bug#64699: Invalid key definition for keymap-set-after

[uzibalqa via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

It is recommended that 'keymap-set-after' is used instead of 'define-key-after'.

But replacing

  (defvar mcp-kdf (make-sparse-keymap "MCP"))
  (define-key-after global-map
    [menu-bar mcp-topm] (cons "MCP" mcp-kdf) 'tools)

with 

  (defvar mcp-kdf (make-sparse-keymap "MCP"))
  (keymap-set-after global-map
    [menu-bar mcp-topm] (cons "MCP" mcp-kdf) 'tools)

gives the following error

(error "[menu-bar mcp-topm] is not a valid key definition;...")
  signal(error ("[menu-bar mcp-topm] is not a valid key definition;..."))
  error("%S is not a valid key definition; see `key-valid-p..." [menu-bar mcp-topm])
  keymap--check([menu-bar mcp-topm])
  keymap-set-after((keymap #^[nil nil keymap 
#^^[3 0 set-mark-command move-beginning-of-line backward-char mode-specific-command-prefix delete-char move-end-of-line forward-char keyboard-quit help-command indent-for-tab-command electric-newline-and-maybe-indent kill-line recenter-top-bottom newline next-line open-line previous-line quoted-insert isearch-backward isearch-forward transpose-chars universal-argument scroll-up-command kill-region Control-X-prefix yank suspend-frame ESC-prefix toggle-input-method abort-recursive-edit nil undo self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command ...] #^^[1 0 #^^[2 0 
#^^[3 0 set-mark-command move-beginning-of-line backward-char mode-specific-command-prefix delete-char move-end-of-line forward-char keyboard-quit help-command indent-for-tab-command electric-newline-and-maybe-indent kill-line recenter-top-bottom newline next-line open-line previous-line quoted-insert isearch-backward isearch-forward transpose-chars universal-argument scroll-up-command kill-region Control-X-prefix yank suspend-frame ESC-prefix toggle-input-method abort-recursive-edit nil undo self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command ...] self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command] self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command] self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command self-insert-command ...] (67108908 . text-scale-decrease) (67108910 . text-scale-increase) (f5 . modus-themes-toggle) (paste . clipboard-yank) (copy . clipboard-kill-ring-save) (cut . clipboard-kill-region) (f18 . clipboard-yank) (f16 . clipboard-kill-ring-save) (f20 . clipboard-kill-region) (C-wheel-down . mouse-wheel-text-scale) (C-wheel-up . mouse-wheel-text-scale) (C-mouse-5 . mouse-wheel-text-scale) (C-mouse-4 . mouse-wheel-text-scale) (C-M-wheel-down . mouse-wheel-global-text-scale) (C-M-wheel-up . mouse-wheel-global-text-scale) (C-M-mouse-5 . mouse-wheel-global-text-scale) (C-M-mouse-4 . mouse-wheel-global-text-scale) (M-wheel-right . mwheel-scroll) (M-wheel-left . mwheel-scroll) (M-wheel-down . mwheel-scroll) (M-wheel-up . mwheel-scroll) (M-mouse-7 . mwheel-scroll) (M-mouse-6 . mwheel-scroll) (M-mouse-5 . mwheel-scroll) (M-mouse-4 . mwheel-scroll) (S-wheel-right . mwheel-scroll) (S-wheel-left . mwheel-scroll) (S-wheel-down . mwheel-scroll) (S-wheel-up . mwheel-scroll) (S-mouse-7 . mwheel-scroll) (S-mouse-6 . mwheel-scroll) (S-mouse-5 . mwheel-scroll) (S-mouse-4 . mwheel-scroll) (wheel-right . mwheel-scroll) (wheel-left . mwheel-scroll) (wheel-down . mwheel-scroll) ...) [menu-bar mcp-topm] ("MCP" keymap "MCP") tools)
  mcp-menubar()
  eval-buffer(#<buffer  *load*-661928> nil "/home/hagbard/Opstk/bin/gungadin-1.0/typex/oktant/..." nil t)  ; Reading at buffer position 10068
  load-with-code-conversion("/home/hagbard/Opstk/bin/gungadin-1.0/typex/oktant/..." "/home/hagbard/Opstk/bin/gungadin-1.0/typex/oktant/..." nil t)
  require(mcp)