Merge 'master' into noverlay

46 files changed, 1958 insertions, 13 deletions

diff --git a/test/lisp/gnus/gnus-group-tests.el b/test/lisp/gnus/gnus-group-tests.el
new file mode 100644
index 00000000000..4ae5fea3eb7
--- /dev/null
+++ b/test/lisp/gnus/gnus-group-tests.el
@@ -0,0 +1,52 @@
+;;; gnus-group-tests.el --- Tests for gnus-group.el  -*- lexical-binding: t; -*-
+
+;; Copyright (C) 2021-2022 Free Software Foundation, Inc.
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs 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 3 of the License, or
+;; (at your option) any later version.
+
+;; GNU Emacs 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 GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;;
+
+;;; Code:
+
+(require 'gnus-group)
+(require 'ert)
+
+(ert-deftest gnus-short-group-name ()
+  (map-apply
+   (lambda (input expected)
+     (should (string-equal (gnus-short-group-name input) expected)))
+   '(("nnimap+email@example.com:archives/2020/03" . "email@example:a/2/03")
+     ("nndiary+diary:birthdays" . "diary:birthdays")
+     ("nnimap+email@example.com:test" . "email@example:test")
+     ("nnimap+email@example.com:234" . "email@example:234")
+
+     ;; This is a very aggressive shortening of the left hand side.
+     ("nnimap+email@banana.salesman.example.com:234" . "email@banana:234")
+     ("nntp+some.where.edu:soc.motss" . "some:s.motss")
+     ("nntp+news.gmane.org:gmane.emacs.gnus.general" . "news:g.e.g.general")
+     ("nntp+news.gnus.org:gmane.text.docbook.apps" . "news:g.t.d.apps")
+
+     ;; nnimap groups.
+     ("nnimap+email@example.com:[Invoices]/Bananas" . "email@example:I/Bananas")
+     ("nnimap+email@banana.salesman.example.com:[Invoices]/Bananas"
+      . "email@banana:I/Bananas")
+
+     ;; The "n" from "nnspool" is perhaps not optimal.
+     ("nnspool+alt.binaries.pictures.furniture" . "n.b.p.furniture"))))
+
+;;; gnus-group-tests.el ends here
diff --git a/test/lisp/gnus/gnus-icalendar-tests.el b/test/lisp/gnus/gnus-icalendar-tests.el
new file mode 100644
index 00000000000..348ddf9f056
--- /dev/null
+++ b/test/lisp/gnus/gnus-icalendar-tests.el
@@ -0,0 +1,259 @@
+;;; gnus-icalendar-tests.el --- tests                -*- lexical-binding: t; -*-
+
+;; Copyright (C) 2020-2022 Free Software Foundation, Inc.
+
+;; Author: Jan Tatarik <jan.tatarik@gmail.com>
+;; Keywords:
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs 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 3 of the License, or
+;; (at your option) any later version.
+
+;; GNU Emacs 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 GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;;
+
+;;; Code:
+
+(require 'ert)
+(require 'gnus-icalendar)
+
+
+(defun gnus-icalendar-tests--get-ical-event (ical-string &optional participant)
+  "Return gnus-icalendar event for ICAL-STRING."
+  (let (event)
+    (with-temp-buffer
+      (insert ical-string)
+      (setq event (gnus-icalendar-event-from-buffer (buffer-name) participant)))
+    event))
+
+(ert-deftest gnus-icalendar-parse ()
+  "test"
+  (let ((tz (getenv "TZ"))
+        (event (gnus-icalendar-tests--get-ical-event "\
+BEGIN:VCALENDAR
+PRODID:-//Google Inc//Google Calendar 70.9054//EN
+VERSION:2.0
+CALSCALE:GREGORIAN
+METHOD:REQUEST
+BEGIN:VTIMEZONE
+TZID:America/New_York
+X-LIC-LOCATION:America/New_York
+BEGIN:DAYLIGHT
+TZOFFSETFROM:-0500
+TZOFFSETTO:-0400
+TZNAME:EDT
+DTSTART:19700308T020000
+RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=2SU
+END:DAYLIGHT
+BEGIN:STANDARD
+TZOFFSETFROM:-0400
+TZOFFSETTO:-0500
+TZNAME:EST
+DTSTART:19701101T020000
+RRULE:FREQ=YEARLY;BYMONTH=11;BYDAY=1SU
+END:STANDARD
+END:VTIMEZONE
+BEGIN:VEVENT
+DTSTART;TZID=America/New_York:20201208T090000
+DTEND;TZID=America/New_York:20201208T100000
+DTSTAMP:20200728T182853Z
+ORGANIZER;CN=Company Events:mailto:anoncompany.com_3bm6fh805bme9uoeliqcle1sa
+ g@group.calendar.google.com
+UID:iipdt88slddpeu7hheuu09sfmd@google.com
+X-MICROSOFT-CDO-OWNERAPPTID:-362490173
+RECURRENCE-ID;TZID=America/New_York:20201208T091500
+CREATED:20200309T134939Z
+DESCRIPTION:In this meeting\\, we will cover topics from product and enginee
+ ring presentations and demos to new hire announcements to watching the late
+LAST-MODIFIED:20200728T182852Z
+LOCATION:New York-22-Town Hall Space (250) [Chrome Box]
+SEQUENCE:4
+STATUS:CONFIRMED
+SUMMARY:Townhall | All Company Meeting
+TRANSP:OPAQUE
+END:VEVENT
+END:VCALENDAR
+")))
+
+    (unwind-protect
+        (progn
+          ;; Use this form so as not to rely on system tz database.
+	  ;; Eg hydra.nixos.org.
+          (setenv "TZ" "CET-1CEST,M3.5.0/2,M10.5.0/3")
+          (should (eq (eieio-object-class event) 'gnus-icalendar-event-request))
+          (should (not (gnus-icalendar-event:recurring-p event)))
+          (should (string= (gnus-icalendar-event:start event) "2020-12-08 15:00"))
+          (with-slots (organizer summary description location end-time uid rsvp participation-type) event
+                      (should (string= organizer "anoncompany.com_3bm6fh805bme9uoeliqcle1sag@group.calendar.google.com"))
+                      (should (string= summary "Townhall | All Company Meeting"))
+                      (should (string= description "In this meeting, we will cover topics from product and engineering presentations and demos to new hire announcements to watching the late"))
+                      (should (string= location "New York-22-Town Hall Space (250) [Chrome Box]"))
+                      (should (string= (format-time-string "%Y-%m-%d %H:%M" end-time) "2020-12-08 16:00"))
+                      (should (string= uid "iipdt88slddpeu7hheuu09sfmd@google.com"))
+                      (should (not rsvp))
+                      (should (eq participation-type 'non-participant))))
+      (setenv "TZ" tz))))
+
+(ert-deftest gnus-icalendary-byday ()
+  ""
+  (let ((tz (getenv "TZ"))
+        (event (gnus-icalendar-tests--get-ical-event "\
+BEGIN:VCALENDAR
+PRODID:Zimbra-Calendar-Provider
+VERSION:2.0
+METHOD:REQUEST
+BEGIN:VTIMEZONE
+TZID:America/New_York
+BEGIN:STANDARD
+DTSTART:16010101T020000
+TZOFFSETTO:-0500
+TZOFFSETFROM:-0400
+RRULE:FREQ=YEARLY;WKST=MO;INTERVAL=1;BYMONTH=11;BYDAY=1SU
+TZNAME:EST
+END:STANDARD
+BEGIN:DAYLIGHT
+DTSTART:16010101T020000
+TZOFFSETTO:-0400
+TZOFFSETFROM:-0500
+RRULE:FREQ=YEARLY;WKST=MO;INTERVAL=1;BYMONTH=3;BYDAY=2SU
+TZNAME:EDT
+END:DAYLIGHT
+END:VTIMEZONE
+BEGIN:VEVENT
+UID:903a5415-9067-4f63-b499-1b6205f49c88
+RRULE:FREQ=DAILY;UNTIL=20200825T035959Z;INTERVAL=1;BYDAY=MO,TU,WE,TH,FR
+SUMMARY:appointment every weekday\\, start jul 24\\, 2020\\, end aug 24\\, 2020
+ATTENDEE;CN=Mark Hershberger;ROLE=REQ-PARTICIPANT;PARTSTAT=NEEDS-ACTION;RSVP
+ =TRUE:mailto:hexmode <at> gmail.com
+ORGANIZER;CN=Mark A. Hershberger:mailto:mah <at> nichework.com
+DTSTART;TZID=\"America/New_York\":20200724T090000
+DTEND;TZID=\"America/New_York\":20200724T093000
+STATUS:CONFIRMED
+CLASS:PUBLIC
+X-MICROSOFT-CDO-INTENDEDSTATUS:BUSY
+TRANSP:OPAQUE
+LAST-MODIFIED:20200719T150815Z
+DTSTAMP:20200719T150815Z
+SEQUENCE:0
+DESCRIPTION:The following is a new meeting request:
+BEGIN:VALARM
+ACTION:DISPLAY
+TRIGGER;RELATED=START:-PT5M
+DESCRIPTION:Reminder
+END:VALARM
+END:VEVENT
+END:VCALENDAR" (list "Mark Hershberger"))))
+
+    (unwind-protect
+        (progn
+          ;; Use this form so as not to rely on system tz database.
+	  ;; Eg hydra.nixos.org.
+          (setenv "TZ" "CET-1CEST,M3.5.0/2,M10.5.0/3")
+    (should (eq (eieio-object-class event) 'gnus-icalendar-event-request))
+    (should (gnus-icalendar-event:recurring-p event))
+    (should (string= (gnus-icalendar-event:recurring-interval event) "1"))
+    (should (string= (gnus-icalendar-event:start event) "2020-07-24 15:00"))
+    (with-slots (organizer summary description location end-time uid rsvp participation-type) event
+      (should (string= organizer "mah <at> nichework.com"))
+      (should (string= summary "appointment every weekday, start jul 24, 2020, end aug 24, 2020"))
+      (should (string= description "The following is a new meeting request:"))
+      (should (null location))
+      (should (string= (format-time-string "%Y-%m-%d %H:%M" end-time) "2020-07-24 15:30"))
+      (should (string= uid "903a5415-9067-4f63-b499-1b6205f49c88"))
+      (should rsvp)
+      (should (eq participation-type 'required)))
+    (should (equal (gnus-icalendar-event:recurring-days event) '(1 2 3 4 5)))
+    (should (string= (gnus-icalendar-event:org-timestamp event) "<2020-07-24 15:00-15:30 +1w>
+<2020-07-27 15:00-15:30 +1w>
+<2020-07-28 15:00-15:30 +1w>
+<2020-07-29 15:00-15:30 +1w>
+<2020-07-30 15:00-15:30 +1w>")))
+      (setenv "TZ" tz))))
+
+(ert-deftest gnus-icalendary-weekly-byday ()
+  ""
+  (let ((tz (getenv "TZ"))
+        (event (gnus-icalendar-tests--get-ical-event "\
+BEGIN:VCALENDAR
+PRODID:-//Google Inc//Google Calendar 70.9054//EN
+VERSION:2.0
+CALSCALE:GREGORIAN
+METHOD:REQUEST
+BEGIN:VTIMEZONE
+TZID:Europe/Berlin
+X-LIC-LOCATION:Europe/Berlin
+BEGIN:DAYLIGHT
+TZOFFSETFROM:+0100
+TZOFFSETTO:+0200
+TZNAME:CEST
+DTSTART:19700329T020000
+RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=-1SU
+END:DAYLIGHT
+BEGIN:STANDARD
+TZOFFSETFROM:+0200
+TZOFFSETTO:+0100
+TZNAME:CET
+DTSTART:19701025T030000
+RRULE:FREQ=YEARLY;BYMONTH=10;BYDAY=-1SU
+END:STANDARD
+END:VTIMEZONE
+BEGIN:VEVENT
+DTSTART;TZID=Europe/Berlin:20200915T140000
+DTEND;TZID=Europe/Berlin:20200915T143000
+RRULE:FREQ=WEEKLY;BYDAY=FR,MO,TH,TU,WE
+DTSTAMP:20200915T120627Z
+ORGANIZER;CN=anon@anoncompany.com:mailto:anon@anoncompany.com
+UID:7b6g3m7iftuo90ei4ul00feqn_R20200915T120000@google.com
+ATTENDEE;CUTYPE=INDIVIDUAL;PARTSTAT=ACCEPTED;RSVP=TRUE
+ ;CN=participant@anoncompany.com;X-NUM-GUESTS=0:mailto:participant@anoncompany.com
+CREATED:20200325T095723Z
+DESCRIPTION:Coffee talk
+LAST-MODIFIED:20200915T120623Z
+LOCATION:
+SEQUENCE:0
+STATUS:CONFIRMED
+SUMMARY:Casual coffee talk
+TRANSP:OPAQUE
+END:VEVENT
+END:VCALENDAR" (list "participant@anoncompany.com"))))
+
+    (unwind-protect
+        (progn
+          ;; Use this form so as not to rely on system tz database.
+	  ;; Eg hydra.nixos.org.
+          (setenv "TZ" "CET-1CEST,M3.5.0/2,M10.5.0/3")
+          (should (eq (eieio-object-class event) 'gnus-icalendar-event-request))
+          (should (gnus-icalendar-event:recurring-p event))
+          (should (string= (gnus-icalendar-event:recurring-interval event) "1"))
+          (should (string= (gnus-icalendar-event:start event) "2020-09-15 14:00"))
+          (with-slots (organizer summary description location end-time uid rsvp participation-type) event
+            (should (string= organizer "anon@anoncompany.com"))
+            (should (string= summary "Casual coffee talk"))
+            (should (string= description "Coffee talk"))
+            (should (string= location ""))
+            (should (string= (format-time-string "%Y-%m-%d %H:%M" end-time) "2020-09-15 14:30"))
+            (should (string= uid "7b6g3m7iftuo90ei4ul00feqn_R20200915T120000@google.com"))
+            (should rsvp)
+            (should (eq participation-type 'required)))
+          (should (equal (sort (gnus-icalendar-event:recurring-days event) #'<) '(1 2 3 4 5)))
+          (should (string= (gnus-icalendar-event:org-timestamp event) "<2020-09-15 14:00-14:30 +1w>
+<2020-09-16 14:00-14:30 +1w>
+<2020-09-17 14:00-14:30 +1w>
+<2020-09-18 14:00-14:30 +1w>
+<2020-09-21 14:00-14:30 +1w>")))
+      (setenv "TZ" tz))))
+
+(provide 'gnus-icalendar-tests)
+;;; gnus-icalendar-tests.el ends here
diff --git a/test/lisp/gnus/gnus-search-tests.el b/test/lisp/gnus/gnus-search-tests.el
new file mode 100644
index 00000000000..4a5def97d3c
--- /dev/null
+++ b/test/lisp/gnus/gnus-search-tests.el
@@ -0,0 +1,100 @@
+;;; gnus-search-tests.el --- Tests for Gnus' search routines  -*- lexical-binding: t; -*-
+
+;; Copyright (C) 2017, 2021-2022 Free Software Foundation, Inc.
+
+;; Author: Eric Abrahamsen <eric@ericabrahamsen.net>
+;; Keywords:
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs 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 3 of the License, or
