bug#74934: 30.0.92; Unexpected behavior by which-function-mode in erc-mode buffers

[Anush V]

Hello Maintainers,

I guess this is probably unexpected behavior by which-function-mode in erc-mode
buffers and so reporting this.


steps to reproduce:
emacs --no-init
M-x erc
;; join some channel.
M-x which-function-mode

Current behavior:
In erc buffers, which-function-mode displays either "[n/a]" or a string based on
the chat history in the mode line.

Expected behavior:
which-function-mode shouldn’t be adding any string to mode line in erc buffers


Thank you for your time!

* * *

In GNU Emacs 30.0.92 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.41, cairo
version 1.18.0)
Windowing system distributor 'The X.Org Foundation', version 11.0.12101014
System Description: Guix System

Configured using:
 'configure
 
CONFIG_SHELL=/gnu/store/3jhfhxdf6v5ms10x5zmnl166dh3yhbr1-bash-minimal-5.1.16/bin/bash
 SHELL=/gnu/store/3jhfhxdf6v5ms10x5zmnl166dh3yhbr1-bash-minimal-5.1.16/bin/bash 
--prefix=/gnu/store/dgpfiflaxb8j33jcbqk29wadcykajl51-emacs-next-30.0.92-0.881d593
 --enable-fast-install --with-cairo --with-modules 
--with-native-compilation=aot --disable-build-details'

Configured features:
ACL CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GPM GSETTINGS HARFBUZZ JPEG LCMS2
LIBOTF LIBSELINUX LIBSYSTEMD LIBXML2 M17N_FLT MODULES NATIVE_COMP NOTIFY INOTIFY
PDUMPER PNG RSVG SECCOMP SOUND SQLITE3 THREADS TIFF TOOLKIT_SCROLL_BARS
TREE_SITTER X11 XDBE XIM XINPUT2 XPM GTK3 ZLIB

--
Regards,
Anush V