Re: Add compat to ERC

From 1a5ce365e0b2cd39a1bd3491b44c3fd9d10d5136 Mon Sep 17 00:00:00 2001
From: "F. Jason Park" <[email protected]>
Date: Thu, 14 Jul 2022 23:16:59 -0700
Subject: [PATCH 0/2] *** NOT A PATCH ***

*** BLURB HERE ***

F. Jason Park (2):
  Add temporary compatibility stopgaps to ERC
  Add compat from GNU ELPA as a soft dependency in ERC

 lisp/erc/erc-backend.el  | 36 +++++++-----------------------------
 lisp/erc/erc-compat.el   | 13 +++++++++++++
 lisp/erc/erc-dcc.el      | 12 ++----------
 lisp/erc/erc-speedbar.el | 24 ++++++------------------
 lisp/erc/erc.el          | 33 +++++++++++----------------------
 5 files changed, 39 insertions(+), 79 deletions(-)

Interdiff:
diff --git a/lisp/erc/erc-compat.el b/lisp/erc/erc-compat.el
index 899522f186..dec38df80a 100644
--- a/lisp/erc/erc-compat.el
+++ b/lisp/erc/erc-compat.el
@@ -151,39 +151,17 @@ erc-subseq
 		 (setq i (1+ i) start (1+ start)))
 	       res))))))
 
-;;;; lisp/calendar/time-date.el
-
-(defun erc-compat--28-decoded-time-period (time)
-  "Interpret DECODED as a period and return its length in seconds.
-For computational purposes, years are 365 days long and months
-are 30 days long."
-  (+ (if (consp (decoded-time-second time))
-         ;; Fractional second.
-         (/ (float (car (decoded-time-second time)))
-            (cdr (decoded-time-second time)))
-       (or (decoded-time-second time) 0))
-     (* (or (decoded-time-minute time) 0) 60)
-     (* (or (decoded-time-hour time) 0) 60 60)
-     (* (or (decoded-time-day time) 0) 60 60 24)
-     (* (or (decoded-time-month time) 0) 60 60 24 30)
-     (* (or (decoded-time-year time) 0) 60 60 24 365)))
-
-(defmacro erc-compat--decoded-time-period (time)
-  (declare (indent defun))
-  (list (if (< emacs-major-version 28)
-            'erc-compat--28-decoded-time-period
-          'decoded-time-period)
-        time))
-
 ;;;; lisp/emacs-lisp/subr-x.el
 
-(defmacro erc-compat--with-memoization (table &rest forms)
+(defmacro erc-compat--with-memoization (place &rest forms)
   (declare (indent defun))
-  ;; For now, assume the version in 29 will remain as is.
-  (if (< emacs-major-version 29)
-      `(cl--generic-with-memoization ,table ,@forms)
-    `(with-memoization ,table ,@forms)))
-
+  ;; Degrade as an emergency stopgap in the unlikely event this gets
+  ;; renamed on trunk (does nothing for a change in arity).
+  (cond ((fboundp 'with-memoization) ; t when compiling
+         `(with-memoization ,place ,@forms))
+        ((< 26 emacs-major-version 29)
+         `(cl--generic-with-memoization ,place ,@forms))
+        (t (cons 'progn forms))))
 
 (provide 'erc-compat)
 
diff --git a/lisp/erc/erc.el b/lisp/erc/erc.el
index 613c805b31..3a58a0975e 100644
--- a/lisp/erc/erc.el
+++ b/lisp/erc/erc.el
@@ -3211,7 +3211,7 @@ erc--read-time-period
                     (wrong-type-argument nil))))
         (unless time
           (user-error "%s is not a valid time period" period))
-        (erc-compat--decoded-time-period time))))))
+        (decoded-time-period time))))))
 
 (defun erc-cmd-IGNORE (&optional user)
   "Ignore USER.  This should be a regexp matching nick!user@host.
-- 
2.36.1