+;; (at your option) any later version.
+
+;; GNU Emacs 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 GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; Tests for the search parsing, search engines, and their
+;; transformations.
+
+;;; Code:
+
+(require 'ert)
+(require 'gnus-search)
+
+(ert-deftest gnus-s-parse ()
+  "Test basic structural parsing."
+  (let ((pairs
+         '(("string" . ("string"))
+           ("from:john" . ((from . "john")))
+           ("here and there" . ("here" and "there"))
+           ("here or there" . ((or "here" "there")))
+           ("here (there or elsewhere)" . ("here" ((or "there" "elsewhere"))))
+           ("here not there" . ("here" (not "there")))
+           ("from:boss or not vacation" . ((or (from . "boss") (not "vacation")))))))
+    (dolist (p pairs)
+      (should (equal (gnus-search-parse-query (car p)) (cdr p))))))
+
+(ert-deftest gnus-s-expand-keyword ()
+  "Test expansion of keywords"
+  (let ((gnus-search-expandable-keys
+         (default-value 'gnus-search-expandable-keys))
+        (pairs
+         '(("su" . "subject")
+           ("sin" . "since")
+           ("body" . "body")
+           ("list-id" . "list-id"))))
+    (dolist (p pairs)
+      (should (equal (gnus-search-query-expand-key (car p))
+                     (cdr p))))
+    (should-error (gnus-search-query-expand-key "s")
+                  :type 'gnus-search-parse-error)))
+
+(ert-deftest gnus-s-parse-date ()
+  "Test parsing of date expressions."
+  (let ((rel-date (encode-time 0 0 0 15 4 2017))
+        (pairs
+         '(("January" . (nil 1 nil))
+           ("2017" . (nil nil 2017))
+           ("15" . (15 nil nil))
+           ("January 15" . (15 1 nil))
+           ("tuesday" . (11 4 2017))
+           ("1d" . (14 4 2017))
+           ("1w" . (8 4 2017)))))
+    (dolist (p pairs)
+      (should (equal (gnus-search-query-parse-date (car p) rel-date)
+                     (cdr p))))))
+
+(ert-deftest gnus-s-delimited-string ()
+  "Test proper functioning of `gnus-search-query-return-string'."
+  (with-temp-buffer
+    (insert "one\ntwo words\nthree \"words with quotes\"\n\"quotes at start\"\n/alternate \"quotes\"/\n(more bits)")
+    (goto-char (point-min))
+    (should (string= (gnus-search-query-return-string)
+                     "one"))
+    (forward-line)
+    (should (string= (gnus-search-query-return-string)
+                     "two"))
+    (forward-line)
+    (should (string= (gnus-search-query-return-string)
+                     "three"))
+    (forward-line)
+    (should (string= (gnus-search-query-return-string "\"")
+                     "\"quotes at start\""))
+    (forward-line)
+    (should (string= (gnus-search-query-return-string "/")
+                     "/alternate \"quotes\"/"))
+    (forward-line)
+    (should (string= (gnus-search-query-return-string ")" t)
+                     "more bits"))))
+
+(provide 'gnus-search-tests)
+;;; gnus-search-tests.el ends here
diff --git a/test/lisp/gnus/gnus-test-headers.el b/test/lisp/gnus/gnus-test-headers.el
new file mode 100644
index 00000000000..730c10f9818
--- /dev/null
+++ b/test/lisp/gnus/gnus-test-headers.el
@@ -0,0 +1,178 @@
+;;; gnus-test-headers.el --- Tests for Gnus header-related functions  -*- lexical-binding: t; -*-
+
+;; Copyright (C) 2018-2022 Free Software Foundation, Inc.
+
+;; Author: Eric Abrahamsen <eric@ericabrahamsen.net>
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs 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 3 of the License, or
+;; (at your option) any later version.
+
+;; GNU Emacs 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 GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; The tests her are for
+
+;;; Code:
+
+(require 'ert)
+(require 'gnus-sum)
+
+(defconst gnus-headers-test-data
+  '([2 "Re: [Emacs-devel] Emacs move" "Dave Love <d.love@dl.ac.uk>"
+       "Thu, 14 Sep 2000 11:10:46 +0100"
+       "<200009141010.LAA26351@djlvig.dl.ac.uk>"
+       "<20000913175943.A26093@sparky.nisa.net>"
+       1882 16 "nnmaildir mails:2"
+       ((To . "Jeff Bailey <jbailey@nisa.net>")
+        (Cc . "emacs-devel@gnu.org, cvs-hackers@gnu.org"))]
+    [3 "Re: [Emacs-devel] Emacs move" "Sam Steingold <sds@gnu.org>"
+       "14 Sep 2000 10:21:56 -0400" "<upum7xddn.fsf@xchange.com>"
+       "<20000913175943.A26093@sparky.nisa.net>"
+       2991 50 "nnmaildir mails:3"
+       ((To . "Jeff Bailey <jbailey@nisa.net>")
+        (Cc . "emacs-devel@gnu.org, cvs-hackers@gnu.org"))]
+    [4 "Re: [Emacs-devel] Emacs move" "Jeff Bailey <jbailey@nisa.net>"
+       "Thu, 14 Sep 2000 09:14:47 -0700"
+       "<20000914091447.G4827@sparky.nisa.net>"
+       "<20000913175943.A26093@sparky.nisa.net> <upum7xddn.fsf@xchange.com>"
+       1780 15 "nnmaildir mails:4"
+       ((To . "sds@gnu.org, Jeff Bailey <jbailey@nisa.net>")
+        (Cc . "emacs-devel@gnu.org, cvs-hackers@gnu.org"))]
+    [5 "Re: [Emacs-devel] Emacs move" "Dave Love <d.love@dl.ac.uk>"
+       "Thu, 14 Sep 2000 18:24:36 +0100"
+       "<200009141724.SAA26807@djlvig.dl.ac.uk>"
+       "<20000913175943.A26093@sparky.nisa.net>"
+       1343 9 "nnmaildir mails:5"
+       ((To . "Jeff Bailey <jbailey@nisa.net>")
+        (Cc . "emacs-devel@gnu.org, cvs-hackers@gnu.org"))]
+    [6 "Re: [Emacs-devel] Emacs move" "Karl Fogel <kfogel@galois.collab.net>"
+       "14 Sep 2000 10:37:35 -0500" "<87em2nyog0.fsf@galois.collab.net>"
+       "<20000913175943.A26093@sparky.nisa.net> <200009141724.SAA26807@djlvig.dl.ac.uk>"
+       3740 124 "nnmaildir mails:6"
+       ((To . "Dave Love <d.love@dl.ac.uk>")
+        (Cc . "Jeff Bailey <jbailey@nisa.net>, emacs-devel@gnu.org, cvs-hackers@gnu.org"))]
+    [7 "Re: [Emacs-devel] Emacs move" "Jeff Bailey <jbailey@nisa.net>"
+       "Thu, 14 Sep 2000 10:55:12 -0700"
+       "<20000914105512.A29291@sparky.nisa.net>"
+       "<20000913175943.A26093@sparky.nisa.net> <200009141724.SAA26807@djlvig.dl.ac.uk> <87em2nyog0.fsf@galois.collab.net>"
+       1687 16 "nnmaildir mails:7"
+       ((To . "kfogel@red-bean.com, Dave Love <d.love@dl.ac.uk>")
+        (Cc . "Jeff Bailey <jbailey@nisa.net>, emacs-devel@gnu.org, cvs-hackers@gnu.org"))]
+    [8 "Re: [Emacs-devel] Emacs move" "John Wiegley <johnw@gnu.org>"
+       "Thu, 14 Sep 2000 12:19:01 -0700"
+       "<200009141919.MAA05085@localhost.localdomain>"
+       "<20000913175943.A26093@sparky.nisa.net>"
+       1978 27 "nnmaildir mails:8"
+       ((To . "emacs-devel@gnu.org"))]
+    [9 "Re: [Emacs-devel] Emacs move"
+       "\"Robert J. Chassell\" <bob@rattlesnake.com>"
+       "Thu, 14 Sep 2000 07:33:15 -0400 (EDT)"
+       "<m13ZXGV-000BCgC@megalith.rattlesnake.com>"
+       "<20000913175943.A26093@sparky.nisa.net>"
+       3046 72 "nnmaildir mails:9"
+       ((To . "jbailey@nisa.net")
+        (Cc . "emacs-devel@gnu.org, cvs-hackers@gnu.org"))]
+    [10 "Re: [Emacs-devel] Emacs move"
+        "wmperry@aventail.com (William M. Perry)"
+        "14 Sep 2000 09:10:25 -0500"
+        "<86g0n3f4j2.fsf@megalith.bp.aventail.com>"
+        "<20000913175943.A26093@sparky.nisa.net> <m13ZXGV-000BCgC@megalith.rattlesnake.com>"
+        3104 44 "nnmaildir mails:10"
+        ((To . "bob@rattlesnake.com")
+         (Cc . "jbailey@nisa.net, emacs-devel@gnu.org, cvs-hackers@gnu.org"))]
+    [11 "Re: [Emacs-devel] Emacs move" "Gerd Moellmann <gerd@gnu.org>"
+        "Thu, 14 Sep 2000 21:51:05 +0200 (CEST)"
+        "<200009141951.VAA06005@gerd.segv.de>"
+        "<20000913175943.A26093@sparky.nisa.net> <m13ZXGV-000BCgC@megalith.rattlesnake.com> <86g0n3f4j2.fsf@megalith.bp.aventail.com>"
+        1884 6 "nnmaildir mails:11"
+        ((To . "wmvperry@aventail.com")
+         (Cc . "bob@rattlesnake.com, jbailey@nisa.net, emacs-devel@gnu.org, cvs-hackers@gnu.org"))]
+    [12 "Re: [Emacs-devel] Emacs move" "Gerd Moellmann <gerd@gnu.org>"
+        "Thu, 14 Sep 2000 21:49:03 +0200 (CEST)"
+        "<200009141949.VAA05998@gerd.segv.de>"
+        "<20000913175943.A26093@sparky.nisa.net> <m13ZXGV-000BCgC@megalith.rattlesnake.com>"
+        2408 24 "nnmaildir mails:12"
+        ((To . "bob@rattlesnake.com")
+         (Cc . "jbailey@nisa.net, emacs-devel@gnu.org, cvs-hackers@gnu.org"))]
+    [13 "Re: [Emacs-devel] Emacs move"
+        "\"Robert J. Chassell\" <bob@rattlesnake.com>"
+        "Thu, 14 Sep 2000 17:50:01 -0400 (EDT)"
+        "<m13ZgtN-000BD3C@megalith.rattlesnake.com>"
+        "<20000913175943.A26093@sparky.nisa.net> <m13ZXGV-000BCgC@megalith.rattlesnake.com> <200009141949.VAA05998@gerd.segv.de>"
+        1968 23 "nnmaildir mails:13"
+        ((To . "gerd@gnu.org")
+         (Cc . "bob@rattlesnake.com, jbailey@nisa.net, emacs-devel@gnu.org, cvs-hackers@gnu.org"))]
+    [14 "Re: [Emacs-devel] Emacs move" "Richard Stallman <rms@gnu.org>"
+        "Fri, 15 Sep 2000 16:28:12 -0600 (MDT)"
+        "<200009152228.QAA20526@wijiji.santafe.edu>"
+        "<20000913175943.A26093@sparky.nisa.net> <m13ZXGV-000BCgC@megalith.rattlesnake.com>"
+        1288 2 "nnmaildir mails:14"
+        ((To . "jbailey@nisa.net, emacs-devel@gnu.org, cvs-hackers@gnu.org"))]
+    [15 "[Emacs-devel] Emacs move" "Jeff Bailey <jbailey@nisa.net>"
+        "Wed, 13 Sep 2000 17:59:43 -0700"
+        "<20000913175943.A26093@sparky.nisa.net>" ""
+        1661 26 "nnmaildir mails:15"
+        ((To . "emacs-devel@gnu.org")
+         (Cc . "cvs-hackers@gnu.org"))]
+    [16 "Re: [Emacs-devel] Emacs move" "Jeff Bailey <jbailey@nisa.net>"
+        "Fri, 15 Sep 2000 22:00:12 -0700"
+        "<20000915220012.A3923@sparky.nisa.net>"
+        "<20000913175943.A26093@sparky.nisa.net> <m13ZXGV-000BCgC@megalith.rattlesnake.com> <200009141949.VAA05998@gerd.segv.de> <m13ZgtN-000BD3C@megalith.rattlesnake.com>"
+        2857 51 "nnmaildir mails:16"
+        ((To . "bob@rattlesnake.com, gerd@gnu.org")
+         (Cc . "jbailey@nisa.net, emacs-devel@gnu.org, cvs-hackers@gnu.org"))])
+  "A pile of headers with potential interdependencies.")
+
+(ert-deftest gnus-headers-make-dependency-table ()
+  (let ((table (gnus-make-hashtable 20))
+        (data (copy-sequence gnus-headers-test-data))
+        ret)
+    (dolist (h data)
+      ;; `gnus-dependencies-add-header' returns nil if it fails to add
+      ;; the header.
+      (should (gnus-dependencies-add-header h table nil)))
+    ;; Pick a value to test.
+    (setq ret (gethash "<m13ZXGV-000BCgC@megalith.rattlesnake.com>"
+                       table))
+    ;; The message has three children.
+    (should (= 3 (length (cdr ret))))
+    ;; The first of those children has one child.
+    (should (= 1 (length (cdr (nth 1 ret)))))))
+
+(ert-deftest gnus-headers-loop-dependencies ()
+  "Intentionally create a reference loop."
+  (let ((table (gnus-make-hashtable 20))
+        (data (copy-sequence gnus-headers-test-data))
+        (parent-id "<200009141724.SAA26807@djlvig.dl.ac.uk>")
+        (child-id "<87em2nyog0.fsf@galois.collab.net>")
+        parent)
+    (dolist (h data)
+      (gnus-dependencies-add-header h table nil))
+
+    (setq parent (gethash parent-id table))
+
+    ;; Put the parent header in the child references of one of its own
+    ;; children.  `gnus-thread-loop-p' only checks if there's a loop
+    ;; between parent and immediate child, not parent and random
+    ;; descendant.  At least, near as I can tell that's the case.
+
+    (push (list (car parent)) (cdr (gethash child-id table)))
+
+    (let ((gnus-newsgroup-dependencies table))
+     (should
+      (= 1                              ; 1 indicates an infloop.
+         (gnus-thread-loop-p (car parent) (cadr parent)))))))
+
+(provide 'gnus-test-headers)
+;;; gnus-test-headers.el ends here
diff --git a/test/lisp/gnus/gnus-tests.el b/test/lisp/gnus/gnus-tests.el
index c2a41d717cf..4c5a6a8191c 100644
--- a/test/lisp/gnus/gnus-tests.el
+++ b/test/lisp/gnus/gnus-tests.el
@@ -1,6 +1,6 @@
-;;; gnus-tests.el --- Wrapper for the Gnus tests
+;;; gnus-tests.el --- Wrapper for the Gnus tests  -*- lexical-binding:t -*-
 
