Subject: Updated patch

From: Olivier Certner <[email-masked]>
Date: Tue, 06 Jul 2021 14:06:32 +0200

Patch slightly edited (commit message) and rebased on top of a recent 
'master'. Ready to apply. Easy to backport to 27 as well.

-- 
Olivier Certner

>From c21f772f35fad8f80d951048ff134387e30ca076 Mon Sep 17 00:00:00 2001
From: Olivier Certner <[email-masked]>
Date: Tue, 6 Jul 2021 10:51:57 +0200
Subject: [PATCH] ERC: Unbreak ERC's IBuffer's custom displays (Bug#44100)

* lisp/erc/erc-ibuffer.el (erc-modified): Don't use `length' on dotted
lists (and not even to test if there is more than one element, for
that matter).  Use `cdr' instead.
---
 lisp/erc/erc-ibuffer.el | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lisp/erc/erc-ibuffer.el b/lisp/erc/erc-ibuffer.el
index 22336ede21..31e59a6d3e 100644
--- a/lisp/erc/erc-ibuffer.el
+++ b/lisp/erc/erc-ibuffer.el
@@ -73,7 +73,7 @@ erc-modified
 	   erc-track-mode)
       (let ((entry (assq (current-buffer) erc-modified-channels-alist)))
 	(if entry
-	    (if (> (length entry) 1)
+	    (if (cdr entry)
 		(cond ((eq 'pal (nth 1 entry))
 		       (string erc-ibuffer-pal-char))
 		      ((eq 'fool (nth 1 entry))
-- 
2.30.0