bug#81642: [PATCH] rcirc: Allow UnrealIRCd CAP whitespace quirk

> From: Jaidyn Ann <[email protected]>
> Date: Mon, 17 Aug 2026 02:42:20 +0000
> 
> Tags: patch
> 
> Hi there,
> 
> I've got a minor minor bugfix.
> 
> Trying to connect to Slashnet recently, I found rcirc couldn't
> get out of registration because of a weird quirk with their
> server's CAP messages: Names sometimes have trailing whitespace,
> so rcirc doesn't catch that it's been properly ACKd by the server.
> 
> Where `cap` parsed out of the server's mesage is
> "multi-prefix " and rcirc-requested-capabilities only contains
> "multi-prefix", this won't work:
> `(delete cap rcirc-requested-capabilities)`
> 
> String-trimming `cap` there fixes it.

Thanks, let me add the relevant individuals to this discussion.

> In GNU Emacs 30.2 (build 1, aarch64-unknown-linux-gnu, GTK+ Version
>  3.24.51, cairo version 1.18.4) of 2025-12-01, modified by Debian built
>  on sbuild
> Windowing system distributor 'The X.Org Foundation', version 11.0.12101021
> System Description: Debian GNU/Linux forky/sid
> 
> Configured using:
>  'configure --build aarch64-linux-gnu --prefix=/usr
>  --sharedstatedir=/var/lib --libexecdir=/usr/libexec
>  --localstatedir=/var/lib --infodir=/usr/share/info
>  --mandir=/usr/share/man --with-libsystemd --with-pop=yes
>  --enable-locallisppath=/etc/emacs:/usr/local/share/emacs/30.2/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/30.2/site-lisp:/usr/share/emacs/site-lisp
>  --with-sound=alsa --without-gconf --with-mailutils --build
>  aarch64-linux-gnu --prefix=/usr --sharedstatedir=/var/lib
>  --libexecdir=/usr/libexec --localstatedir=/var/lib
>  --infodir=/usr/share/info --mandir=/usr/share/man --with-libsystemd
>  --with-pop=yes
>  --enable-locallisppath=/etc/emacs:/usr/local/share/emacs/30.2/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/30.2/site-lisp:/usr/share/emacs/site-lisp
>  --with-sound=alsa --without-gconf --with-mailutils --with-cairo
>  --with-x=yes --with-x-toolkit=gtk3 --with-toolkit-scroll-bars
>  'CFLAGS=-g -O2 -Werror=implicit-function-declaration
>  -ffile-prefix-map=/build/reproducible-path/emacs-30.2+1=. -fstack-protector-strong
>  -fstack-clash-protection -Wformat -Werror=format-security
>  -mbranch-protection=standard -Wall' 'CPPFLAGS=-Wdate-time
>  -D_FORTIFY_SOURCE=2' LDFLAGS=-Wl,-z,relro'
> 
> >From cd424bb53a87c40f6570ecd4d5cd83eedce5448f Mon Sep 17 00:00:00 2001
> From: Jaidyn Ann <[email protected]>
> Date: Sun, 16 Aug 2026 21:32:03 -0500
> Subject: [PATCH] rcirc: Allow UnrealIRCd CAP whitespace quirk
> 
> (rcirc-handler-CAP): Trim received capability
> names, since some servers *cough* add trailing whitespace.
> ---
>  lisp/net/rcirc.el | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/lisp/net/rcirc.el b/lisp/net/rcirc.el
> index a7cf5c0db37..cd1638c2d1f 100644
> --- a/lisp/net/rcirc.el
> +++ b/lisp/net/rcirc.el
> @@ -3820,7 +3820,7 @@ ARGS should have the form (USER SUBCOMMAND . ARGUMENTS).  PROCESS
>  is the process object for the current connection."
>    (with-rcirc-process-buffer process
>      (let ((subcmd (cadr args)))
> -      (dolist (cap (cddr args))
> +      (dolist (cap (mapcar 'string-trim (cddr args)))
>          (cond ((string= subcmd "ACK")
>                 (push (intern (downcase cap)) rcirc-acked-capabilities)
>                 (setq rcirc-requested-capabilities
> -- 
> 2.53.0
>