-;; Copyright (C) 2011-2017 Free Software Foundation, Inc.
+;; Copyright (C) 2011-2022 Free Software Foundation, Inc.
 
 ;; Author: Teodor Zlatanov <tzz@lifelogs.com>
 
@@ -26,8 +26,6 @@
 
 ;;; Code:
 ;; registry.el is required by gnus-registry.el but this way we're explicit.
-(eval-when-compile (require 'cl))
-
 (require 'registry)
 (require 'gnus-registry)
 
diff --git a/test/lisp/gnus/gnus-util-tests.el b/test/lisp/gnus/gnus-util-tests.el
new file mode 100644
index 00000000000..464567061f6
--- /dev/null
+++ b/test/lisp/gnus/gnus-util-tests.el
@@ -0,0 +1,135 @@
+;;; gnus-util-tests.el --- Selectived tests only.  -*- lexical-binding:t -*-
+;; Copyright (C) 2015-2022 Free Software Foundation, Inc.
+
+;; Author: Jens Lechtenbörger <jens.lechtenboerger@fsfe.org>
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs 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 3 of the License, or
+;; (at your option) any later version.
+
+;; GNU Emacs 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 GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;;; Code:
+
+(require 'ert)
+(require 'gnus-util)
+
+(ert-deftest gnus-string> ()
+  ;; Failure paths
+  (should-error (gnus-string> "" 1)
+                :type 'wrong-type-argument)
+  (should-error (gnus-string> "")
+                :type 'wrong-number-of-arguments)
+
+  ;; String tests
+  (should (gnus-string> "def" "abc"))
+  (should (gnus-string> 'def 'abc))
+  (should (gnus-string> "abc" "DEF"))
+  (should (gnus-string> "abc" 'DEF))
+  (should (gnus-string> "αβγ" "abc"))
+  (should (gnus-string> "�בג" "αβγ"))
+  (should (gnus-string> nil ""))
+  (should (gnus-string> "abc" ""))
+  (should (gnus-string> "abc" "ab"))
+  (should-not (gnus-string> "abc" "abc"))
+  (should-not (gnus-string> "abc" "def"))
+  (should-not (gnus-string> "DEF" "abc"))
+  (should-not (gnus-string> 'DEF "abc"))
+  (should-not (gnus-string> "123" "abc"))
+  (should-not (gnus-string> "" "")))
+
+(ert-deftest gnus-string< ()
+  ;; Failure paths
+  (should-error (gnus-string< "" 1)
+                :type 'wrong-type-argument)
+  (should-error (gnus-string< "")
+                :type 'wrong-number-of-arguments)
+
+  ;; String tests
+  (setq case-fold-search nil)
+  (should (gnus-string< "abc" "def"))
+  (should (gnus-string< 'abc 'def))
+  (should (gnus-string< "DEF" "abc"))
+  (should (gnus-string< "DEF" 'abc))
+  (should (gnus-string< "abc" "αβγ"))
+  (should (gnus-string< "αβγ" "�בג"))
+  (should (gnus-string< "" nil))
+  (should (gnus-string< "" "abc"))
+  (should (gnus-string< "ab" "abc"))
+  (should-not (gnus-string< "abc" "abc"))
+  (should-not (gnus-string< "def" "abc"))
+  (should-not (gnus-string< "abc" "DEF"))
+  (should-not (gnus-string< "abc" 'DEF))
+  (should-not (gnus-string< "abc" "123"))
+  (should-not (gnus-string< "" ""))
+
+  ;; gnus-string< checks case-fold-search
+  (setq case-fold-search t)
+  (should (gnus-string< "abc" "DEF"))
+  (should (gnus-string< "abc" 'GHI))
+  (should (gnus-string< 'abc "DEF"))
+  (should (gnus-string< 'GHI 'JKL))
+  (should (gnus-string< "abc" "ΑΒΓ"))
+  (should-not (gnus-string< "ABC" "abc"))
+  (should-not (gnus-string< "def" "ABC")))
+
+(ert-deftest gnus-subsetp ()
+  ;; False for non-lists.
+  (should-not (gnus-subsetp "1" "1"))
+  (should-not (gnus-subsetp "1" '("1")))
+  (should-not (gnus-subsetp '("1") "1"))
+
+  ;; Real tests.
+  (should (gnus-subsetp '() '()))
+  (should (gnus-subsetp '() '("1")))
+  (should (gnus-subsetp '("1") '("1")))
+  (should (gnus-subsetp '(42) '("1" 42)))
+  (should (gnus-subsetp '(42) '(42 "1")))
+  (should (gnus-subsetp '(42) '("1" 42 2)))
+  (should-not (gnus-subsetp '("1") '()))
+  (should-not (gnus-subsetp '("1") '(2)))
+  (should-not (gnus-subsetp '("1" 2) '(2)))
+  (should-not (gnus-subsetp '(2 "1") '(2)))
+  (should-not (gnus-subsetp '("1" 2) '(2 3)))
+
+  ;; Duplicates don't matter for sets.
+  (should (gnus-subsetp '("1" "1") '("1")))
+  (should (gnus-subsetp '("1" 2 "1") '(2 "1")))
+  (should (gnus-subsetp '("1" 2 "1") '(2 "1" "1" 2)))
+  (should-not (gnus-subsetp '("1" 2 "1" 3) '(2 "1" "1" 2))))
+
+(ert-deftest gnus-setdiff ()
+  ;; False for non-lists.
+  (should-not (gnus-setdiff "1" "1"))
+  (should-not (gnus-setdiff "1" '()))
+  (should-not (gnus-setdiff '() "1"))
+
+  ;; Real tests.
+  (should-not (gnus-setdiff '() '()))
+  (should-not (gnus-setdiff '() '("1")))
+  (should-not (gnus-setdiff '("1") '("1")))
+  (should (equal '("1") (gnus-setdiff '("1") '())))
+  (should (equal '("1") (gnus-setdiff '("1") '(2))))
+  (should (equal '("1") (gnus-setdiff '("1" 2) '(2))))
+  (should (equal '("1") (gnus-setdiff '("1" 2 3) '(3 2))))
+  (should (equal '("1") (gnus-setdiff '(2 "1" 3) '(3 2))))
+  (should (equal '("1") (gnus-setdiff '(2 3 "1") '(3 2))))
+  (should (equal '(2 "1") (gnus-setdiff '(2 3 "1") '(3))))
+
+  ;; Duplicates aren't touched for sets if they are not removed.
+  (should-not (gnus-setdiff '("1" "1") '("1")))
+  (should (equal '("1") (gnus-setdiff '(2 "1" 2) '(2))))
+  (should (equal '("1" "1") (gnus-setdiff '(2 "1" 2 "1") '(2)))))
+
+;;; gnus-util-tests.el ends here
diff --git a/test/lisp/gnus/message-tests.el b/test/lisp/gnus/message-tests.el
index f905ba3e263..a724428ecb4 100644
--- a/test/lisp/gnus/message-tests.el
+++ b/test/lisp/gnus/message-tests.el
@@ -1,6 +1,6 @@
-;;; message-mode-tests.el --- Tests for message-mode  -*- lexical-binding: t; -*-
+;;; message-tests.el --- Tests for message-mode  -*- lexical-binding: t; -*-
 
-;; Copyright (C) 2015-2017 Free Software Foundation, Inc.
+;; Copyright (C) 2015-2022 Free Software Foundation, Inc.
 
 ;; Author: João Távora <joaotavora@gmail.com>
 
@@ -29,6 +29,8 @@
 (require 'ert)
 (require 'ert-x)
 
+(require 'cl-lib)
+
 (ert-deftest message-mode-propertize ()
   (with-temp-buffer
     (unwind-protect
@@ -45,14 +47,10 @@
           (setq-local parse-sexp-lookup-properties t)
           (backward-sexp)
           (should (string= "here's an opener "
-                           (buffer-substring-no-properties
-                            (line-beginning-position)
-                            (point))))
+                           (buffer-substring-no-properties (pos-bol) (point))))
           (forward-sexp)
           (should (string= "and here's a closer )"
-                           (buffer-substring-no-properties
-                            (line-beginning-position)
-                            (point)))))
+                           (buffer-substring-no-properties (pos-bol) (point)))))
       (set-buffer-modified-p nil))))
 
 
@@ -97,7 +95,90 @@
         (should (string= stripped-was
                          (message-strip-subject-trailing-was with-was)))))))
 
+(ert-deftest message-all-recipients ()
+  (ert-with-test-buffer (:name "message")
+    (insert "To: Person 1 <p1@p1.org>, Person 2 <p2@p2.org>\n")
+    (insert "Cc: Person 3 <p3@p3.org>, Person 4 <p4@p4.org>\n")
+    (insert "Bcc: Person 5 <p5@p5.org>, Person 6 <p6@p6.org>\n")
+    (should (equal (message-all-recipients)
+                   '(("Person 1" "p1@p1.org")
+                     ("Person 2" "p2@p2.org")
+                     ("Person 3" "p3@p3.org")
+                     ("Person 4" "p4@p4.org")
+                     ("Person 5" "p5@p5.org")
+                     ("Person 6" "p6@p6.org"))))))
+
+(ert-deftest message-all-epg-keys-available-p ()
+  (skip-unless (epg-check-configuration (epg-find-configuration 'OpenPGP)))
+  (let ((person1 '("Person 1" "p1@p1.org"))
+        (person2 '("Person 2" "p2@p2.org"))
+        (person3 '("Person 3" "p3@p3.org"))
+        (recipients nil)
+        (keyring '("p1@p1.org" "p2@p2.org")))
+    (cl-letf (((symbol-function 'epg-list-keys)
+               (lambda (_ email) (cl-find email keyring :test #'string=)))
+              ((symbol-function 'message-all-recipients)
+               (lambda () recipients)))
+
+      (setq recipients (list))
+      (should (message-all-epg-keys-available-p))
+
+      (setq recipients (list person1))
+      (should (message-all-epg-keys-available-p))
+
+      (setq recipients (list person1 person2))
+      (should (message-all-epg-keys-available-p))
+
+      (setq recipients (list person3))
+      (should-not (message-all-epg-keys-available-p))
+
+      (setq recipients (list person1 person3))
+      (should-not (message-all-epg-keys-available-p))
+
+      (setq recipients (list person3 person1))
+      (should-not (message-all-epg-keys-available-p))
+
+      (setq recipients (list person1 person2 person3))
+      (should-not (message-all-epg-keys-available-p)))))
+
+(ert-deftest message-alter-repeat-address ()
+  (should (equal (message--alter-repeat-address
+                  "Lars Ingebrigtsen <larsi@gnus.org>")
+                 "Lars Ingebrigtsen <larsi@gnus.org>"))
+
+  (should (equal (message--alter-repeat-address
+                      "\"larsi@gnus.org\" <larsi@gnus.org>")
+                     "larsi@gnus.org")))
+
+(ert-deftest message-replace-header ()
+  (with-temp-buffer
+    (save-excursion
+      (insert "From: dang@gnus.org
+To: user1,
+    user2
+Cc: user3,
+    user4
+--text follows this line--
+Hello.
+"))
+    (save-excursion
+      (message-replace-header "From" "ding@gnus.org")
+      (should (cl-search "ding" (message-field-value "From"))))
+    (save-excursion
+      (message-replace-header "From" "dong@gnus.org" "To")
+      (should (cl-search "dong" (message-field-value "From")))
+      (should (re-search-forward "From:"))
+      (should-error (re-search-forward "To:"))
+      (should (re-search-forward "Cc:")))
+    (save-excursion
+      (message-replace-header "From" "dang@gnus.org" (split-string "To Cc"))
+      (should (cl-search "dang" (message-field-value "From")))
+      (should (re-search-forward "From:"))
+      (should-error (re-search-forward "To:"))
+      ;; That this isn't so is probably a bug from 1997.
+      ;; (should-error (re-search-forward "Cc:"))
+      )))
 
