>From 636bec56194f964907c5cf5d37f2cb18e338e64e Mon Sep 17 00:00:00 2001
From: "F. Jason Park" <jp@neverwas.me>
Date: Thu, 19 Jan 2023 21:07:27 -0800
Subject: [PATCH 7/7] [5.6] Convert ERC's Imenu integration into proper module

TODO: add news item once a section for 5.6 has been added.

* lisp/erc/erc-goodies.el: Don't add Imenu hooks to `erc-mode-hook' at
top level. Remove autoload for `erc-create-imenu-index' because it
already exists in the `erc-imenu' library.
(erc-imenu-setup) Move to erc-imenu.
* lisp/erc/erc-imenu.el (erc-unfill-notice): Allow modifications to
read-only text.  Thanks to Yusef Aslam for reporting this bug.
(erc-imenu-setup): Move here from goodies.
(erc-imenu-mode, erc-imenu-enable, erc-imenu-disable): Create new
ERC module for Imenu.
* lisp/erc/erc.el (erc-modules): Add `imenu' to default value and
create menu item.  Update package-version.
* test/lisp/erc/erc-tests.el (erc-tests--modules): Add
`imenu'.  (Bug#60954.)
---
 lisp/erc/erc-goodies.el    |  6 ------
 lisp/erc/erc-imenu.el      | 23 ++++++++++++++++++++++-
 lisp/erc/erc.el            |  4 +++-
 test/lisp/erc/erc-tests.el |  2 +-
 4 files changed, 26 insertions(+), 9 deletions(-)

diff --git a/lisp/erc/erc-goodies.el b/lisp/erc/erc-goodies.el
index 5ddacb643fd..7ea6c42ec65 100644
--- a/lisp/erc/erc-goodies.el
+++ b/lisp/erc/erc-goodies.el
@@ -32,12 +32,6 @@
 (eval-when-compile (require 'cl-lib))
 (require 'erc)
 
-(defun erc-imenu-setup ()
-  "Setup Imenu support in an ERC buffer."
-  (setq-local imenu-create-index-function #'erc-create-imenu-index))
-
-(add-hook 'erc-mode-hook #'erc-imenu-setup)
-(autoload 'erc-create-imenu-index "erc-imenu" "Imenu index creation function")
 
 ;;; Automatically scroll to bottom
 (defcustom erc-input-line-position nil
diff --git a/lisp/erc/erc-imenu.el b/lisp/erc/erc-imenu.el
index 6223cd3d06f..526afd32249 100644
--- a/lisp/erc/erc-imenu.el
+++ b/lisp/erc/erc-imenu.el
@@ -52,7 +52,8 @@ erc-unfill-notice
 			 (forward-line 1)
 			 (looking-at "    "))
 		  (forward-line 1))
-		(end-of-line) (point)))))
+		(end-of-line) (point))))
+	(inhibit-read-only t))
     (with-temp-buffer
       (insert str)
       (goto-char (point-min))
@@ -124,6 +125,26 @@ erc-create-imenu-index
 				  index-alist))
     index-alist))
 
+(defvar-local erc-imenu--create-index-function nil
+  "Previous local value of `imenu-create-index-function', if any.")
+
+(defun erc-imenu-setup ()
+  "Wire up support for Imenu in an ERC buffer."
+  (when (and (local-variable-p 'imenu-create-index-function)
+             imenu-create-index-function)
+    (setq erc-imenu--create-index-function imenu-create-index-function))
+  (setq imenu-create-index-function #'erc-create-imenu-index))
+
+;;;###autoload(autoload 'erc-imenu-mode "erc-imenu" nil t)
+(define-erc-module imenu nil
+  "Simple Imenu integration for ERC."
+  ((add-hook 'erc-mode-hook #'erc-imenu-setup))
+  ((remove-hook 'erc-mode-hook #'erc-imenu-setup)
+   (erc-with-all-buffers-of-server erc-server-process nil
+     (when erc-imenu--create-index-function
+       (setq imenu-create-index-function erc-imenu--create-index-function)
+       (kill-local-variable 'erc-imenu--create-index-function)))))
+
 (provide 'erc-imenu)
 
 ;;; erc-imenu.el ends here
diff --git a/lisp/erc/erc.el b/lisp/erc/erc.el
index 4f985da9651..e122f32d96a 100644
--- a/lisp/erc/erc.el
+++ b/lisp/erc/erc.el
@@ -1834,7 +1834,7 @@ erc-migrate-modules
 
 (defcustom erc-modules '(netsplit fill button match track completion readonly
                                   networks ring autojoin noncommands irccontrols
-                                  move-to-prompt stamp menu list)
+                                  move-to-prompt stamp menu list imenu)
   "A list of modules which ERC should enable.
 If you set the value of this without using `customize' remember to call
 \(erc-update-modules) after you change it.  When using `customize', modules
@@ -1894,6 +1894,7 @@ erc-modules
     (const :tag "dcc: Provide Direct Client-to-Client support" dcc)
     (const :tag "fill: Wrap long lines" fill)
     (const :tag "identd: Launch an identd server on port 8113" identd)
+    (const :tag "imenu: A simple Imenu integration" imenu)
     (const :tag "irccontrols: Highlight or remove IRC control characters"
            irccontrols)
     (const :tag "keep-place: Leave point above un-viewed text" keep-place)
@@ -1931,6 +1932,7 @@ erc-modules
     (const :tag "unmorse: Translate morse code in messages" unmorse)
     (const :tag "xdcc: Act as an XDCC file-server" xdcc)
     (repeat :tag "Others" :inline t symbol))
+  :package-version '(ERC . "5.6") ; FIXME sync on release
   :group 'erc)
 
 (defun erc-update-modules ()
diff --git a/test/lisp/erc/erc-tests.el b/test/lisp/erc/erc-tests.el
index 2c5c2541bca..3e844f45f1a 100644
--- a/test/lisp/erc/erc-tests.el
+++ b/test/lisp/erc/erc-tests.el
@@ -1270,7 +1270,7 @@ erc-handle-irc-url
 
 (defconst erc-tests--modules
   '( autoaway autojoin button capab-identify completion dcc fill identd
-     irccontrols keep-place list log match menu move-to-prompt netsplit
+     imenu irccontrols keep-place list log match menu move-to-prompt netsplit
      networks noncommands notifications notify page readonly
      replace ring sasl scrolltobottom services smiley sound
      spelling stamp track truncate unmorse xdcc))
-- 
2.39.2