bug#66021: 30.0.50; error from C-h k with closure

[Gerd Möllmann]

With emacs -Q, evaluate

  (keymap-global-set "<f2>" (lambda () (interactive) (message "<f2>")))

then C-h k and press f2.  This signals an error

  help-fns--signature: Wrong type argument: symbolp, (closure ...


In GNU Emacs 30.0.50 (build 4, x86_64-apple-darwin20.6.0, NS
 appkit-2022.70 Version 11.7.10 (Build 20G1427)) of 2023-09-15 built on
 Pro.fritz.box
Repository revision: 1442f4043a761e9bdeeb4e1fbe9822c2987c1502
Repository branch: master
Windowing system distributor 'Apple', version 10.3.2022
System Description:  macOS 11.7.10