 (provide 'message-mode-tests)
 
-;;; message-mode-tests.el ends here
+;;; message-tests.el ends here
diff --git a/test/lisp/gnus/mm-decode-resources/8bit-multipart.bin b/test/lisp/gnus/mm-decode-resources/8bit-multipart.bin
new file mode 100644
index 00000000000..0b193a27234
--- /dev/null
+++ b/test/lisp/gnus/mm-decode-resources/8bit-multipart.bin
@@ -0,0 +1,20 @@
+From: example <example@example.org>

+To: example <example@example.org>

+Content-Type: multipart/alternative; boundary="===============2877195075946974246=="

+Date: Thu, 29 Oct 2020 14:47:55 +0100

+MIME-Version: 1.0

+Subject: test

+

+--===============2877195075946974246==

+Content-Type: text/plain; charset="utf-8"

+Content-Transfer-Encoding: 8bit

+

+ääää

+

+--===============2877195075946974246==

+Content-Type: text/html; charset="utf-8"

+Content-Transfer-Encoding: 8bit

+

+<!doctype html><html><head><meta http-equiv="content-type" content="text/html; charset=UTF-8"></head><body>ääää</body></html>

+

+--===============2877195075946974246==--

diff --git a/test/lisp/gnus/mm-decode-resources/win1252-multipart.bin b/test/lisp/gnus/mm-decode-resources/win1252-multipart.bin
new file mode 100644
index 00000000000..d3c5026dcce
--- /dev/null
+++ b/test/lisp/gnus/mm-decode-resources/win1252-multipart.bin
@@ -0,0 +1,44 @@
+To: example <example@example.org>
+From: example <example@example.org>
+Date: Tue, 5 Jan 2021 10:30:34 +0100
+MIME-Version: 1.0
+Content-Type: multipart/mixed; boundary="------------FB569A4368539497CC91D1DC"
+Content-Language: fr
+Subject: test
+
+--------------FB569A4368539497CC91D1DC
+Content-Type: multipart/alternative;
+ boundary="------------61C81A7DC7592E4C6F856A85"
+
+
+--------------61C81A7DC7592E4C6F856A85
+Content-Type: text/plain; charset=windows-1252; format=flowed
+Content-Transfer-Encoding: 8bit
+
+déjŕ raté
+
+--------------61C81A7DC7592E4C6F856A85
+Content-Type: text/html; charset=windows-1252
+Content-Transfer-Encoding: 8bit
+
+<html>
+  <head>
+    <meta http-equiv="content-type" content="text/html; charset=windows-1252">
+  </head>
+  <body>
+    déjŕ raté
+  </body>
+</html>
+
+--------------61C81A7DC7592E4C6F856A85--
+
+--------------FB569A4368539497CC91D1DC
+Content-Type: text/plain; charset="us-ascii"
+MIME-Version: 1.0
+Content-Transfer-Encoding: 7bit
+Content-Disposition: inline
+
+mailing list signature
+
+--------------FB569A4368539497CC91D1DC--
+
diff --git a/test/lisp/gnus/mm-decode-tests.el b/test/lisp/gnus/mm-decode-tests.el
new file mode 100644
index 00000000000..5f39a32b0de
--- /dev/null
+++ b/test/lisp/gnus/mm-decode-tests.el
@@ -0,0 +1,102 @@
+;;; mm-decode-tests.el ---  -*- lexical-binding:t -*-
+
+;; Copyright (C) 2021-2022 Free Software Foundation, Inc.
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs 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 3 of the License, or
+;; (at your option) any later version.
+
+;; GNU Emacs 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 GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;;; Code:
+
+(require 'ert)
+(require 'ert-x)
+(require 'mm-decode)
+
+(ert-deftest test-mm-dissect-buffer ()
+  (with-temp-buffer
+    (set-buffer-multibyte nil)
+    (insert-file-contents-literally (ert-resource-file "8bit-multipart.bin"))
+    (while (search-forward "\r\n" nil t)
+      (replace-match "\n"))
+    (let ((handle (mm-dissect-buffer)))
+      (should (equal (mm-handle-media-type handle) "multipart/alternative"))
+      ;; Skip multipart type.
+      (pop handle)
+      (let ((part (pop handle)))
+        (should (equal (mm-handle-media-type part) "text/plain"))
+        (should (eq (mm-handle-encoding part) '8bit))
+        (with-current-buffer (mm-handle-buffer part)
+          (should (equal (decode-coding-string
+                          (buffer-string)
+                          (intern (mail-content-type-get (mm-handle-type part)
+                                                         'charset)))
+                         "ääää\n"))))
+      (let ((part (pop handle)))
+        (should (equal (mm-handle-media-type part) "text/html"))
+        (should (eq (mm-handle-encoding part) '8bit))
+        (with-current-buffer (mm-handle-buffer part)
+          (should (equal (decode-coding-string
+                          (buffer-string)
+                          (intern (mail-content-type-get (mm-handle-type part)
+                                                         'charset)))
+                         "<!doctype html><html><head><meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\"></head><body>ääää</body></html>\n")))))))
+
+(ert-deftest test-mm-with-part-unibyte ()
+  (with-temp-buffer
+    (set-buffer-multibyte nil)
+    (insert-file-contents-literally (ert-resource-file "8bit-multipart.bin"))
+    (while (search-forward "\r\n" nil t)
+      (replace-match "\n"))
+    (let ((handle (mm-dissect-buffer)))
+      (pop handle)
+      (let ((part (pop handle)))
+        (should (equal (decode-coding-string
+                        (mm-with-part part
+                          (buffer-string))
+                        (intern (mail-content-type-get (mm-handle-type part)
+                                                       'charset)))
+                       "ääää\n"))))))
+
+(ert-deftest test-mm-dissect-buffer-win1252 ()
+  (with-temp-buffer
+    (set-buffer-multibyte nil)
+    (insert-file-contents-literally (ert-resource-file "win1252-multipart.bin"))
+    (let ((handle (mm-dissect-buffer)))
+      (should (equal (mm-handle-media-type handle) "multipart/mixed"))
+      ;; Skip multipart type.
+      (pop handle)
+      (setq handle (car handle))
+      (pop handle)
+      (let ((part (pop handle)))
+        (should (equal (mm-handle-media-type part) "text/plain"))
+        (should (eq (mm-handle-encoding part) '8bit))
+        (with-current-buffer (mm-handle-buffer part)
+          (should (equal (decode-coding-string
+                          (buffer-string)
+                          (intern (mail-content-type-get (mm-handle-type part)
+                                                         'charset)))
+                         "déjà raté\n"))))
+      (let ((part (pop handle)))
+        (should (equal (mm-handle-media-type part) "text/html"))
+        (should (eq (mm-handle-encoding part) '8bit))
+        (with-current-buffer (mm-handle-buffer part)
+          (should (equal (decode-coding-string
+                          (buffer-string)
+                          (intern (mail-content-type-get (mm-handle-type part)
+                                                         'charset)))
+                         "<html>\n  <head>\n    <meta http-equiv=\"content-type\" content=\"text/html; charset=windows-1252\">\n  </head>\n  <body>\n    déjà raté\n  </body>\n</html>\n")))))))
+
+;;; mm-decode-tests.el ends here
diff --git a/test/lisp/gnus/mml-sec-resources/.gpg-v21-migrated b/test/lisp/gnus/mml-sec-resources/.gpg-v21-migrated
new file mode 100644
index 00000000000..e69de29bb2d
--- /dev/null
+++ b/test/lisp/gnus/mml-sec-resources/.gpg-v21-migrated
diff --git a/test/lisp/gnus/mml-sec-resources/gpg-agent.conf b/test/lisp/gnus/mml-sec-resources/gpg-agent.conf
new file mode 100644
index 00000000000..20192990caf
--- /dev/null
+++ b/test/lisp/gnus/mml-sec-resources/gpg-agent.conf
@@ -0,0 +1,5 @@
+# pinentry-program /usr/bin/pinentry-gtk-2
+
+# verbose
+# log-file /tmp/gpg-agent.log
+# debug-all
diff --git a/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/02089CDDC6DFE93B8EA10D9E876F983E61FEC476.key b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/02089CDDC6DFE93B8EA10D9E876F983E61FEC476.key
new file mode 100644
index 00000000000..58fd0b5edbc
--- /dev/null
+++ b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/02089CDDC6DFE93B8EA10D9E876F983E61FEC476.key
diff --git a/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/171B444DE92BEF997229000D9784118A94EEC1C9.key b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/171B444DE92BEF997229000D9784118A94EEC1C9.key
new file mode 100644
index 00000000000..62f4ab25a69
--- /dev/null
+++ b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/171B444DE92BEF997229000D9784118A94EEC1C9.key
diff --git a/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/19FFEBC04DF3E037E16F6A4474DCB7984406975D.key b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/19FFEBC04DF3E037E16F6A4474DCB7984406975D.key
new file mode 100644
index 00000000000..2a8ce135fb2
--- /dev/null
+++ b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/19FFEBC04DF3E037E16F6A4474DCB7984406975D.key
diff --git a/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/1E36D27DF9DAB96302D35268DADC5CE73EF45A2A.key b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/1E36D27DF9DAB96302D35268DADC5CE73EF45A2A.key
new file mode 100644
index 00000000000..9f8de71c5e2
--- /dev/null
+++ b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/1E36D27DF9DAB96302D35268DADC5CE73EF45A2A.key
diff --git a/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/293109315BE584AB2EFEFCFCAD64666221D8B36C.key b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/293109315BE584AB2EFEFCFCAD64666221D8B36C.key
new file mode 100644
index 00000000000..6e4a4e548fd
--- /dev/null
+++ b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/293109315BE584AB2EFEFCFCAD64666221D8B36C.key
diff --git a/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/335689599E1C0F66D73ADCF51E03EE36C97D121F.key b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/335689599E1C0F66D73ADCF51E03EE36C97D121F.key
new file mode 100644
index 00000000000..cff58edaa89
--- /dev/null
+++ b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/335689599E1C0F66D73ADCF51E03EE36C97D121F.key
diff --git a/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/40BF94E540E3726CB150A1ADF7C1B514444B3FA6.key b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/40BF94E540E3726CB150A1ADF7C1B514444B3FA6.key
new file mode 100644
index 00000000000..14af8662f79
--- /dev/null
+++ b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/40BF94E540E3726CB150A1ADF7C1B514444B3FA6.key
diff --git a/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/515D4637EFC6C09DB1F78BE8C2F2A3D63E7756C3.key b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/515D4637EFC6C09DB1F78BE8C2F2A3D63E7756C3.key
new file mode 100644
index 00000000000..207a7237d3a
--- /dev/null
+++ b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/515D4637EFC6C09DB1F78BE8C2F2A3D63E7756C3.key
diff --git a/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/5A11B1935C46D0B227A73978DCA1293A85604F1D.key b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/5A11B1935C46D0B227A73978DCA1293A85604F1D.key
new file mode 100644
index 00000000000..85ca78da04d
--- /dev/null
+++ b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/5A11B1935C46D0B227A73978DCA1293A85604F1D.key
diff --git a/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/62643CEBC7AEBE6817577A34399483700D76BD64.key b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/62643CEBC7AEBE6817577A34399483700D76BD64.key
new file mode 100644
index 00000000000..79f3cd2b841
--- /dev/null
+++ b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/62643CEBC7AEBE6817577A34399483700D76BD64.key
diff --git a/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/680D01F368916A0021C14E3453B27B3C5F900683.key b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/680D01F368916A0021C14E3453B27B3C5F900683.key
new file mode 100644
index 00000000000..776ddf7e9e2
--- /dev/null
+++ b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/680D01F368916A0021C14E3453B27B3C5F900683.key
diff --git a/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/6DF2D9DF7AED06F0524BEB642DF0FB48EFDBDB93.key b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/6DF2D9DF7AED06F0524BEB642DF0FB48EFDBDB93.key