From 30d6755c4e943a6d9170aa3281122bff493a2621 Mon Sep 17 00:00:00 2001
From: "F. Jason Park" <[email protected]>
Date: Thu, 14 Jul 2022 22:23:48 -0700
Subject: [PATCH 1/2] Add temporary compatibility stopgaps to ERC

* lisp/erc/erc.el: Load erc-compat.el after main requirements.
Eventually, this will in turn load the compat package from GNU ELPA.
(erc--read-time-period): Use adapter for `decoded-time-period'.
(erc-join-channel): Use adapter for `format-prompt'.

* lisp/erc/erc-backend.el: (erc--with-memoization,
erc-compat--with-memoization): Move to `erc-compat'.

* lisp/erc/erc-compat.el: (erc-compat--28-decoded-time-period,
erc-compat--decoded-time-period): Add adapter and backport definition
for `decoded-time-period'.
(erc-compat--with-memoization): Add adapter for `with-memoization'.
(erc--read-time-period): Use `erc-compat--decoded-time-period'
adapter.
(erc-compat--28-format-prompt, erc-compat--format-prompt): Add
adapters for `format-prompt'.

* lisp/erc/erc-dcc.el: (erc-dcc-do-GET-command): Use adapter for
`format-prompt'.
---
 lisp/erc/erc-backend.el | 12 +--------
 lisp/erc/erc-compat.el  | 59 +++++++++++++++++++++++++++++++++++++++++
 lisp/erc/erc-dcc.el     |  4 +--
 lisp/erc/erc.el         |  6 +++--
 4 files changed, 66 insertions(+), 15 deletions(-)

diff --git a/lisp/erc/erc-backend.el b/lisp/erc/erc-backend.el
index 8be4894ecb..2df2a57690 100644
--- a/lisp/erc/erc-backend.el
+++ b/lisp/erc/erc-backend.el
@@ -1673,16 +1673,6 @@ erc--parse-isupport-value
          (split-string value ",")
        (list value)))))
 
-(defmacro erc--with-memoization (table &rest forms)
-  "Adapter to be migrated to erc-compat."
-  (declare (indent defun))
-  `(cond
-    ((fboundp 'with-memoization)
-     (with-memoization ,table ,@forms)) ; 29.1
-    ((fboundp 'cl--generic-with-memoization)
-     (cl--generic-with-memoization ,table ,@forms))
-    (t ,@forms)))
-
 (defun erc--get-isupport-entry (key &optional single)
   "Return an item for \"ISUPPORT\" token KEY, a symbol.
 When a lookup fails return nil.  Otherwise return a list whose
@@ -1692,7 +1682,7 @@ erc--get-isupport-entry
 primitive value."
   (if-let* ((table (or erc--isupport-params
                        (erc-with-server-buffer erc--isupport-params)))
-            (value (erc--with-memoization (gethash key table)
+            (value (erc-compat--with-memoization (gethash key table)
                      (when-let ((v (assoc (symbol-name key)
                                           erc-server-parameters)))
                        (if (cdr v)
diff --git a/lisp/erc/erc-compat.el b/lisp/erc/erc-compat.el
index 16cfb15a5a..e45b52f0c7 100644
--- a/lisp/erc/erc-compat.el
+++ b/lisp/erc/erc-compat.el
@@ -150,6 +150,65 @@ erc-subseq
 		 (setq i (1+ i) start (1+ start)))
 	       res))))))
 
