emacs-29 75f26646d4 3/7: ; Be nicer when updating browse-url var in erc-compat

[F. Jason Park]

branch: emacs-29
commit 75f26646d4a569cfb485de4baddcda66ff44b2c3
Author: F. Jason Park <jp@neverwas.me>
Commit: F. Jason Park <jp@neverwas.me>

    ; Be nicer when updating browse-url var in erc-compat
    
    * lisp/erc/erc-compat.el: Be more cautious about modifying
    `browse-url-default-handlers' when loading erc-compat on Emacs 28.  A
    user may have already added an entry for irc:// URLs before loading
    `erc-compat'.
---
 lisp/erc/erc-compat.el | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/lisp/erc/erc-compat.el b/lisp/erc/erc-compat.el
index bd93254758..77625398ab 100644
--- a/lisp/erc/erc-compat.el
+++ b/lisp/erc/erc-compat.el
@@ -391,8 +391,11 @@ If START or END is negative, it counts from the end."
 
 (cond ((fboundp 'browse-url-irc)) ; 29
       ((boundp 'browse-url-default-handlers) ; 28
-       (cl-pushnew '("\\`irc6?s?://" . erc-compat--29-browse-url-irc)
-                   browse-url-default-handlers))
+       (setf (alist-get "\\`irc6?s?://" browse-url-default-handlers
+                        nil nil (lambda (a _)
+                                  (and (stringp a)
+                                       (string-match-p a "irc://localhost"))))
+             #'erc-compat--29-browse-url-irc))
       ((boundp 'browse-url-browser-function) ; 27
        (require 'browse-url)
        (let ((existing browse-url-browser-function))