header(msg, 'To', to_addr)
+    cc_set = __update_header(msg, 'Cc', cc_addr, to_set)
+    bcc_set = __update_header(msg, 'Bcc', bcc_addr, to_set.union(cc_set))
 
     # --auto generated addresses, don't include the sender
-    from_set = __update_header('From')
-    __update_header('Cc', extra_cc_addr, to_set.union(bcc_set).union(from_set))
-
-    # update other address headers
-    __update_header('Reply-To')
-    __update_header('Mail-Reply-To')
-    __update_header('Mail-Followup-To')
+    from_set = __update_header(msg, 'From')
+    __update_header(msg, 'Cc', extra_cc_addr,
+                    to_set.union(bcc_set).union(from_set))
 
 def __get_signers_list(msg):
     """Return the address list generated from signed-off-by and
@@ -349,6 +345,12 @@ def __build_extra_headers(msg, msg_id, ref_id = None):
         msg['References'] = ref_id
     msg['User-Agent'] = 'StGit/%s' % version.version
 
+    # update other address headers
+    __update_header(msg, 'Reply-To')
+    __update_header(msg, 'Mail-Reply-To')
+    __update_header(msg, 'Mail-Followup-To')
+
+
 def __encode_message(msg):
     # 7 or 8 bit encoding
     charset = email.Charset.Charset('utf-8')