bug#70127: 29.3; ERC 5.6-git: /ignore timeouts are not cancelled/reset

["J.P." <jp@neverwas.me>]

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Alcor via General discussion about ERC <emacs-erc@gnu.org> writes:

> Severity: wishlist
>
> On Erc (5.6snapshot0.20240323.151032):
>
> 1. /IGNORE a specific nick with an explicit timeout (e.g. 5m)
> 2. /IGNORE the same nick again with a different timeout (e.g. 10m)
>
> Expected behavior:
>
> The /IGNORE'ed nick is unignored after 10 minutes.
>
> Observed behavior:
>
> The /IGNORE'ed nick is unignored after 5 minutes, afterwhich it is
> unignored again after 10 minutes. The latter command is a no-op though,
> as the nick would be already unignored at that point.

I'm taking the liberty of "extending" this bug to include a somewhat
related issue. I suppose that's bad practice, but it'll allow us to roll
the original request into the fix without much hassle.

From Emacs -Q:

1. M-x erc RET localhost RET RET RET RET
2. /ignore foo RET
3. Hit RET to forgo adding a timer (doesn't impact result)
4. /unignore fool RET ; note the trailing "l"
5. Answer "y" when asked whether to remove "foo"
6. /ignore RET
7. Notice "foo" is still listed and still appears in `erc-ignore-list'

The attached patch tries to address this issue as well as the original
UX problem regarding rustic timeout handling, with ideas borrowed from
Alcor's gist shared on the emacs-erc list.

Not to keep harping on this, but I'd much rather we rewrite the ignore
and lurker stuff completely and move it to a new module in a new file.
Anyone feeling up to the challenge, please step forward. Thanks.


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From 61d5b7ae9eb7adb1b04383dae1498c957f0608b5 Mon Sep 17 00:00:00 2001
From: "F. Jason Park" <jp@neverwas.me>
Date: Mon, 1 Apr 2024 15:27:47 -0700
Subject: [PATCH] [5.6] Allow updating of /IGNORE timeouts in ERC

* lisp/erc/erc.el (erc--read-time-period, erc--decode-time-period):
Move body of former, now a superficial wrapper, to latter, a new
function.
(erc--labeled-time-duration): New function.
(erc--get-ignore-timer-args): New function.
(erc--find-ignore-timer): New function to search through `timer-list'
to find registered timer.
(erc-cmd-IGNORE): Refactor.  Add new optional `timespec' parameter.
Update an existing timer instead of always creating one, and display
time remaining in "ignore list" output.  Pass server buffer instead of
current buffer to timer callbacks because `erc--unignore-user'
displays its messages in the `active' buffer, not necessarily the
issuing one.  However, doing this does discard potentially useful
information.  If ever reverting, we can change the `cl-find' :test in
`erc--find-ignore-timer' to something that compares the
`erc-server-process' of both buffers.
;;
;; Something like:
;;
;; (defun erc--ignore-timers-equal-p (a b)
;;   (and (equal (car a) (car b))
;;        (eq (buffer-local-value 'erc-server-process (cadr a))
;;            (buffer-local-value 'erc-server-process (cadr b)))))
;;
(erc-cmd-UNIGNORE): Pass `erc-ignore-list' member matching `user'
parameter to `erc--unignore-user' instead of original, raw parameter,
along with the server buffer.
(erc--unignore-user): Cancel existing timer and don't bother switching
to server buffer since we're already there.
(erc-message-english-ignore-list): New variable.
* test/lisp/erc/erc-scenarios-ignore.el: New file.
* test/lisp/erc/erc-tests.el (erc--read-time-period): New test.
(erc-cmd-UNIGNORE): New test.  (Bug#70127)
---
 lisp/erc/erc.el                       | 92 ++++++++++++++++++++-------
 test/lisp/erc/erc-scenarios-ignore.el | 79 +++++++++++++++++++++++
 test/lisp/erc/erc-tests.el            | 24 +++++++
 3 files changed, 172 insertions(+), 23 deletions(-)
 create mode 100644 test/lisp/erc/erc-scenarios-ignore.el

diff --git a/lisp/erc/erc.el b/lisp/erc/erc.el
index 0750463a4e7..909712c8db7 100644
--- a/lisp/erc/erc.el
+++ b/lisp/erc/erc.el
@@ -4191,8 +4191,11 @@ erc--read-time-period
 