new file mode 100644
index 00000000000..2b464f0ccbe
--- /dev/null
+++ b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/6DF2D9DF7AED06F0524BEB642DF0FB48EFDBDB93.key
diff --git a/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/78C17E134E86E691297F7B719B2F2CDF41976234.key b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/78C17E134E86E691297F7B719B2F2CDF41976234.key
new file mode 100644
index 00000000000..28a07668b21
--- /dev/null
+++ b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/78C17E134E86E691297F7B719B2F2CDF41976234.key
diff --git a/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/7F714F4D9D9676638214991E96D45704E4FFC409.key b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/7F714F4D9D9676638214991E96D45704E4FFC409.key
new file mode 100644
index 00000000000..137659693bd
--- /dev/null
+++ b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/7F714F4D9D9676638214991E96D45704E4FFC409.key
diff --git a/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/854752F5D8090CA36EFBDD79C72BDFF6FA2D1FF0.key b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/854752F5D8090CA36EFBDD79C72BDFF6FA2D1FF0.key
new file mode 100644
index 00000000000..c99824ccd43
--- /dev/null
+++ b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/854752F5D8090CA36EFBDD79C72BDFF6FA2D1FF0.key
diff --git a/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/93FF37C268FDBF0767F5FFDC49409DDAC9388B2C.key b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/93FF37C268FDBF0767F5FFDC49409DDAC9388B2C.key
new file mode 100644
index 00000000000..49c2dc58bd8
--- /dev/null
+++ b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/93FF37C268FDBF0767F5FFDC49409DDAC9388B2C.key
diff --git a/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/A3BA94EAE83509CC90DB1B77B54A51959D8DABEA.key b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/A3BA94EAE83509CC90DB1B77B54A51959D8DABEA.key
new file mode 100644
index 00000000000..ca128408952
--- /dev/null
+++ b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/A3BA94EAE83509CC90DB1B77B54A51959D8DABEA.key
diff --git a/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/A73E9D01F0465B518E8E7D5AD529077AAC1603B4.key b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/A73E9D01F0465B518E8E7D5AD529077AAC1603B4.key
new file mode 100644
index 00000000000..3f14b40927a
--- /dev/null
+++ b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/A73E9D01F0465B518E8E7D5AD529077AAC1603B4.key
diff --git a/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/AE6A24B17A8D0CAF9B7E000AA77F0B41D7BFFFCF.key b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/AE6A24B17A8D0CAF9B7E000AA77F0B41D7BFFFCF.key
new file mode 100644
index 00000000000..06adc06c427
--- /dev/null
+++ b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/AE6A24B17A8D0CAF9B7E000AA77F0B41D7BFFFCF.key
diff --git a/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/C072AF82DCCCB9A7F1B85FFA10B802DC4ED16703.key b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/C072AF82DCCCB9A7F1B85FFA10B802DC4ED16703.key
new file mode 100644
index 00000000000..cf9a60d233b
--- /dev/null
+++ b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/C072AF82DCCCB9A7F1B85FFA10B802DC4ED16703.key
diff --git a/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/C43E1A079B28DFAEBB39CBA01793BDE11EF4B490.key b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/C43E1A079B28DFAEBB39CBA01793BDE11EF4B490.key
new file mode 100644
index 00000000000..0ed35172fe0
--- /dev/null
+++ b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/C43E1A079B28DFAEBB39CBA01793BDE11EF4B490.key
diff --git a/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/C67DAD345455EAD6D51368008FC3A53B8D195B5A.key b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/C67DAD345455EAD6D51368008FC3A53B8D195B5A.key
new file mode 100644
index 00000000000..090059d9e81
--- /dev/null
+++ b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/C67DAD345455EAD6D51368008FC3A53B8D195B5A.key
diff --git a/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/CB5E00CE582C2645D2573FC16B2F14F85A7F47AA.key b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/CB5E00CE582C2645D2573FC16B2F14F85A7F47AA.key
new file mode 100644
index 00000000000..9061f675121
--- /dev/null
+++ b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/CB5E00CE582C2645D2573FC16B2F14F85A7F47AA.key
diff --git a/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/CC68630A06B048F5A91136C162C7A3273E20DE6F.key b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/CC68630A06B048F5A91136C162C7A3273E20DE6F.key
new file mode 100644
index 00000000000..89f6013100d
--- /dev/null
+++ b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/CC68630A06B048F5A91136C162C7A3273E20DE6F.key
diff --git a/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/E7E73903E1BF93481DE0E7C9769D6C31E1863CFF.key b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/E7E73903E1BF93481DE0E7C9769D6C31E1863CFF.key
new file mode 100644
index 00000000000..41dac37574e
--- /dev/null
+++ b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/E7E73903E1BF93481DE0E7C9769D6C31E1863CFF.key
diff --git a/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/F0117468BE801ED4B81972E159A98FDD4814DCEC.key b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/F0117468BE801ED4B81972E159A98FDD4814DCEC.key
new file mode 100644
index 00000000000..5df7b4a5953
--- /dev/null
+++ b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/F0117468BE801ED4B81972E159A98FDD4814DCEC.key
diff --git a/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/F4C5EFD5779BE892CAFD5B721D68DED677C9B151.key b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/F4C5EFD5779BE892CAFD5B721D68DED677C9B151.key
new file mode 100644
index 00000000000..03daf80975b
--- /dev/null
+++ b/test/lisp/gnus/mml-sec-resources/private-keys-v1.d/F4C5EFD5779BE892CAFD5B721D68DED677C9B151.key
diff --git a/test/lisp/gnus/mml-sec-resources/pubring.gpg b/test/lisp/gnus/mml-sec-resources/pubring.gpg
new file mode 100644
index 00000000000..6bd169963df
--- /dev/null
+++ b/test/lisp/gnus/mml-sec-resources/pubring.gpg
diff --git a/test/lisp/gnus/mml-sec-resources/pubring.kbx b/test/lisp/gnus/mml-sec-resources/pubring.kbx
new file mode 100644
index 00000000000..399a0414fd2
--- /dev/null
+++ b/test/lisp/gnus/mml-sec-resources/pubring.kbx
diff --git a/test/lisp/gnus/mml-sec-resources/secring.gpg b/test/lisp/gnus/mml-sec-resources/secring.gpg
new file mode 100644
index 00000000000..b323c072c04
--- /dev/null
+++ b/test/lisp/gnus/mml-sec-resources/secring.gpg
diff --git a/test/lisp/gnus/mml-sec-resources/trustdb.gpg b/test/lisp/gnus/mml-sec-resources/trustdb.gpg
new file mode 100644
index 00000000000..09ebd8db114
--- /dev/null
+++ b/test/lisp/gnus/mml-sec-resources/trustdb.gpg
diff --git a/test/lisp/gnus/mml-sec-resources/trustlist.txt b/test/lisp/gnus/mml-sec-resources/trustlist.txt
new file mode 100644
index 00000000000..f886572d283
--- /dev/null
+++ b/test/lisp/gnus/mml-sec-resources/trustlist.txt
@@ -0,0 +1,26 @@
+# This is the list of trusted keys.  Comment lines, like this one, as
+# well as empty lines are ignored.  Lines have a length limit but this
+# is not a serious limitation as the format of the entries is fixed and
+# checked by gpg-agent.  A non-comment line starts with optional white
+# space, followed by the SHA-1 fingerpint in hex, followed by a flag
+# which may be one of 'P', 'S' or '*' and optionally followed by a list of
+# other flags.  The fingerprint may be prefixed with a '!' to mark the
+# key as not trusted.  You should give the gpg-agent a HUP or run the
+# command "gpgconf --reload gpg-agent" after changing this file.
+
+
+# Include the default trust list
+include-default
+
+
+# CN=No Expiry
+D0:6A:A1:18:65:3C:C3:8E:9D:0C:AF:56:ED:7A:21:35:E1:58:21:77 S relax
+
+# CN=Second Key Pair
+0E:58:22:9B:80:EE:33:95:9F:F7:18:FE:EF:25:40:2B:47:9D:C6:E2 S relax
+
+# CN=No Expiry two UIDs
+D4:CA:78:E1:47:0B:9F:C2:AE:45:D7:84:64:9B:8C:E6:4E:BB:32:0C S relax
+
+# CN=Different subkeys
+4F:96:2A:B7:F4:76:61:6A:78:3D:72:AA:40:35:D5:9B:5F:88:E9:FC S relax
diff --git a/test/lisp/gnus/mml-sec-tests.el b/test/lisp/gnus/mml-sec-tests.el
new file mode 100644
index 00000000000..f308a617645
--- /dev/null
+++ b/test/lisp/gnus/mml-sec-tests.el
@@ -0,0 +1,900 @@
+;;; mml-sec-tests.el --- Tests mml-sec.el, see README-mml-secure.txt.  -*- lexical-binding:t -*-
+
+;; Copyright (C) 2015, 2020-2022 Free Software Foundation, Inc.
+
+;; Author: Jens Lechtenbörger <jens.lechtenboerger@fsfe.org>
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs 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 3 of the License, or
+;; (at your option) any later version.
+
+;; GNU Emacs 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 GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;;; Code:
+
+(require 'ert)
+(require 'ert-x)
+
+(require 'message)
+(require 'epa)
+(require 'epg)
+(require 'mml-sec)
+(require 'gnus-sum)
+
+(defvar with-smime nil
+  "If nil, exclude S/MIME from tests as passphrases need to entered manually.
+Mostly, the empty passphrase is used.  However, the keys for
+ \"No Expiry two UIDs\" have the passphrase \"Passphrase\" (for OpenPGP as well
+ as S/MIME).")
+
+(defun test-conf ()
+  ;; Emacs doesn't have support for finding the name of the PGP agent
+  ;; on MacOS, so disable the checks.
+  (and (not (eq system-type 'darwin))
+       (ignore-errors (epg-find-configuration 'OpenPGP))))
+
+(defun enc-standards ()
+  (if with-smime '(enc-pgp enc-pgp-mime enc-smime)
+    '(enc-pgp enc-pgp-mime)))
+(defun enc-sign-standards ()
+  (if with-smime
+      '(enc-sign-pgp enc-sign-pgp-mime enc-sign-smime)
+    '(enc-sign-pgp enc-sign-pgp-mime)))
+(defun sign-standards ()
+  (if with-smime
+      '(sign-pgp sign-pgp-mime sign-smime)
+    '(sign-pgp sign-pgp-mime)))
+
+(defvar mml-smime-use)
+
+(defun mml-secure-test-fixture (body &optional interactive)
+  "Setup GnuPG home containing test keys and prepare environment for BODY.
+If optional INTERACTIVE is non-nil, allow questions to the user in case of
+key problems.
+This fixture temporarily unsets GPG_AGENT_INFO to enable passphrase tests,
+which will neither work with gpgsm nor GnuPG 2.1 any longer, I guess.
+Actually, I'm not sure why people would want to cache passwords in Emacs
+instead of gpg-agent."
+  (unwind-protect
+      (let ((agent-info (getenv "GPG_AGENT_INFO"))
+	    (gpghome (getenv "GNUPGHOME")))
+	(condition-case error
+            (let ((epg-gpg-home-directory (ert-resource-directory))
+		  (mml-smime-use 'epg)
+		  ;; Create debug output in empty epg-debug-buffer.
+		  (epg-debug t)
+		  (epg-debug-buffer (get-buffer-create " *epg-test*"))
+		  (mml-secure-fail-when-key-problem (not interactive)))
+	      (with-current-buffer epg-debug-buffer
+		(erase-buffer))
+	      ;; Unset GPG_AGENT_INFO to enable passphrase caching inside Emacs.
+	      ;; Just for testing.  Jens does not recommend this for daily use.
+	      (setenv "GPG_AGENT_INFO")
+	      ;; Set GNUPGHOME as gpg-agent started by gpgsm does
+	      ;; not look in the proper places otherwise, see:
+	      ;; https://bugs.gnupg.org/gnupg/issue2126
+	      (setenv "GNUPGHOME" epg-gpg-home-directory)
+              (unwind-protect
+	          (funcall body)
+                (mml-sec-test--kill-gpg-agent)))
+	  (error
+	   (setenv "GPG_AGENT_INFO" agent-info)
+	   (setenv "GNUPGHOME" gpghome)
+	   (signal (car error) (cdr error))))
+	(setenv "GPG_AGENT_INFO" agent-info)
+	(setenv "GNUPGHOME" gpghome))))
+
+(defun mml-secure-test-message-setup (method to from &optional text bcc)
+  "Setup a buffer with MML METHOD, TO, and FROM headers.
+Optionally, a message TEXT and BCC header can be passed."
+  (with-temp-buffer
+    (when bcc (insert (format "Bcc: %s\n" bcc)))