+;;;; lisp/calendar/time-date.el
+
+(defun erc-compat--28-decoded-time-period (time)
+  "Interpret DECODED as a period and return its length in seconds.
+For computational purposes, years are 365 days long and months
+are 30 days long."
+  (+ (if (consp (decoded-time-second time))
+         ;; Fractional second.
+         (/ (float (car (decoded-time-second time)))
+            (cdr (decoded-time-second time)))
+       (or (decoded-time-second time) 0))
+     (* (or (decoded-time-minute time) 0) 60)
+     (* (or (decoded-time-hour time) 0) 60 60)
+     (* (or (decoded-time-day time) 0) 60 60 24)
+     (* (or (decoded-time-month time) 0) 60 60 24 30)
+     (* (or (decoded-time-year time) 0) 60 60 24 365)))
+
+(defmacro erc-compat--decoded-time-period (time)
+  (declare (indent defun))
+  (list (if (< emacs-major-version 28)
+            'erc-compat--28-decoded-time-period
+          'decoded-time-period)
+        time))
+
+;;;; lisp/minibuffer.el
+
+(defun erc-compat--28-format-prompt (prompt default &rest format-args)
+  (concat
+   (if (null format-args)
+       prompt
+     (apply #'format prompt format-args))
+   (and default
+        (or (not (stringp default))
+            (> (length default) 0))
+        (format " (default %s)"
+                (if (consp default)
+                    (car default)
+                  default)))
+   ": "))
+
+(defmacro erc-compat--format-prompt (&rest rest)
+  (declare (indent defun))
+  (cons (if (< emacs-major-version 28)
+            'erc-compat--28-format-prompt
+          'format-prompt)
+        rest))
+
+;;;; lisp/emacs-lisp/subr-x.el
+
+(defmacro erc-compat--with-memoization (place &rest forms)
+  (declare (indent defun))
+  ;; Degrade as an emergency stopgap in the unlikely event this gets
+  ;; renamed on trunk (does nothing for a change in arity).
+  (cond ((fboundp 'with-memoization) ; t when compiling
+         `(with-memoization ,place ,@forms))
+        ((< 26 emacs-major-version 29)
+         `(cl--generic-with-memoization ,place ,@forms))
+        (t (cons 'progn forms))))
+
 (provide 'erc-compat)
 
 ;;; erc-compat.el ends here
diff --git a/lisp/erc/erc-dcc.el b/lisp/erc/erc-dcc.el
index d0e1848e0e..c8a66dd1d6 100644
--- a/lisp/erc/erc-dcc.el
+++ b/lisp/erc/erc-dcc.el
@@ -520,8 +520,8 @@ erc-dcc-do-GET-command
          (filename (or file (plist-get elt :file) "unknown")))
     (if elt
         (let* ((file (read-file-name
-                      (format-prompt "Local filename"
-                                     (file-name-nondirectory filename))
+                      (erc-compat--format-prompt
+                        "Local filename" (file-name-nondirectory filename))
                       (or erc-dcc-get-default-directory
                           default-directory)
                       (expand-file-name (file-name-nondirectory filename)
diff --git a/lisp/erc/erc.el b/lisp/erc/erc.el
index 0a16831fba..508f0e9620 100644
--- a/lisp/erc/erc.el
+++ b/lisp/erc/erc.el
@@ -69,6 +69,8 @@
 (require 'iso8601)
 (eval-when-compile (require 'subr-x))
 
+(require 'erc-compat)
+
 (defconst erc-version "5.4.1"
   "This version of ERC.")
 
@@ -3209,7 +3211,7 @@ erc--read-time-period
                     (wrong-type-argument nil))))
         (unless time
           (user-error "%s is not a valid time period" period))
-        (decoded-time-period time))))))
+        (erc-compat--decoded-time-period time))))))
 
 (defun erc-cmd-IGNORE (&optional user)
   "Ignore USER.  This should be a regexp matching nick!user@host.
@@ -4480,7 +4482,7 @@ erc-join-channel
           (table (when (erc-server-buffer-live-p)
                    (set-buffer (process-buffer erc-server-process))
                    erc-channel-list)))
-      (completing-read (format-prompt "Join channel" chnl)
+      (completing-read (erc-compat--format-prompt "Join channel" chnl)
                        table nil nil nil nil chnl))
     (when (or current-prefix-arg erc-prompt-for-channel-key)
       (read-string "Channel key (RET for none): "))))
-- 
2.36.1

From 1a5ce365e0b2cd39a1bd3491b44c3fd9d10d5136 Mon Sep 17 00:00:00 2001
From: "F. Jason Park" <[email protected]>
Date: Fri, 8 Jul 2022 04:58:26 -0700
Subject: [PATCH 2/2] Add compat from GNU ELPA as a soft dependency in ERC

FIXME update version in Package-Requires header to appropriate compat
release.