 If input is blank, this function returns nil.  Otherwise it
 returns the time spec converted to a number of seconds."
-  (let ((period (string-trim
-                 (read-string prompt nil 'erc--read-time-period-history))))
+  (erc--decode-time-period
+   (string-trim (read-string prompt nil 'erc--read-time-period-history))))
+
+(defun erc--decode-time-period (period)
+  (progn
     (cond
      ;; Blank input.
      ((zerop (length period))
@@ -4223,36 +4226,76 @@ erc--read-time-period
           (user-error "%s is not a valid time period" period))
         (decoded-time-period time))))))
 
-(defun erc-cmd-IGNORE (&optional user)
-  "Ignore USER.  This should be a regexp matching nick!user@host.
-If no USER argument is specified, list the contents of `erc-ignore-list'."
+(defun erc--labeled-time-duration (secs)
+  "Return a string with hour/minute/second labels for duration SECS."
+  (let* ((hours (floor secs 3600))
+         (minutes (floor (mod secs 3600) 60))
+         (seconds (mod secs 60)))
+    (cond ((>= secs 3600) (format "%dh%dm%ds" hours minutes (round seconds)))
+          ((>= secs 60) (format "%dm%ds" minutes (round seconds)))
+          (t (format "%ds" (round seconds))))))
+
+(defun erc--get-ignore-timer-args (inst)
+  ;; The `cl-struct' `pcase' pattern and `cl-struct-slot-value' emit
+  ;; warnings when compiling because `timer' is un-`:named'.
+  (when (and (timerp inst)
+             (eq (aref inst (cl-struct-slot-offset 'timer 'function))
+                 'erc--unignore-user))
+    (aref inst (cl-struct-slot-offset 'timer 'args))))
+
+(defun erc--find-ignore-timer (&rest args)
+  "Find an existing ignore timer."
+  (cl-find args timer-list :key #'erc--get-ignore-timer-args :test #'equal))
+
+(defun erc-cmd-IGNORE (&optional user timespec)
+  "Drop messages from senders, like nick!user@host, matching regexp USER.
+With human-readable TIMESPEC, ignore messages from matched senders for
+the specified duration, like \"20m\".  Without USER, list the contents
+of `erc-ignore-list'."
   (if user
-      (let ((quoted (regexp-quote user)))
+      (let ((quoted (regexp-quote user))
+            (prompt "Add a timeout? (Blank for no, or a time spec like 2h): ")
+            timeout msg)
         (when (and (not (string= user quoted))
                    (y-or-n-p (format "Use regexp-quoted form (%s) instead? "
                                      quoted)))
           (setq user quoted))
-        (let ((timeout
-               (erc--read-time-period
-                "Add a timeout? (Blank for no, or a time spec like 2h): "))
-              (buffer (current-buffer)))
+        (unless timespec
+          (setq timespec
+                (read-string prompt nil 'erc--read-time-period-history)))
+        (setq timeout (erc--decode-time-period (string-trim timespec))
+              msg (if timeout
+                      (format "Now ignoring %s for %s" user
+                              (erc--labeled-time-duration timeout))
+                    (format "Now ignoring %s" user)))
+        (erc-with-server-buffer
           (when timeout
-            (run-at-time timeout nil
-                         (lambda ()
-                           (erc--unignore-user user buffer))))
-          (erc-display-message nil 'notice 'active
-                               (format "Now ignoring %s" user))
-          (erc-with-server-buffer (add-to-list 'erc-ignore-list user))))
+            (if-let ((existing (erc--find-ignore-timer user (current-buffer))))
+                (timer-set-time existing (timer-relative-time nil timeout))
+              (run-at-time timeout nil #'erc--unignore-user user
+                           (current-buffer))))
+          (erc-display-message nil 'notice 'active msg)
+          (cl-pushnew user erc-ignore-list :test #'equal)))
     (if (null (erc-with-server-buffer erc-ignore-list))
         (erc-display-message nil 'notice 'active "Ignore list is empty")
       (erc-display-message nil 'notice 'active "Ignore list:")
-      (mapc (lambda (item)
-              (erc-display-message nil 'notice 'active item))
-            (erc-with-server-buffer erc-ignore-list))))
+      (erc-with-server-buffer
+        (let ((seen (copy-sequence erc-ignore-list)))
+          (dolist (timer timer-list)
+            (when-let ((args (erc--get-ignore-timer-args timer))
+                       ((eq (current-buffer) (nth 1 args)))
+                       (user (car args))
+                       (delta (- (timer-until timer (current-time))))
+                       (duration (erc--labeled-time-duration delta)))
+              (setq seen (delete user seen))
+              (erc-display-message nil 'notice 'active 'ignore-list
+                                   ?p user ?s duration)))
+          (dolist (pattern seen)
+            (erc-display-message nil 'notice 'active pattern))))))
   t)
 
