From fdd8b5913baa3a8f7cbb8b51ad6d092a41c04a90 Mon Sep 17 00:00:00 2001
From: Philip Kaludercic <philipk@posteo.net>
Date: Sat, 12 Mar 2022 22:18:49 +0100
Subject: [PATCH] Add rcirc-cycle-completion-flag

* doc/misc/rcirc.texi: Document new option.
* lisp/net/rcirc.el (rcirc-cycle-completion-flag): Add new option.
(rcirc-mode): Respect new option.
---
 doc/misc/rcirc.texi |  3 +++
 etc/NEWS            |  6 ++++++
 lisp/net/rcirc.el   | 17 ++++++++++++++++-
 3 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/doc/misc/rcirc.texi b/doc/misc/rcirc.texi
index b18ab2a6b29..8253e404084 100644
--- a/doc/misc/rcirc.texi
+++ b/doc/misc/rcirc.texi
@@ -154,8 +154,11 @@ deego: fsbot rules!
 
 @cindex nick completion
 @cindex completion of nicks
+@vindex rcirc-cycle-completion-flag
 @kindex TAB
 Since this is so common, you can use @key{TAB} to do nick completion.
+By default rcirc will use the default completion system, but you can
+enable @code{rcirc-cycle-completion-flag} to cycle nicks in place.
 
 @node Getting started with rcirc
 @section Getting started with rcirc
diff --git a/etc/NEWS b/etc/NEWS
index 350a4f6da14..7d474ac107f 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -506,6 +506,12 @@ are met.  The conditions are given by the argument, which can be
 +++
 *** New command 'rcirc-when'.
 
++++
+*** New user option 'rcirc-cycle-completion-flag'.
+Rcirc will use the default 'completion-at-point' mechanism.  The
+conventional IRC behaviour of completing by cycling through the
+available options can be restored by enabling this option.
+
 * Editing Changes in Emacs 29.1
 
 ---
diff --git a/lisp/net/rcirc.el b/lisp/net/rcirc.el
index 9d1600ed72f..5fe65cc7b3e 100644
--- a/lisp/net/rcirc.el
+++ b/lisp/net/rcirc.el
@@ -433,6 +433,20 @@ will be killed."
   :version "28.1"
   :type 'boolean)
 
+(defcustom rcirc-cycle-completion-flag nil
+  "Non-nil means to use cycling for completion in rcirc buffers.
+See the Info node `(emacs) Completion Options' for background on
+what cycling completion means."
+  :version "29.1"
+  :set (lambda (sym val)
+         (dolist (buf (match-buffers '(major-mode . rcirc-mode)))
+           (with-current-buffer buf
+             (if val
+                 (setq-local completion-cycle-threshold t)
+               (kill-local-variable 'completion-cycle-threshold))))
+         (set-default sym val))
+  :type 'boolean)
+
 (defvar-local rcirc-nick nil
   "The nickname used for the current connection.")
 
@@ -1434,7 +1448,8 @@ PROCESS is the process object used for communication.
 
   (add-hook 'completion-at-point-functions
             'rcirc-completion-at-point nil 'local)
-  (setq-local completion-cycle-threshold t)
+  (when rcirc-cycle-completion-flag
+    (setq-local completion-cycle-threshold t))
 
   (run-mode-hooks 'rcirc-mode-hook))
 
-- 
2.39.5