+    (insert (format "To: %s
+From: %s
+Subject: Test
+%s\n" to from mail-header-separator))
+    (if text
+	(insert (format "%s" text))
+      (spook))
+    (cond ((eq method 'enc-pgp-mime)
+	   (mml-secure-message-encrypt-pgpmime 'nosig))
+	  ((eq method 'enc-sign-pgp-mime)
+	   (mml-secure-message-encrypt-pgpmime))
+	  ((eq method 'enc-pgp) (mml-secure-message-encrypt-pgp 'nosig))
+	  ((eq method 'enc-sign-pgp) (mml-secure-message-encrypt-pgp))
+	  ((eq method 'enc-smime) (mml-secure-message-encrypt-smime 'nosig))
+	  ((eq method 'enc-sign-smime) (mml-secure-message-encrypt-smime))
+	  ((eq method 'sign-pgp-mime) (mml-secure-message-sign-pgpmime))
+	  ((eq method 'sign-pgp) (mml-secure-message-sign-pgp))
+	  ((eq method 'sign-smime) (mml-secure-message-sign-smime))
+	  (t (error "Unknown method")))
+    (buffer-string)))
+
+(defun mml-secure-test-mail-fixture (method to from body2
+					    &optional interactive)
+  "Setup buffer encrypted using METHOD for TO from FROM, call BODY2.
+Pass optional INTERACTIVE to mml-secure-test-fixture."
+  (mml-secure-test-fixture
+   (lambda ()
+     (let ((_context (if (memq method '(enc-smime enc-sign-smime sign-smime))
+                         (epg-make-context 'CMS)
+                       (epg-make-context 'OpenPGP)))
+	   ;; Verify and decrypt by default.
+	   (mm-verify-option 'known)
+	   (mm-decrypt-option 'known)
+	   (plaintext "The Magic Words are Squeamish Ossifrage"))
+       (with-temp-buffer
+	 (insert (mml-secure-test-message-setup method to from plaintext))
+	 (message-options-set-recipient)
+	 (message-encode-message-body)
+	 ;; Replace separator line with newline.
+	 (goto-char (point-min))
+	 (re-search-forward
+	  (concat "^" (regexp-quote mail-header-separator) "\n"))
+	 (replace-match "\n")
+	 ;; The following treatment of handles, plainbuf, and multipart
+	 ;; resulted from trial-and-error.
+	 ;; Someone with more knowledge on how to decrypt messages and verify
+	 ;; signatures might know more appropriate functions to invoke
+	 ;; instead.
+	 (let* ((handles (or (mm-dissect-buffer)
+			     (mm-uu-dissect)))
+		(isplain (bufferp (car handles)))
+		(ismultipart (equal (car handles) "multipart/mixed"))
+		(plainbuf (if isplain
+			      (car handles)
+			    (if ismultipart
+				(car (cadadr handles))
+			      (caadr handles))))
+		(decrypted
+		 (with-current-buffer plainbuf (buffer-string)))
+		(gnus-info
+		 (if isplain
+		     nil
+		   (if ismultipart
+		       (or (mm-handle-multipart-ctl-parameter
+			    (cadr handles) 'gnus-details)
+			   (mm-handle-multipart-ctl-parameter
+			    (cadr handles) 'gnus-info))
+		     (mm-handle-multipart-ctl-parameter
+		      handles 'gnus-info)))))
+	   (funcall body2 gnus-info plaintext decrypted)))))
+   interactive))
+
+;; TODO If the variable BODY3 is renamed to BODY, an infinite recursion
+;; occurs.  Emacs bug?
+(defun mml-secure-test-key-fixture (body3)
+  "Customize unique keys for sub@example.org and call BODY3.
+For OpenPGP, we have:
+- 1E6B FA97 3D9E 3103 B77F  D399 C399 9CF1 268D BEA2
+  uid                  Different subkeys <sub@example.org>
+- 1463 2ECA B9E2 2736 9C8D  D97B F7E7 9AB7 AE31 D471
+  uid                  Second Key Pair <sub@example.org>
+
+For S/MIME:
+          ID: 0x479DC6E2
+      Subject: /CN=Second Key Pair
+          aka: sub@example.org
+  fingerprint: 0E:58:22:9B:80:EE:33:95:9F:F7:18:FE:EF:25:40:2B:47:9D:C6:E2
+
+           ID: 0x5F88E9FC
+      Subject: /CN=Different subkeys
+          aka: sub@example.org
+  fingerprint: 4F:96:2A:B7:F4:76:61:6A:78:3D:72:AA:40:35:D5:9B:5F:88:E9:FC
+
+In both cases, the first key is customized for signing and encryption."
+  (mml-secure-test-fixture
+   (lambda ()
+     (let* ((mml-secure-key-preferences
+	     '((OpenPGP (sign) (encrypt)) (CMS (sign) (encrypt))))
+	    (pcontext (epg-make-context 'OpenPGP))
+	    (pkey (epg-list-keys pcontext "C3999CF1268DBEA2"))
+	    (scontext (epg-make-context 'CMS))
+	    (skey (epg-list-keys scontext "0x479DC6E2")))
+       (mml-secure-cust-record-keys pcontext 'encrypt "sub@example.org" pkey)
+       (mml-secure-cust-record-keys pcontext 'sign "sub@example.org" pkey)
+       (mml-secure-cust-record-keys scontext 'encrypt "sub@example.org" skey)
+       (mml-secure-cust-record-keys scontext 'sign "sub@example.org" skey)
+       (funcall body3)))))
+
+(ert-deftest mml-secure-key-checks ()
+  "Test mml-secure-check-user-id and mml-secure-check-sub-key on sample keys."
+  (skip-unless (test-conf))
+  (mml-secure-test-fixture
+   (lambda ()
+     (let* ((context (epg-make-context 'OpenPGP))
+	    (keys1 (epg-list-keys context "expired@example.org"))
+	    (keys2 (epg-list-keys context "no-exp@example.org"))
+	    (keys3 (epg-list-keys context "sub@example.org"))
+	    (keys4 (epg-list-keys context "revoked-uid@example.org"))
+	    (keys5 (epg-list-keys context "disabled@example.org"))
+	    (keys6 (epg-list-keys context "sign@example.org"))
+	    (keys7 (epg-list-keys context "jens.lechtenboerger@fsfe"))
+	    )
+       (should (and (= 1 (length keys1)) (= 1 (length keys2))
+		    (= 2 (length keys3))
+		    (= 1 (length keys4)) (= 1 (length keys5))
+		    ))
+       ;; key1 is expired
+       (should-not (mml-secure-check-user-id (car keys1) "expired@example.org"))
+       (should-not (mml-secure-check-sub-key context (car keys1) 'encrypt))
+       (should-not (mml-secure-check-sub-key context (car keys1) 'sign))
+
+       ;; key2 does not expire, but does not have the UID expired@example.org
+       (should-not (mml-secure-check-user-id (car keys2) "expired@example.org"))
+       (should (mml-secure-check-user-id (car keys2) "no-exp@example.org"))
+       (should (mml-secure-check-sub-key context (car keys2) 'encrypt))
+       (should (mml-secure-check-sub-key context (car keys2) 'sign))
+
+       ;; Two keys exist for sub@example.org.
+       (should (mml-secure-check-user-id (car keys3) "sub@example.org"))
+       (should (mml-secure-check-sub-key context (car keys3) 'encrypt))
+       (should (mml-secure-check-sub-key context (car keys3) 'sign))
+       (should (mml-secure-check-user-id (cadr keys3) "sub@example.org"))
+       (should (mml-secure-check-sub-key context (cadr keys3) 'encrypt))
+       (should (mml-secure-check-sub-key context (cadr keys3) 'sign))
+
+       ;; The UID revoked-uid@example.org is revoked.  The key itself is
+       ;; usable, though (with the UID sub@example.org).
+       (should-not
+	(mml-secure-check-user-id (car keys4) "revoked-uid@example.org"))
+       (should (mml-secure-check-sub-key context (car keys4) 'encrypt))
+       (should (mml-secure-check-sub-key context (car keys4) 'sign))
+       (should (mml-secure-check-user-id (car keys4) "sub@example.org"))
+
+       ;; The next key is disabled and, thus, unusable.
+       (should (mml-secure-check-user-id (car keys5) "disabled@example.org"))
+       (should-not (mml-secure-check-sub-key context (car keys5) 'encrypt))
+       (should-not (mml-secure-check-sub-key context (car keys5) 'sign))
+
+       ;; The next key has multiple subkeys.
+       ;; 42466F0F is valid sign subkey, 501FFD98 is expired
+       (should (mml-secure-check-sub-key context (car keys6) 'sign "42466F0F"))
+       (should-not
+	(mml-secure-check-sub-key context (car keys6) 'sign "501FFD98"))
+       ;; DC7F66E7 is encrypt subkey
+       (should
+	(mml-secure-check-sub-key context (car keys6) 'encrypt "DC7F66E7"))
+       (should-not
+	(mml-secure-check-sub-key context (car keys6) 'sign "DC7F66E7"))
+       (should-not
+	(mml-secure-check-sub-key context (car keys6) 'encrypt "42466F0F"))
+
+       ;; The final key is just a public key.
+       (should (mml-secure-check-sub-key context (car keys7) 'encrypt))
+       (should-not (mml-secure-check-sub-key context (car keys7) 'sign))
+       ))))
+
+(ert-deftest mml-secure-find-usable-keys-1 ()
+  "Make sure that expired and disabled keys and revoked UIDs are not used."
+  (skip-unless (test-conf))
+  (mml-secure-test-fixture
+   (lambda ()
+     (let ((context (epg-make-context 'OpenPGP)))
+       (should-not
+	(mml-secure-find-usable-keys context "expired@example.org" 'encrypt))
+       (should-not
+	(mml-secure-find-usable-keys context "expired@example.org" 'sign))
+
+       (should-not
+	(mml-secure-find-usable-keys context "disabled@example.org" 'encrypt))
+       (should-not
+	(mml-secure-find-usable-keys context "disabled@example.org" 'sign))
+
+       (should-not
+	(mml-secure-find-usable-keys
+	 context "<revoked-uid@example.org>" 'encrypt))
+       (should-not
+	(mml-secure-find-usable-keys
+	 context "<revoked-uid@example.org>" 'sign))
+       ;; Same test without ankles.  Will fail for Ma Gnus v0.14 and earlier.
+       (should-not
+	(mml-secure-find-usable-keys
+	 context "revoked-uid@example.org" 'encrypt))
+
+       ;; Expired key should not be usable.
+       ;; Will fail for Ma Gnus v0.14 and earlier.
+       ;; sign@example.org has the expired subkey 0x501FFD98.
+       (should-not
+	(mml-secure-find-usable-keys context "0x501FFD98" 'sign))
+
+       (should
+	(mml-secure-find-usable-keys context "no-exp@example.org" 'encrypt))
+       (should
+	(mml-secure-find-usable-keys context "no-exp@example.org" 'sign))
+       ))))
+
+(ert-deftest mml-secure-find-usable-keys-2 ()
+  "Test different ways to search for keys."
+  (skip-unless (test-conf))
+  (mml-secure-test-fixture
+   (lambda ()
+     (let ((context (epg-make-context 'OpenPGP)))
+       ;; Plain substring search is not supported.
+       (should
+	(= 0 (length
+	      (mml-secure-find-usable-keys context "No Expiry" 'encrypt))))
+       (should
+	(= 0 (length
+	      (mml-secure-find-usable-keys context "No Expiry" 'sign))))
+
+       ;; Search for e-mail addresses works with and without ankle brackets.
+       (should
+	(= 1 (length (mml-secure-find-usable-keys
+		      context "<no-exp@example.org>" 'encrypt))))
+       (should
+	(= 1 (length (mml-secure-find-usable-keys
+		      context "<no-exp@example.org>" 'sign))))
+       (should
+	(= 1 (length (mml-secure-find-usable-keys
+		      context "no-exp@example.org" 'encrypt))))
+       (should
+	(= 1 (length (mml-secure-find-usable-keys
+		      context "no-exp@example.org" 'sign))))
+
+       ;; Use full UID string.
+       (should
+	(= 1 (length (mml-secure-find-usable-keys
+		      context "No Expiry <no-exp@example.org>" 'encrypt))))
+       (should
+	(= 1 (length (mml-secure-find-usable-keys
+		      context "No Expiry <no-exp@example.org>" 'sign))))
+
+       ;; If just the public key is present, only encryption is possible.
+       ;; Search works with key IDs, with and without prefix "0x".
+       (should
+	(= 1 (length (mml-secure-find-usable-keys
+		      context "A142FD84" 'encrypt))))
+       (should
+	(= 1 (length (mml-secure-find-usable-keys
+		      context "0xA142FD84" 'encrypt))))
+       (should
+	(= 0 (length (mml-secure-find-usable-keys
+		      context "A142FD84" 'sign))))
+       (should
+	(= 0 (length (mml-secure-find-usable-keys
+		      context "0xA142FD84" 'sign))))
+       ))))
+
+(ert-deftest mml-secure-select-preferred-keys-1 ()
+  "If only one key exists for an e-mail address, it is the preferred one."
+  (skip-unless (test-conf))
+  (mml-secure-test-fixture
+   (lambda ()
+     (let ((context (epg-make-context 'OpenPGP)))
+       (should (equal "832F3CC6518D37BC658261B802372A42CA6D40FB"
+		      (mml-secure-fingerprint
+		       (car (mml-secure-select-preferred-keys
+			     context '("no-exp@example.org") 'encrypt)))))))))
+
+(ert-deftest mml-secure-select-preferred-keys-2 ()
+  "If multiple keys exists for an e-mail address, customization is necessary."
+  (skip-unless (test-conf))
+  (mml-secure-test-fixture
+   (lambda ()
+     (let* ((context (epg-make-context 'OpenPGP))
+	    (mml-secure-key-preferences