* lisp/erc/erc-backend.el (erc-parse-server-response,
erc--parse-isupport-value): Remove sub-28 compat code involving
`string-search'.

* lisp/erc/erc-compat.el: Require compat package, but don't error
when absent.

* lisp/erc/erc-dcc.el (erc-dcc-member): Remove `string-search' compat
code.
(erc-dcc-unquote-filename): Remove `string-replace' compat code.

* lisp/erc/erc-speedbar.el (erc-speedbar-expand-server,
erc-speedbar-expand-channel, erc-speedbar-expand-user): Remove
`string-search' compat code.

* lisp/erc/erc.el: Add compat version 28.1.1.0 to Package-Requires
header.
(erc--valid-local-channel-p): Remove `string-search' compat code.
(erc-update-mode-line-buffer): Remove `string-replace' compat code.
(erc-message-english-PART): Remove `string-replace' compat code.
---
 lisp/erc/erc-backend.el  | 24 +++++---------------
 lisp/erc/erc-compat.el   | 48 +---------------------------------------
 lisp/erc/erc-dcc.el      | 16 ++++----------
 lisp/erc/erc-speedbar.el | 24 +++++---------------
 lisp/erc/erc.el          | 35 +++++++++--------------------
 5 files changed, 28 insertions(+), 119 deletions(-)

diff --git a/lisp/erc/erc-backend.el b/lisp/erc/erc-backend.el
index 2df2a57690..5858502eb2 100644
--- a/lisp/erc/erc-backend.el
+++ b/lisp/erc/erc-backend.el
@@ -1012,21 +1012,15 @@ erc-parse-server-response
     (save-match-data
       (let* ((tag-list (when (eq (aref string 0) ?@)
                          (substring string 1
-                                    (if (>= emacs-major-version 28)
-                                        (string-search " " string)
-                                      (string-match " " string)))))
+                                    (string-search " " string))))
              (msg (make-erc-response :unparsed string :tags (when tag-list
                                                               (erc-parse-tags
                                                                tag-list))))
              (string (if tag-list
-                         (substring string (+ 1 (if (>= emacs-major-version 28)
-                                                    (string-search " " string)
-                                                  (string-match " " string))))
+                         (substring string (+ 1 (string-search " " string)))
                        string))
              (posn (if (eq (aref string 0) ?:)
-                       (if (>= emacs-major-version 28)
-                           (string-search " " string)
-                         (string-match " " string))
+                       (string-search " " string)
                      0)))
 
         (setf (erc-response.sender msg)
@@ -1036,9 +1030,7 @@ erc-parse-server-response
 
         (setf (erc-response.command msg)
               (let* ((bposn (string-match "[^ \n]" string posn))
-                     (eposn (if (>= emacs-major-version 28)
-                                (string-search " " string bposn)
-                              (string-match " " string bposn))))
+                     (eposn (string-search " " string bposn)))
                 (setq posn (and eposn
                                 (string-match "[^ \n]" string eposn)))
                 (substring string bposn eposn)))
@@ -1046,9 +1038,7 @@ erc-parse-server-response
         (while (and posn
                     (not (eq (aref string posn) ?:)))
           (push (let* ((bposn posn)
-                       (eposn (if (>= emacs-major-version 28)
-                                  (string-search " " string bposn)
-                                (string-match " " string bposn))))
+                       (eposn (string-search " " string bposn)))
                   (setq posn (and eposn
                                   (string-match "[^ \n]" string eposn)))
                   (substring string bposn eposn))
@@ -1667,9 +1657,7 @@ erc--parse-isupport-value
                      start (- (match-end 0) 3))
              (setq start (match-end 0))))
          v))
-     (if (if (>= emacs-major-version 28)
-             (string-search "," value)
-           (string-match-p "," value))
+     (if (string-search "," value)
          (split-string value ",")
        (list value)))))
 
