emacs-27 d83cc05: Fix error in ERC when 'erc-server-coding-system' is customized

[Eli Zaretskii]

branch: emacs-27
commit d83cc05a73645f23558590e0415ecb7d5ae2d02d
Author: Eli Zaretskii <address@hidden>
Commit: Eli Zaretskii <address@hidden>

    Fix error in ERC when 'erc-server-coding-system' is customized
    
    * lisp/erc/erc-backend.el (erc-split-line): Handle the case where
    'erc-coding-system-for-target' returns a coding-system's symbol.
    (Bug#40914)
---
 lisp/erc/erc-backend.el | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lisp/erc/erc-backend.el b/lisp/erc/erc-backend.el
index 0e3495e..526e854 100644
--- a/lisp/erc/erc-backend.el
+++ b/lisp/erc/erc-backend.el
@@ -466,7 +466,8 @@ If this is set to nil, never try to reconnect."
 The length is specified in `erc-split-line-length'.
 
 Currently this is called by `erc-send-input'."
-  (let ((charset (car (erc-coding-system-for-target nil))))
+  (let* ((coding (erc-coding-system-for-target nil))
+         (charset (if (consp coding) (car coding) coding)))
     (with-temp-buffer
       (insert longline)
       ;; The line lengths are in octets, not characters (because these