+	     '((OpenPGP (sign) (encrypt)) (CMS (sign) (encrypt))))
+	    (pref (car (mml-secure-find-usable-keys
+			context "sub@example.org" 'encrypt))))
+       (should-error (mml-secure-select-preferred-keys
+		      context '("sub@example.org") 'encrypt))
+       (mml-secure-cust-record-keys
+	context 'encrypt "sub@example.org" (list pref))
+       (should (mml-secure-select-preferred-keys
+		context '("sub@example.org") 'encrypt))
+       (should-error (mml-secure-select-preferred-keys
+		      context '("sub@example.org") 'sign))
+       (should (mml-secure-select-preferred-keys
+                context '("sub@example.org") 'encrypt))
+       (should
+	(equal (list (mml-secure-fingerprint pref))
+	       (mml-secure-cust-fpr-lookup context 'encrypt "sub@example.org")))
+       (should (mml-secure-cust-remove-keys context 'encrypt "sub@example.org"))
+       (should-error (mml-secure-select-preferred-keys
+                      context '("sub@example.org") 'encrypt))))))
+
+(ert-deftest mml-secure-select-preferred-keys-3 ()
+  "Expired customized keys are removed if multiple keys are available."
+  (skip-unless (test-conf))
+  (mml-secure-test-fixture
+   (lambda ()
+     (let ((context (epg-make-context 'OpenPGP))
+	   (mml-secure-key-preferences
+	    '((OpenPGP (sign) (encrypt)) (CMS (sign) (encrypt)))))
+       ;; sub@example.org has two keys (268DBEA2, AE31D471).
+       ;; Normal preference works.
+       (mml-secure-cust-record-keys
+        context 'encrypt "sub@example.org" (epg-list-keys context "268DBEA2"))
+       (should (mml-secure-select-preferred-keys
+		context '("sub@example.org") 'encrypt))
+       (mml-secure-cust-remove-keys context 'encrypt "sub@example.org")
+
+       ;; Fake preference for expired (unrelated) key CE15FAE7,
+       ;; results in error (and automatic removal of outdated preference).
+       (mml-secure-cust-record-keys
+        context 'encrypt "sub@example.org" (epg-list-keys context "CE15FAE7"))
+       (should-error (mml-secure-select-preferred-keys
+		      context '("sub@example.org") 'encrypt))
+       (should-not
+	(mml-secure-cust-remove-keys context 'encrypt "sub@example.org"))))))
+
+(ert-deftest mml-secure-select-preferred-keys-4 ()
+  "Multiple keys can be recorded per recipient or signature."
+  (skip-unless (test-conf))
+  (skip-unless (ignore-errors (epg-find-configuration 'CMS)))
+  (mml-secure-test-fixture
+   (lambda ()
+     (let ((pcontext (epg-make-context 'OpenPGP))
+	   (scontext (epg-make-context 'CMS))
+	   (pkeys '("1E6BFA973D9E3103B77FD399C3999CF1268DBEA2"
+		    "14632ECAB9E227369C8DD97BF7E79AB7AE31D471"))
+	   (skeys  '("0x5F88E9FC" "0x479DC6E2"))
+	   (mml-secure-key-preferences
+	    '((OpenPGP (sign) (encrypt)) (CMS (sign) (encrypt)))))
+
+       ;; OpenPGP preferences via pcontext
+       (dolist (key pkeys nil)
+	 (mml-secure-cust-record-keys
+	  pcontext 'encrypt "sub@example.org" (epg-list-keys pcontext key))
+	 (mml-secure-cust-record-keys
+	  pcontext 'sign "sub@example.org" (epg-list-keys pcontext key 'secret)))
+       (let ((p-e-fprs (mml-secure-cust-fpr-lookup
+			pcontext 'encrypt "sub@example.org"))
+	     (p-s-fprs (mml-secure-cust-fpr-lookup
+			pcontext 'sign "sub@example.org")))
+	 (should (= 2 (length p-e-fprs)))
+	 (should (= 2 (length p-s-fprs)))
+	 (should (member "1E6BFA973D9E3103B77FD399C3999CF1268DBEA2" p-e-fprs))
+	 (should (member "14632ECAB9E227369C8DD97BF7E79AB7AE31D471" p-e-fprs))
+	 (should (member "1E6BFA973D9E3103B77FD399C3999CF1268DBEA2" p-s-fprs))
+	 (should (member "14632ECAB9E227369C8DD97BF7E79AB7AE31D471" p-s-fprs)))
+       ;; Duplicate record does not change anything.
+       (mml-secure-cust-record-keys
+	pcontext 'encrypt "sub@example.org"
+	(epg-list-keys pcontext "1E6BFA973D9E3103B77FD399C3999CF1268DBEA2"))
+       (mml-secure-cust-record-keys
+	pcontext 'sign "sub@example.org"
+	(epg-list-keys pcontext "1E6BFA973D9E3103B77FD399C3999CF1268DBEA2"))
+       (let ((p-e-fprs (mml-secure-cust-fpr-lookup
+			pcontext 'encrypt "sub@example.org"))
+	     (p-s-fprs (mml-secure-cust-fpr-lookup
+			pcontext 'sign "sub@example.org")))
+	 (should (= 2 (length p-e-fprs)))
+	 (should (= 2 (length p-s-fprs))))
+
+       ;; S/MIME preferences via scontext
+       (dolist (key skeys nil)
+	 (mml-secure-cust-record-keys
+	  scontext 'encrypt "sub@example.org"
+	  (epg-list-keys scontext key))
+	 (mml-secure-cust-record-keys
+	  scontext 'sign "sub@example.org"
+	  (epg-list-keys scontext key 'secret)))
+       (let ((s-e-fprs (mml-secure-cust-fpr-lookup
+			scontext 'encrypt "sub@example.org"))
+	     (s-s-fprs (mml-secure-cust-fpr-lookup
+			scontext 'sign "sub@example.org")))
+	 (should (= 2 (length s-e-fprs)))
+	 (should (= 2 (length s-s-fprs))))
+       ))))
+
+(defun mml-secure-test-en-decrypt
+    (method to from
+	    &optional checksig checkplain enc-keys expectfail interactive)
+  "Encrypt message using METHOD, addressed to TO, from FROM.
+If optional CHECKSIG is non-nil, it must be a number, and a signature check is
+performed; the number indicates how many signatures are expected.
+If optional CHECKPLAIN is non-nil, the expected plaintext should be obtained
+via decryption.
+If optional ENC-KEYS is non-nil, it is a list of pairs of encryption keys (for
+OpenPGP and S/SMIME) expected in `epg-debug-buffer'.
+If optional EXPECTFAIL is non-nil, a decryption failure is expected.
+Pass optional INTERACTIVE to mml-secure-test-mail-fixture."
+  (mml-secure-test-mail-fixture method to from
+   (lambda (gnus-info plaintext decrypted)
+     (if expectfail
+	 (should-not (equal plaintext decrypted))
+       (when checkplain
+	 (should (equal plaintext decrypted)))
+       (let ((protocol (if (memq method
+				 '(enc-smime enc-sign-smime sign-smime))
+			   'CMS
+			 'OpenPGP)))
+	 (when checksig
+	   (let* ((context (epg-make-context protocol))
+		  (signer-names (mml-secure-signer-names protocol from))
+		  (signer-keys (mml-secure-signers context signer-names))
+		  (signer-fprs (mapcar 'mml-secure-fingerprint signer-keys)))
+	     (should (eq checksig (length signer-fprs)))
+	     (if (eq checksig 0)
+		 ;; First key in keyring
+		 (should (string-match-p
+			  (concat "Good signature from "
+				  (if (eq protocol 'CMS)
+				      "0E58229B80EE33959FF718FEEF25402B479DC6E2"
+				    "02372A42CA6D40FB"))
+			  gnus-info)))
+	     (dolist (fpr signer-fprs nil)
+	       ;; OpenPGP: "Good signature from 02372A42CA6D40FB No Expiry <no-exp@example.org> (trust undefined) created ..."
+	       ;; S/MIME:  "Good signature from D06AA118653CC38E9D0CAF56ED7A2135E1582177 /CN=No Expiry (trust full) ..."
+	       (should (string-match-p
+			(concat "Good signature from "
+				(if (eq protocol 'CMS)
+				    fpr
+				  (substring fpr -16 nil)))
+			gnus-info)))))
+	 (when enc-keys
+	   (with-current-buffer epg-debug-buffer
+	     (goto-char (point-min))
+	     ;; The following regexp does not necessarily match at the
+	     ;; start of the line as a path may or may not be present.
+	     ;; Also note that gpg.* matches gpg2 and gpgsm as well.
+	     (let* ((line (concat "gpg.*--encrypt.*$"))
+		    (end (re-search-forward line))
+		    (match (match-string 0)))
+	       (should (and end match))
+	       (dolist (pair enc-keys nil)
+		 (let ((fpr (if (eq protocol 'OpenPGP)
+				(car pair)
+			      (cdr pair))))
+		   (should (string-match-p (concat "-r " fpr) match))))
+	       (goto-char (point-max))
+	       ))))))
+   interactive))
+
+(defvar mml-smime-cache-passphrase)
+(defvar mml2015-cache-passphrase)
+(defvar mml1991-cache-passphrase)
+
+(defun mml-secure-test-en-decrypt-with-passphrase
+    (method to from checksig jl-passphrase do-cache
+	    &optional enc-keys expectfail)
+  "Call mml-secure-test-en-decrypt with changed passphrase caching.
+Args METHOD, TO, FROM, CHECKSIG are passed to mml-secure-test-en-decrypt.
+JL-PASSPHRASE is fixed as return value for `read-passwd',
+boolean DO-CACHE determines whether to cache the passphrase.
+If optional ENC-KEYS is non-nil, it is a list of encryption keys expected
+in `epg-debug-buffer'.
+If optional EXPECTFAIL is non-nil, a decryption failure is expected."
+  (let ((mml-secure-cache-passphrase do-cache)
+	(mml1991-cache-passphrase do-cache)
+	(mml2015-cache-passphrase do-cache)
+	(mml-smime-cache-passphrase do-cache)
+	)
+    (cl-letf (((symbol-function 'read-passwd)
+               (lambda (_prompt &optional _confirm _default) jl-passphrase)))
+      (mml-secure-test-en-decrypt method to from checksig t enc-keys expectfail)
+      )))
+
+(ert-deftest mml-secure-en-decrypt-1 ()
+  "Encrypt message; then decrypt and test for expected result.
+In this test, the single matching key is chosen automatically."
+  (skip-unless (test-conf))
+  (dolist (method (enc-standards) nil)
+    ;; no-exp@example.org with single encryption key
+    (mml-secure-test-en-decrypt
+     method "no-exp@example.org" "sub@example.org" nil t
+     (list (cons "02372A42CA6D40FB" "ED7A2135E1582177")))))
+
+(ert-deftest mml-secure-en-decrypt-2 ()
+  "Encrypt message; then decrypt and test for expected result.
+In this test, the encryption key needs to fixed among multiple ones."
+  (skip-unless (test-conf))
+  (skip-unless (ignore-errors (epg-find-configuration 'CMS)))
+  ;; sub@example.org with multiple candidate keys,
+  ;; fixture customizes preferred ones.
+  (mml-secure-test-key-fixture
+   (lambda ()
+     (dolist (method (enc-standards) nil)
+       (mml-secure-test-en-decrypt
+	method "sub@example.org" "no-exp@example.org" nil t
+	(list (cons "C3999CF1268DBEA2" "EF25402B479DC6E2")))))))
+
+(ert-deftest mml-secure-en-decrypt-3 ()
+  "Encrypt message; then decrypt and test for expected result.
+In this test, encrypt-to-self variables are set to t."
+  ;; Random failures with "wrong-type-argument stringp nil".
+  ;; Seems unlikely to be specific to hydra.nixos.org...
+  :tags (if (getenv "EMACS_HYDRA_CI") '(:unstable))
+  (skip-unless (test-conf))
+  (skip-unless (ignore-errors (epg-find-configuration 'CMS)))
+  ;; sub@example.org with multiple candidate keys,
+  ;; fixture customizes preferred ones.
+  (mml-secure-test-key-fixture
+   (lambda ()
+     (let ((mml-secure-openpgp-encrypt-to-self t)
+	   (mml-secure-smime-encrypt-to-self t))
+       (dolist (method (enc-standards) nil)
+	 (mml-secure-test-en-decrypt
+	  method "sub@example.org" "no-exp@example.org" nil t
+	  (list (cons "C3999CF1268DBEA2" "EF25402B479DC6E2")
+		(cons "02372A42CA6D40FB" "ED7A2135E1582177"))))))))
+
+(ert-deftest mml-secure-en-decrypt-4 ()
+  "Encrypt message; then decrypt and test for expected result.
+In this test, encrypt-to-self variables are set to lists."
+  (skip-unless (test-conf))
+  ;; Send from sub@example.org, which has two keys; encrypt to both.
+  (let ((mml-secure-openpgp-encrypt-to-self
+	 '("C3999CF1268DBEA2" "F7E79AB7AE31D471"))
+	(mml-secure-smime-encrypt-to-self
+	 '("EF25402B479DC6E2" "4035D59B5F88E9FC")))
+    (dolist (method (enc-standards) nil)
+      (mml-secure-test-en-decrypt
+       method "no-exp@example.org" "sub@example.org" nil t
+       (list (cons "C3999CF1268DBEA2" "EF25402B479DC6E2")
+	     (cons "F7E79AB7AE31D471" "4035D59B5F88E9FC"))))))
+
+(ert-deftest mml-secure-en-decrypt-sign-1-1-single ()
+  "Sign and encrypt message; then decrypt and test for expected result.
+In this test, just multiple encryption and signing keys may be available."
+  :tags '(:unstable)
+  (skip-unless (test-conf))
+  (mml-secure-test-key-fixture
+   (lambda ()
+     (let ((mml-secure-openpgp-sign-with-sender t)
+	   (mml-secure-smime-sign-with-sender t))
+       (dolist (method (enc-sign-standards) nil)
+	 ;; no-exp with just one key
+	 (mml-secure-test-en-decrypt
+	  method "no-exp@example.org" "no-exp@example.org" 1 t)
+	 ;; customized choice for encryption key