diff --git a/lisp/erc/erc-compat.el b/lisp/erc/erc-compat.el
index e45b52f0c7..dec38df80a 100644
--- a/lisp/erc/erc-compat.el
+++ b/lisp/erc/erc-compat.el
@@ -26,6 +26,7 @@
 ;; This mostly defines stuff that cannot be worked around easily.
 
 ;;; Code:
+(require 'compat nil 'noerror)
 
 ;;;###autoload(autoload 'erc-define-minor-mode "erc-compat")
 (define-obsolete-function-alias 'erc-define-minor-mode
@@ -150,53 +151,6 @@ erc-subseq
 		 (setq i (1+ i) start (1+ start)))
 	       res))))))
 
-;;;; lisp/calendar/time-date.el
-
-(defun erc-compat--28-decoded-time-period (time)
-  "Interpret DECODED as a period and return its length in seconds.
-For computational purposes, years are 365 days long and months
-are 30 days long."
-  (+ (if (consp (decoded-time-second time))
-         ;; Fractional second.
-         (/ (float (car (decoded-time-second time)))
-            (cdr (decoded-time-second time)))
-       (or (decoded-time-second time) 0))
-     (* (or (decoded-time-minute time) 0) 60)
-     (* (or (decoded-time-hour time) 0) 60 60)
-     (* (or (decoded-time-day time) 0) 60 60 24)
-     (* (or (decoded-time-month time) 0) 60 60 24 30)
-     (* (or (decoded-time-year time) 0) 60 60 24 365)))
-
-(defmacro erc-compat--decoded-time-period (time)
-  (declare (indent defun))
-  (list (if (< emacs-major-version 28)
-            'erc-compat--28-decoded-time-period
-          'decoded-time-period)
-        time))
-
-;;;; lisp/minibuffer.el
-
-(defun erc-compat--28-format-prompt (prompt default &rest format-args)
-  (concat
-   (if (null format-args)
-       prompt
-     (apply #'format prompt format-args))
-   (and default
-        (or (not (stringp default))
-            (> (length default) 0))
-        (format " (default %s)"
-                (if (consp default)
-                    (car default)
-                  default)))
-   ": "))
-
-(defmacro erc-compat--format-prompt (&rest rest)
-  (declare (indent defun))
-  (cons (if (< emacs-major-version 28)
-            'erc-compat--28-format-prompt
-          'format-prompt)
-        rest))
-
 ;;;; lisp/emacs-lisp/subr-x.el
 
 (defmacro erc-compat--with-memoization (place &rest forms)
diff --git a/lisp/erc/erc-dcc.el b/lisp/erc/erc-dcc.el
index c8a66dd1d6..7a24acc433 100644
--- a/lisp/erc/erc-dcc.el
+++ b/lisp/erc/erc-dcc.el
@@ -191,9 +191,7 @@ erc-dcc-member
                   test (cadr (plist-member elt prop)))
             ;; if the property exists and is equal, we continue, else, try the
             ;; next element of the list
-            (or (and (eq prop :nick) (if (>= emacs-major-version 28)
-                                         (string-search "!" val)
-                                       (string-match "!" val))
+            (or (and (eq prop :nick) (string-search "!" val)
                      test (string-equal test val))
                 (and (eq prop :nick)
                      test val
@@ -520,8 +518,8 @@ erc-dcc-do-GET-command
          (filename (or file (plist-get elt :file) "unknown")))
     (if elt
         (let* ((file (read-file-name
-                      (erc-compat--format-prompt
-                        "Local filename" (file-name-nondirectory filename))
+                      (format-prompt "Local filename"
+                                     (file-name-nondirectory filename))
                       (or erc-dcc-get-default-directory
                           default-directory)
                       (expand-file-name (file-name-nondirectory filename)
@@ -659,13 +657,7 @@ erc-dcc-ctcp-query-send-regexp
 