 (defun erc-cmd-UNIGNORE (user)
-  "Remove the user specified in USER from the ignore list."
+  "Remove the first pattern in `erc-ignore-list' matching USER."
   (let ((ignored-nick (car (erc-with-server-buffer
                              (erc-member-ignore-case (regexp-quote user)
                                                      erc-ignore-list)))))
@@ -4264,16 +4307,18 @@ erc-cmd-UNIGNORE
         (erc-display-message nil 'notice 'active
                              (format "%s is not currently ignored!" user))))
     (when ignored-nick
-      (erc--unignore-user user (current-buffer))))
+      (erc--unignore-user ignored-nick (erc-server-buffer))))
   t)
 
 (defun erc--unignore-user (user buffer)
   (when (buffer-live-p buffer)
     (with-current-buffer buffer
+      (cl-assert (erc--server-buffer-p))
       (erc-display-message nil 'notice 'active
                            (format "No longer ignoring %s" user))
-      (erc-with-server-buffer
-        (setq erc-ignore-list (delete user erc-ignore-list))))))
+      (setq erc-ignore-list (delete user erc-ignore-list))
+      (when-let ((existing (erc--find-ignore-timer user buffer)))
+        (cancel-timer existing)))))
 
 (defvar erc--pre-clear-functions nil
   "Abnormal hook run when truncating buffers.
@@ -9299,6 +9344,7 @@ english
     . "\n\n*** Connection failed!  Re-establishing connection...\n")
    (disconnected-noreconnect
     . "\n\n*** Connection failed!  Not re-establishing connection.\n")
+   (ignore-list . "%-8p %s")
    (reconnecting . "Reconnecting in %ms: attempt %i/%n ...")
    (reconnect-canceled . "Canceled %u reconnect timer with %cs to go...")
    (finished . "\n\n*** ERC finished ***\n")
diff --git a/test/lisp/erc/erc-scenarios-ignore.el b/test/lisp/erc/erc-scenarios-ignore.el
new file mode 100644
index 00000000000..c830e9d2c87
--- /dev/null
+++ b/test/lisp/erc/erc-scenarios-ignore.el
@@ -0,0 +1,79 @@
+;;; erc-scenarios-ignore.el --- Misc commands for ERC -*- lexical-binding: t -*-
+
+;; Copyright (C) 2023-2024 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:
+
+;; TODO add test covering the same ignored speaker in two different
+;; channels on the same server: they should be ignored in both.
+
+;;; Code:
+
+(require 'ert-x)
+(eval-and-compile
+  (let ((load-path (cons (ert-resource-directory) load-path)))
+    (require 'erc-scenarios-common)))
+
+(ert-deftest erc-scenarios-ignore/basic ()
+  :tags '(:expensive-test)
+  (erc-scenarios-common-with-cleanup
+      ((erc-scenarios-common-dialog "base/assoc/multi-net")
+       (erc-server-flood-penalty 0.1)
+       (dumb-server-foonet (erc-d-run "localhost" t 'foonet))
+       (dumb-server-barnet (erc-d-run "localhost" t 'barnet))
+       (erc-autojoin-channels-alist '((foonet "#chan") (barnet "#chan")))
+       (port-foonet (process-contact dumb-server-foonet :service))
+       (port-barnet (process-contact dumb-server-barnet :service))
+       (expect (erc-d-t-make-expecter)))
+
+    (ert-info ("Connect to two networks")
+      (with-current-buffer (erc :server "127.0.0.1"