+	 (mml-secure-test-en-decrypt
+	  method "sub@example.org" "no-exp@example.org" 1 t)
+	 ;; customized choice for signing key
+	 (mml-secure-test-en-decrypt
+	  method "no-exp@example.org" "sub@example.org" 1 t)
+	 ;; customized choice for both keys
+	 (mml-secure-test-en-decrypt
+	  method "sub@example.org" "sub@example.org" 1 t)
+	 )))))
+
+(ert-deftest mml-secure-en-decrypt-sign-1-2-double ()
+  "Sign and encrypt message; then decrypt and test for expected result.
+In this test, just multiple encryption and signing keys may be available."
+  :tags '(:unstable)
+  (skip-unless (test-conf))
+  (mml-secure-test-key-fixture
+   (lambda ()
+     (let ((mml-secure-openpgp-sign-with-sender t)
+	   (mml-secure-smime-sign-with-sender t))
+       ;; Now use both keys to sign.  The customized one via sign-with-sender,
+       ;; the other one via the following setting.
+       (let ((mml-secure-openpgp-signers '("F7E79AB7AE31D471"))
+	     (mml-secure-smime-signers '("0x5F88E9FC")))
+	 (dolist (method (enc-sign-standards) nil)
+	   (mml-secure-test-en-decrypt
+	    method "no-exp@example.org" "sub@example.org" 2 t)))))))
+
+(ert-deftest mml-secure-en-decrypt-sign-1-3-double ()
+  "Sign and encrypt message; then decrypt and test for expected result.
+In this test, just multiple encryption and signing keys may be available."
+  :tags '(:unstable)
+  (skip-unless (test-conf))
+  (mml-secure-test-key-fixture
+   (lambda ()
+     ;; Now use both keys for sub@example.org to sign an e-mail from
+     ;; a different address (without associated keys).
+     (let ((mml-secure-openpgp-sign-with-sender nil)
+	   (mml-secure-smime-sign-with-sender nil)
+	   (mml-secure-openpgp-signers
+	    '("F7E79AB7AE31D471" "C3999CF1268DBEA2"))
+	   (mml-secure-smime-signers '("0x5F88E9FC" "0x479DC6E2")))
+       (dolist (method (enc-sign-standards) nil)
+	 (mml-secure-test-en-decrypt
+	  method "no-exp@example.org" "no-keys@example.org" 2 t))))))
+
+(ert-deftest mml-secure-en-decrypt-sign-2 ()
+  "Sign and encrypt message; then decrypt and test for expected result.
+In this test, lists of encryption and signing keys are customized."
+  :tags '(:unstable)
+  (skip-unless (test-conf))
+  (mml-secure-test-key-fixture
+   (lambda ()
+     (let ((mml-secure-key-preferences
+	    '((OpenPGP (sign) (encrypt)) (CMS (sign) (encrypt))))
+	   (pcontext (epg-make-context 'OpenPGP))
+	   (scontext (epg-make-context 'CMS))
+	   (mml-secure-openpgp-sign-with-sender t)
+	   (mml-secure-smime-sign-with-sender t))
+       (dolist (key '("F7E79AB7AE31D471" "C3999CF1268DBEA2") nil)
+	 (mml-secure-cust-record-keys
+	  pcontext 'encrypt "sub@example.org" (epg-list-keys pcontext key))
+	 (mml-secure-cust-record-keys
+	  pcontext 'sign "sub@example.org" (epg-list-keys pcontext key t)))
+       (dolist (key '("0x5F88E9FC" "0x479DC6E2") nil)
+	 (mml-secure-cust-record-keys
+	  scontext 'encrypt "sub@example.org" (epg-list-keys scontext key))
+	 (mml-secure-cust-record-keys
+	  scontext 'sign "sub@example.org" (epg-list-keys scontext key t)))
+       (dolist (method (enc-sign-standards) nil)
+	 ;; customized choice for encryption key
+	 (mml-secure-test-en-decrypt
+	  method "sub@example.org" "no-exp@example.org" 1 t)
+	 ;; customized choice for signing key
+	 (mml-secure-test-en-decrypt
+	  method "no-exp@example.org" "sub@example.org" 2 t)
+	 ;; customized choice for both keys
+	 (mml-secure-test-en-decrypt
+	  method "sub@example.org" "sub@example.org" 2 t)
+	 )))))
+
+(ert-deftest mml-secure-en-decrypt-sign-3 ()
+  "Sign and encrypt message; then decrypt and test for expected result.
+Use sign-with-sender and encrypt-to-self."
+  :tags '(:unstable)
+  (skip-unless (test-conf))
+  (mml-secure-test-key-fixture
+   (lambda ()
+     (let ((mml-secure-openpgp-sign-with-sender t)
+	   (mml-secure-openpgp-encrypt-to-self t)
+	   (mml-secure-smime-sign-with-sender t)
+	   (mml-secure-smime-encrypt-to-self t))
+       (dolist (method (enc-sign-standards) nil)
+	 (mml-secure-test-en-decrypt
+	  method "sub@example.org" "no-exp@example.org" 1 t
+	  (list (cons "C3999CF1268DBEA2" "EF25402B479DC6E2")
+		(cons "02372A42CA6D40FB" "ED7A2135E1582177"))))
+       ))))
+
+(ert-deftest mml-secure-sign-verify-1 ()
+  "Sign message with sender; then verify and test for expected result."
+  (skip-unless (test-conf))
+  (skip-unless (ignore-errors (epg-find-configuration 'CMS)))
+  (mml-secure-test-key-fixture
+   (lambda ()
+     (dolist (method (sign-standards) nil)
+       (let ((mml-secure-openpgp-sign-with-sender t)
+	     (mml-secure-smime-sign-with-sender t))
+	 ;; A single signing key for sender sub@example.org is customized
+	 ;; in the fixture.
+	 (mml-secure-test-en-decrypt
+	  method "uid1@example.org" "sub@example.org" 1 nil)
+
+	 ;; From sub@example.org, sign with two keys;
+	 ;; sign-with-sender and one from signers-variable:
+	 (let ((mml-secure-openpgp-signers '("02372A42CA6D40FB"))
+	       (mml-secure-smime-signers
+		'("D06AA118653CC38E9D0CAF56ED7A2135E1582177")))
+	   (mml-secure-test-en-decrypt
+	    method "no-exp@example.org" "sub@example.org" 2 nil))
+	 )))))
+
+(ert-deftest mml-secure-sign-verify-3 ()
+  "Try to sign message with expired OpenPGP subkey, which raises an error.
+With Ma Gnus v0.14 and earlier a signature would be created with a wrong key."
+  (skip-unless (test-conf))
+  (should-error
+   (mml-secure-test-key-fixture
+    (lambda ()
+      (let ((with-smime nil)
+	    (mml-secure-openpgp-sign-with-sender nil)
+	    (mml-secure-openpgp-signers '("501FFD98")))
+	(dolist (method (sign-standards) nil)
+	  (mml-secure-test-en-decrypt
+	   method "no-exp@example.org" "sign@example.org" 1 nil)
+	  ))))))
+
+;; TODO Passphrase passing and caching in Emacs does not seem to work
+;; with gpgsm at all.
+;; Independently of caching settings, a pinentry dialogue is displayed.
+;; Thus, the following tests require the user to enter the correct gpgsm
+;; passphrases at the correct points in time.  (Either empty string or
+;; "Passphrase".)
+(ert-deftest mml-secure-en-decrypt-passphrase-cache ()
+  "Encrypt message; then decrypt and test for expected result.
+In this test, a key is used that requires the passphrase \"Passphrase\".
+In the first decryption this passphrase is hardcoded, in the second one it
+ is taken from a cache."
+  (skip-unless (test-conf))
+  (ert-skip "Requires passphrase")
+  (mml-secure-test-key-fixture
+   (lambda ()
+     (dolist (method (enc-standards) nil)
+       (mml-secure-test-en-decrypt-with-passphrase
+	method "uid1@example.org" "sub@example.org" nil
+	;; Beware!  For passphrases copy-sequence is necessary, as they may
+	;; be erased, which actually changes the function's code and causes
+	;; multiple invocations to fail.  I was surprised...
+	(copy-sequence "Passphrase") t)
+       (mml-secure-test-en-decrypt-with-passphrase
+	method "uid1@example.org" "sub@example.org" nil
+	(copy-sequence "Incorrect") t)))))
+
+(defun mml-secure-en-decrypt-passphrase-no-cache (method)
+  "Encrypt message with METHOD; then decrypt and test for expected result.
+In this test, a key is used that requires the passphrase \"Passphrase\".
+In the first decryption this passphrase is hardcoded, but caching disabled.
+So the second decryption fails."
+  (mml-secure-test-key-fixture
+   (lambda ()
+     (mml-secure-test-en-decrypt-with-passphrase
+      method "uid1@example.org" "sub@example.org" nil
+      (copy-sequence "Passphrase") nil)
+     (mml-secure-test-en-decrypt-with-passphrase
+      method "uid1@example.org" "sub@example.org" nil
+      (copy-sequence "Incorrect") nil nil t))))
+
+(ert-deftest mml-secure-en-decrypt-passphrase-no-cache-openpgp-todo ()
+  "Passphrase caching with OpenPGP only for GnuPG 1.x."
+  (skip-unless (test-conf))
+  (skip-unless (string< (cdr (assq 'version (epg-find-configuration 'OpenPGP)))
+			"2"))
+  (mml-secure-en-decrypt-passphrase-no-cache 'enc-pgp)
+  (mml-secure-en-decrypt-passphrase-no-cache 'enc-pgp-mime))
+
+(ert-deftest mml-secure-en-decrypt-passphrase-no-cache-smime-todo ()
+  "Passphrase caching does not work with S/MIME (and gpgsm)."
+  :expected-result :failed
+  (skip-unless (test-conf))
+  (if with-smime
+      (mml-secure-en-decrypt-passphrase-no-cache 'enc-smime)
+    (should nil)))
+
+
+;; Test truncation of question in y-or-n-p.
+(defun mml-secure-select-preferred-keys-todo ()
+  "Manual customization with truncated question."
+  (mml-secure-test-key-fixture
+   (lambda ()
+     (mml-secure-test-en-decrypt
+      'enc-pgp-mime
+      "jens.lechtenboerger@informationelle-selbstbestimmung-im-internet.de"
+      "no-exp@example.org" nil t nil nil t))))
+
+(defun mml-secure-select-preferred-keys-ok ()
+  "Manual customization with entire question."
+  (mml-secure-test-fixture
+   (lambda ()
+     (mml-secure-select-preferred-keys
+      (epg-make-context 'OpenPGP)
+      '("jens.lechtenboerger@informationelle-selbstbestimmung-im-internet.de")
+      'encrypt))
+   t))
+
+
+;; ERT entry points
+(defun mml-secure-run-tests ()
+    "Run all tests with defaults."
+  (ert-run-tests-batch))
+
+(defun mml-secure-run-tests-with-gpg2 ()
+  "Run all tests with gpg2 instead of gpg."
+  (let* ((epg-gpg-program "gpg2"); ~/local/gnupg-2.1.9/PLAY/inst/bin/gpg2
+	 (gpg-version (cdr (assq 'version (epg-find-configuration 'OpenPGP))))
+	 ;; Empty passphrases do not seem to work with gpgsm in 2.1.x:
+	 ;; https://lists.gnupg.org/pipermail/gnupg-users/2015-October/054575.html
+	 (with-smime (string< gpg-version "2.1")))
+    (ert-run-tests-batch)))
+
+(defun mml-secure-run-tests-without-smime ()
+    "Skip S/MIME tests (as they require manual passphrase entry)."
+  (let ((with-smime nil))
+    (ert-run-tests-batch)))
+
+(defun mml-sec-test--kill-gpg-agent ()
+  (dolist (pid (list-system-processes))
+    (let ((atts (process-attributes pid)))
+      (when (and (equal (cdr (assq 'user atts)) (user-login-name))
+                 (or (equal (cdr (assq 'comm atts)) "gpg-agent")
+		     (equal (cdr (assq 'comm atts)) "scdaemon"))
+                 (string-match
+                  (concat "homedir.*"
+                          (regexp-quote (directory-file-name
+                                         (ert-resource-directory))))
+                  (cdr (assq 'args atts))))
+        (call-process "kill" nil nil nil (format "%d" pid))))))
+
+;;; mml-sec-tests.el ends here
diff --git a/test/lisp/gnus/nnrss-tests.el b/test/lisp/gnus/nnrss-tests.el
new file mode 100644
index 00000000000..47d208cb160
--- /dev/null
+++ b/test/lisp/gnus/nnrss-tests.el
@@ -0,0 +1,45 @@
+;;; nnrss-tests.el --- tests for gnus/nnrss.el    -*- lexical-binding:t -*-
+
+;; Copyright (C) 2019-2022 Free Software Foundation, Inc.
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs 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 3 of the License, or
+;; (at your option) any later version.
+
+;; GNU Emacs 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 GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
+
+;;; Code:
+
+(require 'ert)
+(require 'nnrss)
+
+(ert-deftest test-nnrss-normalize ()
+  (should (equal (nnrss-normalize-date "2004-09-17T05:09:49.001+00:00")
+                 "Fri, 17 Sep 2004 05:09:49 +0000")))
+
+(defconst test-nnrss-xml
+  '((rss
+     ((version . "2.0")
+      (xmlns:dc . "http://purl.org/dc/elements/1.1/"))
+     (channel
+      ((xmlns:content . "http://purl.org/rss/1.0/modules/content/"))))))
+
+(ert-deftest test-nnrss-namespace-top ()
+  (should (equal (nnrss-get-namespace-prefix
+                  test-nnrss-xml "http://purl.org/dc/elements/1.1/")
+                 "dc:")))
+(ert-deftest test-nnrss-namespace-inner ()
+  (should (equal (nnrss-get-namespace-prefix
+                  test-nnrss-xml "http://purl.org/rss/1.0/modules/content/")
+                 "content:")))
+
+;;; nnrss-tests.el ends here