Preserve some kinds of signatures, reenable HTDIG option.

Pull upstream change 1629 to fix Launchpad Bug #1551075
<https://bugs.launchpad.net/mailman/+bug/1551075>. This fix improves
preservation of OpenPGP MIME multipart signatures, by not collapsing
a multipart with a single sub-part inside multipart/signed parts.
See the Launchpad bug report for details.

EXPERIMENTAL feature: Reenable HTDIG support by rolling the patch on our
own, and laying down instructions to do so in the Makefile.  Mark Sapiro
no longer maintains the patch.

Bump PORTREVISION to 3.

Note that the upstream maintainer considers another release in a few
weeks' time, and called for help with updating translations.  If you
want to help, see
<http://www.mail-archive.com/mailman-users%40python.org/msg68036.html>

mail/mailman/Makefile

@@ -3,11 +3,12 @@
 
 PORTNAME=	mailman
 DISTVERSION=	2.1.21
-PORTREVISION=	2
+PORTREVISION=	3
 CATEGORIES=	mail
 MASTER_SITES=	GNU \
 		SF/${PORTNAME}/Mailman%202.1%20%28stable%29/${PORTVERSION} \
 		https://launchpad.net/mailman/${DISTVERSION:R}/${DISTVERSION}/+download/
+PATCH_SITES=	LOCAL/mandree
 DIST_SUBDIR=	mailman
 
 PATCH_DIST_STRIP=	-p1
@@ -64,7 +65,7 @@ PORTDOCS=	ACKNOWLEDGMENTS BUGS FAQ INSTALL NEWS README README-I18N.en \
 
 OPTIONS_SINGLE=	MTA
 OPTIONS_SINGLE_MTA=	COURIER EXIM4 OPENSMTPD POSTFIX SENDMAIL
-OPTIONS_DEFINE=	NAMAZU2 NLS DOCS	# HTDIG defunct in 2.1.21
+OPTIONS_DEFINE=	HTDIG NAMAZU2 NLS DOCS
 OPTIONS_DEFAULT=	SENDMAIL
 COURIER_DESC=	for use with courier
 EXIM4_DESC=	for use with exim4
@@ -109,9 +110,13 @@ MAIL_GID?=	_smtpd
 .endif
 
 .if ${PORT_OPTIONS:MHTDIG}
-PATCH_SITES+=	http://www.msapiro.net/mm/
-PATCHFILES+=	index_htdig.patch.2.1.20
 PKGNAMESUFFIX+=	-with-htdig
+# how to create PATCHFILES:
+#X fetch http://bazaar.launchpad.net/~msapiro/mailman/htdig/tarball/1632?start_revid=1632
+#X unpack this tarball, and the original distfile
+#X diff -NEur original-unpack bazaar-unpack | xz --best -c >msapiro-htdig-1632.patch.xz
+#X upload the latter with mode 0644 or similar to freefall's public_distfiles/ directory
+PATCHFILES+=	msapiro-htdig-1632.patch.xz
 RUN_DEPENDS+=	htdig:${PORTSDIR}/textproc/htdig
 PLIST_SUB+=	SUB_HTDIG=""
 .else

mail/mailman/distinfo

@@ -1,4 +1,4 @@
 SHA256 (mailman/mailman-2.1.21.tgz) = fed33a18154deaa4e81a20798c814485ed4b2e5d8b42cf6d3d55867ff4f70843
 SIZE (mailman/mailman-2.1.21.tgz) = 9266286
-SHA256 (mailman/index_htdig.patch.2.1.20) = 6b47c01b3d65b280829adc8d937e0e8b42d175cceb2a5bc7518e46819f960ac2
-SIZE (mailman/index_htdig.patch.2.1.20) = 324328
+SHA256 (mailman/msapiro-htdig-1632.patch.xz) = 241128c0a10a0f4a31d62433de0cbdc7c96673ff5dd1012af70beb7658f9b38c
+SIZE (mailman/msapiro-htdig-1632.patch.xz) = 50956

mail/mailman/files/patch-LP1551075

@@ -0,0 +1,40 @@
+=== modified file 'Mailman/Handlers/MimeDel.py'
+--- Mailman/Handlers/MimeDel.py	2011-04-13 04:13:10 +0000
++++ Mailman/Handlers/MimeDel.py	2016-02-29 06:28:44 +0000
+@@ -1,4 +1,4 @@
+-# Copyright (C) 2002-2011 by the Free Software Foundation, Inc.
++# Copyright (C) 2002-2016 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
+@@ -210,6 +210,11 @@
+     # If we're left with a multipart message with only one sub-part, recast
+     # the message to just the sub-part, but not if the part is message/rfc822
+     # because we don't want to lose the headers.
++    # Also, if this is a multipart/signed part, stop now as the original part
++    # may have had a multipart sub-part with only one sub-sub-part, the sig
++    # may still be valid and going further may break it.  (LP: #1551075)
++    if msg.get_content_type() == 'multipart/signed':
++        return
+     if msg.is_multipart():
+         if (len(msg.get_payload()) == 1 and
+                 msg.get_content_type() <> 'message/rfc822'):
+
+=== modified file 'NEWS'
+--- NEWS	2016-02-28 20:43:02 +0000
++++ NEWS	2016-02-29 06:28:44 +0000
+@@ -5,6 +5,13 @@
+ 
+ Here is a history of user visible changes to Mailman.
+ 
++2.1.22 (xx-xxx-xxxx)
++
++  Bug fixes and other patches
++
++    - Don't collapse multipart with a single sub-part inside multipart/signed
++      parts.  (LP: #1551075)
++
+ 2.1.21 (28-Feb-2016)
+ 
+   New Features
+