 (define-inline erc-dcc-unquote-filename (filename)
   (inline-quote
-   (if (>= emacs-major-version 28)
-       (string-replace
-        "\\\\" "\\"
-        (string-replace "\\\"" "\"" ,filename))
-     (replace-regexp-in-string
-      "\\\\\\\\" "\\"
-      (replace-regexp-in-string "\\\\\"" "\"" ,filename t t) t t))))
+   (string-replace "\\\\" "\\" (string-replace "\\\"" "\"" ,filename))))
 
 (defun erc-dcc-handle-ctcp-send (proc query nick login host to)
   "This is called if a CTCP DCC SEND subcommand is sent to the client.
diff --git a/lisp/erc/erc-speedbar.el b/lisp/erc/erc-speedbar.el
index 5b06c21612..19113c5aad 100644
--- a/lisp/erc/erc-speedbar.el
+++ b/lisp/erc/erc-speedbar.el
@@ -139,9 +139,7 @@ erc-speedbar-server-buttons
 	t))))
 
 (defun erc-speedbar-expand-server (text server indent)
-  (cond ((if (>= emacs-major-version 28)
-             (string-search "+" text)
-           (string-match "\\+" text))
+  (cond ((string-search "+" text)
 	 (speedbar-change-expand-button-char ?-)
 	 (if (speedbar-with-writable
 	       (save-excursion
@@ -150,9 +148,7 @@ erc-speedbar-expand-server
 	     (speedbar-change-expand-button-char ?-)
 	   (speedbar-change-expand-button-char ??)))
 	(;; we have to contract this node
-         (if (>= emacs-major-version 28)
-             (string-search "-" text)
-           (string-match "-" text))
+         (string-search "-" text)
 	 (speedbar-change-expand-button-char ?+)
 	 (speedbar-delete-subblock indent))
 	(t (error "Ooops... not sure what to do")))
@@ -189,9 +185,7 @@ erc-speedbar-expand-channel
   "For the line matching TEXT, in CHANNEL, expand or contract a line.
 INDENT is the current indentation level."
   (cond
-   ((if (>= emacs-major-version 28)
-        (string-search "+" text)
-      (string-match "\\+" text))
+   ((string-search "+" text)
     (speedbar-change-expand-button-char ?-)
     (speedbar-with-writable
      (save-excursion
@@ -240,9 +234,7 @@ erc-speedbar-expand-channel
 	     (speedbar-with-writable
 	      (dolist (entry names)
 		(erc-speedbar-insert-user entry ?+ (1+ indent))))))))))
-   ((if (>= emacs-major-version 28)
-        (string-search "-" text)
-      (string-match "-" text))
+   ((string-search "-" text)
     (speedbar-change-expand-button-char ?+)
     (speedbar-delete-subblock indent))
    (t (error "Ooops... not sure what to do")))
@@ -293,9 +285,7 @@ erc-speedbar-update-channel
 	(erc-speedbar-expand-channel "+" buffer 1)))))
 
