Right click on category fails with Emacs 27.1 and later

[hdasch]

With emacs 27.1 and later, following the demonstration in the README, a mouse right click on a category results in a wrong-type-arugment error. This is a regression in Emacs, not an issue with log4slime. I mention it here to leave breadcrumbs for anyone else encountering the issue.

The issue has been reported to debbugs here: https://lists.gnu.org/archive/html/bug-gnu-emacs/2021-08/msg00753.html

Until a fix is available, this dubious bit of code should provide as a workaround:

(eval-after-load 'log4slime
  '(when (and
          (version<= "27.1" emacs-version)
          (version< emacs-version "28.0"))
    (defun easy-menu-do-define (symbol maps doc menu)
     ;; We can't do anything that might differ between Emacs dialects in
     ;; `easy-menu-define' in order to make byte compiled files
     ;; compatible.  Therefore everything interesting is done in this
     ;; function.
     (let ((keymap (easy-menu-create-menu (car menu) (cdr menu))))
      (when symbol
       (set symbol keymap)
       (defalias symbol
         `(lambda (event) ,doc (interactive "@e")
            ;; FIXME: XEmacs uses popup-menu which calls the binding
            ;; while x-popup-menu only returns the selection.
            (x-popup-menu event
             (or (and (symbolp ,symbol)
                  (funcall
                   (or (plist-get (get ,symbol 'menu-prop)
                        :filter)
                    #'identity)
                   (symbol-function ,symbol)))
              ,symbol))))
       ;; These symbols are commands, but not interesting for users
       ;; to `M-x TAB'.
       (function-put symbol 'completion-predicate #'ignore))
      (dolist (map (if (keymapp maps) (list maps) maps))
       (define-key map
         (vector 'menu-bar (if (symbolp (car menu))
                               (car menu)
                             ;; If a string, then use the downcased
                             ;; version for greater backwards compatibility.
                             (intern (downcase (car menu)))))
         (easy-menu-binding keymap (car menu))))))

    (log4slime-redefine-menus)))

[hdasch]

Fixed for Emacs 28 with commit bf55b5ac17cd5a40ad5ff2e25af7e050602180bb.