+                                :port port-barnet
+                                :nick "tester"
+                                :password "changeme"
+                                :full-name "tester"))
+      (with-current-buffer (erc :server "127.0.0.1"
+                                :port port-foonet
+                                :nick "tester"
+                                :password "changeme"
+                                :full-name "tester")
+        (funcall expect 10 "debug mode")))
+
+    (with-current-buffer (erc-d-t-wait-for 10 (get-buffer "#chan@foonet"))
+      (funcall expect 10 "<bob> tester, welcome!")
+      (funcall expect 10 "<alice> tester, welcome!")
+      (erc-scenarios-common-say "/ignore alice 1m")
+      (erc-scenarios-common-say "/ignore mike 1h")
+      (funcall expect 10 "ignoring alice for 1m0s")
+      (funcall expect 10 "<bob> alice: Signior Iachimo")
+      (erc-scenarios-common-say "/ignore")
+      (funcall expect 10 "alice    60s")
+      (funcall expect 10 "mike     59m60s")
+      (funcall expect -0.1 "<alice>")
+      (funcall expect 10 "<bob> alice: The ground is bloody")
+      (erc-scenarios-common-say "/unignore alice")
+      (funcall expect 10 "<alice>"))
+
+    ;; No <mike> messages were ignored on network barnet.
+    (with-current-buffer (erc-d-t-wait-for 10 (get-buffer "#chan@barnet"))
+      (funcall expect 10 "<mike> tester, welcome!")
+      (funcall expect 10 "<joe> tester, welcome!")
+      (funcall expect 10 "<mike> joe: Whipp'd")
+      (funcall expect 10 "<mike> joe: Double"))))
+
+;;; erc-scenarios-ignore.el ends here
diff --git a/test/lisp/erc/erc-tests.el b/test/lisp/erc/erc-tests.el
index 3e8ddef3731..ad6074ab6d3 100644
--- a/test/lisp/erc/erc-tests.el
+++ b/test/lisp/erc/erc-tests.el
@@ -50,6 +50,30 @@ erc--read-time-period
   (cl-letf (((symbol-function 'read-string) (lambda (&rest _) "1d")))
     (should (equal (erc--read-time-period "foo: ") 86400))))
 
+(ert-deftest erc--labeled-time-duration ()
+  (should (equal (erc--labeled-time-duration 10) "10s"))
+  (should (equal (erc--labeled-time-duration 10.1) "10s"))
+  (should (equal (erc--labeled-time-duration 100) "1m40s"))
+  (should (equal (erc--labeled-time-duration 100.1) "1m40s"))
+  (should (equal (erc--labeled-time-duration 1000) "16m40s")))
+
+;; This asserts that the first pattern on file matching a supplied
+;; `user' parameter will be removed after confirmation.
+(ert-deftest erc-cmd-UNIGNORE ()
+  (should (local-variable-if-set-p 'erc-ignore-list))
+  (erc-tests-common-make-server-buf)
+
+  (setq erc-ignore-list (list ".")) ; match anything
+  (ert-simulate-keys (list ?\r)
+    (erc-cmd-IGNORE "abc"))
+  (should (equal erc-ignore-list '("abc" ".")))
+
+  (cl-letf (((symbol-function 'y-or-n-p) #'always))
+    (erc-cmd-UNIGNORE "abcdef")
+    (should (equal erc-ignore-list '(".")))
+    (erc-cmd-UNIGNORE "foo"))
+  (should-not erc-ignore-list))
+
 (ert-deftest erc-with-all-buffers-of-server ()
   (let (proc-exnet
         proc-onet
-- 
2.44.0