 (defun erc-speedbar-expand-user (text token indent)
-  (cond ((if (>= emacs-major-version 28)
-             (string-search "+" text)
-           (string-match "\\+" text))
+  (cond ((string-search "+" text)
 	 (speedbar-change-expand-button-char ?-)
 	 (speedbar-with-writable
 	   (save-excursion
@@ -318,9 +308,7 @@ erc-speedbar-expand-user
 		  nil nil nil nil
 		  info nil nil nil
 		  (1+ indent)))))))
-	((if (>= emacs-major-version 28)
-             (string-search "-" text)
-           (string-match "-" text))
+	((string-search "-" text)
 	 (speedbar-change-expand-button-char ?+)
 	 (speedbar-delete-subblock indent))
 	(t (error "Ooops... not sure what to do")))
diff --git a/lisp/erc/erc.el b/lisp/erc/erc.el
index 508f0e9620..3a58a0975e 100644
--- a/lisp/erc/erc.el
+++ b/lisp/erc/erc.el
@@ -13,7 +13,7 @@
 ;;               Michael Olson ([email protected])
 ;;               Kelvin White ([email protected])
 ;; Version: 5.4.1
-;; Package-Requires: ((emacs "27.1"))
+;; Package-Requires: ((emacs "27.1") (compat "28.1.1.0"))
 ;; Keywords: IRC, chat, client, Internet
 ;; URL: https://www.gnu.org/software/emacs/erc.html
 
@@ -3211,7 +3211,7 @@ erc--read-time-period
                     (wrong-type-argument nil))))
         (unless time
           (user-error "%s is not a valid time period" period))
-        (erc-compat--decoded-time-period time))))))
+        (decoded-time-period time))))))
 
 (defun erc-cmd-IGNORE (&optional user)
   "Ignore USER.  This should be a regexp matching nick!user@host.
@@ -3521,9 +3521,7 @@ erc--valid-local-channel-p
   "Non-nil when channel is server-local on a network that allows them."
   (and-let* (((eq ?& (aref channel 0)))
              (chan-types (erc--get-isupport-entry 'CHANTYPES 'single))
-             ((if (>= emacs-major-version 28)
-                  (string-search "&" chan-types)
-                (string-match-p "&" chan-types))))))
+             ((string-search "&" chan-types)))))
 
 (defun erc-cmd-JOIN (channel &optional key)
   "Join the channel given in CHANNEL, optionally with KEY.
@@ -4482,7 +4480,7 @@ erc-join-channel
           (table (when (erc-server-buffer-live-p)
                    (set-buffer (process-buffer erc-server-process))
                    erc-channel-list)))
-      (completing-read (erc-compat--format-prompt "Join channel" chnl)
+      (completing-read (format-prompt "Join channel" chnl)
                        table nil nil nil nil chnl))
     (when (or current-prefix-arg erc-prompt-for-channel-key)
       (read-string "Channel key (RET for none): "))))
@@ -7006,21 +7004,12 @@ erc-update-mode-line-buffer
                                   (fill-region (point-min) (point-max))
                                   (buffer-string))))
                  (setq header-line-format
-                       (if (>= emacs-major-version 28)
-                           (string-replace
-                            "%"
-                            "%%"
-                            (if face
-                                (propertize header 'help-echo help-echo
-                                            'face face)
-                              (propertize header 'help-echo help-echo)))
-                         (replace-regexp-in-string
-                          "%"
-                          "%%"
-                          (if face
-                              (propertize header 'help-echo help-echo
-                                          'face face)
-                            (propertize header 'help-echo help-echo)))))))
+                       (string-replace
+                        "%"
+                        "%%"
+                        (if face
+                            (propertize header 'help-echo help-echo 'face face)
+                          (propertize header 'help-echo help-echo))))))
               (t (setq header-line-format
                        (if face
                            (propertize header 'face face)
@@ -7305,9 +7294,7 @@ erc-message-english-PART
               nick user host channel
               (if (not (string= reason ""))
                   (format ": %s"
-                          (if (>= emacs-major-version 28)
-                              (string-replace "%" "%%" reason)
-                            (replace-regexp-in-string "%" "%%" reason)))
+                          (string-replace "%" "%%" reason))
                 "")))))
 
 
-- 
2.36.1