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Diffstat (limited to 'Mailman/handlers/avoid_duplicates.py')
| -rw-r--r-- | Mailman/handlers/avoid_duplicates.py | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/Mailman/handlers/avoid_duplicates.py b/Mailman/handlers/avoid_duplicates.py new file mode 100644 index 000000000..a652906a9 --- /dev/null +++ b/Mailman/handlers/avoid_duplicates.py @@ -0,0 +1,93 @@ +# Copyright (C) 2002-2007 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.configuration import config + +COMMASPACE = ', ' + + + +def process(mlist, msg, msgdata): + recips = msgdata.get('recips') + # Short circuit + if not recips: + return + # Seed this set with addresses we don't care about dup avoiding. + listaddrs = set((mlist.posting_address, + mlist.bounces_address, + mlist.owner_address, + mlist.request_address)) + explicit_recips = listaddrs.copy() + # Figure out the set of explicit recipients + cc_addresses = {} + for header in ('to', 'cc', 'resent-to', 'resent-cc'): + addrs = getaddresses(msg.get_all(header, [])) + header_addresses = dict((addr, formataddr((name, addr))) + for name, addr in addrs + if addr) + if header == 'cc': + # Yes, it's possible that an address is mentioned in multiple CC + # headers using different names. In that case, the last real name + # will win, but that doesn't seem like such a big deal. Besides, + # how else would you chose? + cc_addresses.update(header_addresses) + # Ignore the list addresses for purposes of dup avoidance. + explicit_recips |= set(header_addresses) + # Now strip out the list addresses + explicit_recips -= listaddrs + if not explicit_recips: + # No one was explicitly addressed, so we can't do any dup collapsing + return + newrecips = set() + for r in recips: + # If this recipient is explicitly addressed... + if r in explicit_recips: + send_duplicate = True + # If the member wants to receive duplicates, or if the recipient + # is not a member at all, they will get a copy. + # header. + member = mlist.members.get_member(r) + if member and not member.receive_list_copy: + 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', set()).add(r) + newrecips.add(r) + elif r in cc_addresses: + del cc_addresses[r] + 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.add(r) + # Set the new list of recipients. XXX recips should always be a set. + msgdata['recips'] = list(newrecips) + # RFC 2822 specifies zero or one CC header + if cc_addresses: + del msg['cc'] + msg['CC'] = COMMASPACE.join(cc_addresses.values()) |