# Copyright (C) 2002-2008 by the Free Software Foundation, Inc.
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
"""If the user wishes it, do not send duplicates of the same message.
This module keeps an in-memory dictionary of Message-ID: and recipient pairs.
If a message with an identical Message-ID: is about to be sent to someone who
has already received a copy, we either drop the message, add a duplicate
warning header, or pass it through, depending on the user's preferences.
"""
from email.Utils import getaddresses, formataddr
from Mailman import mm_cfg
COMMASPACE = ', '
try:
True, False
except NameError:
True = 1
False = 0
def process(mlist, msg, msgdata):
recips = msgdata['recips']
# Short circuit
if not recips:
return
# There is an issue with addresses in To: or Cc: that differ in
# case from the MemberCPAddresses in recips. We can't just
# lower-case everything because we still want CP addresses in
# the final recips list, so we lower case the keys.
# Seed this set with addresses we don't care about dup avoiding
explicit_recips = {}
listaddrs = [mlist.GetListEmail(), mlist.GetBouncesEmail(),
mlist.GetOwnerEmail(), mlist.GetRequestEmail()]
for addr in listaddrs:
explicit_recips[addr.lower()] = True
# Figure out the set of explicit recipients
ccaddrs = {}
for header in ('to', 'cc', 'resent-to', 'resent-cc'):
addrs = getaddresses(msg.get_all(header, []))
if header == 'cc':
for name, addr in addrs:
ccaddrs[addr.lower()] = name, addr
for name, addr in addrs:
if not addr:
continue
# Ignore the list addresses for purposes of dup avoidance
explicit_recips[addr.lower()] = True
# Now strip out the list addresses
for addr in listaddrs:
del explicit_recips[addr.lower()]
if not explicit_recips:
# No one was explicitly addressed, so we can't do any dup collapsing
return
newrecips = []
for r in recips:
# If this recipient is explicitly addressed...
if explicit_recips.has_key(r.lower()):
send_duplicate = True
# If the member wants to receive duplicates, or if the recipient
# is not a member at all, just flag the X-Mailman-Duplicate: yes
# header.
if mlist.isMember(r) and \
mlist.getMemberOption(r, mm_cfg.DontReceiveDuplicates):
send_duplicate = False
# We'll send a duplicate unless the user doesn't wish it. If
# personalization is enabled, the add-dupe-header flag will add a
# X-Mailman-Duplicate: yes header for this user's message.
if send_duplicate:
msgdata.setdefault('add-dup-header', {})[r] = True
newrecips.append(r)
elif ccaddrs.has_key(r.lower()):
del ccaddrs[r.lower()]
else:
# Otherwise, this is the first time they've been in the recips
# list. Add them to the newrecips list and flag them as having
# received this message.
newrecips.append(r)
# Set the new list of recipients
msgdata['recips'] = newrecips
# RFC 2822 specifies zero or one CC header
del msg['cc']
if ccaddrs:
msg['Cc'] = COMMASPACE.join([formataddr(i) for i in ccaddrs.values()])
