bug#22955: 25.1.50; *Help* xref for generic methods broken

[Dmitry Gutov <dgutov@yandex.ru>]

On 03/09/2016 06:16 AM, Eric Abrahamsen wrote:
>
> If you `describe-function' on a generic method, the resulting *Help*
> buffer shows the various implementations correctly. However,
> clicking/RET on the implementation links fails with:

Have you tried it with a build from emacs-25?

It seems to work fine here, at least for xref-backend-definitions and 
xref-backend-apropos.

> Debugger entered--Lisp error: (wrong-number-of-arguments (lambda (fun file) (require (quote find-func)) (if (eq file (quote C-source)) (progn (setq file (help-C-file-name (indirect-function fun) (quote fun))))) (let ((location (find-function-search-for-symbol fun nil file))) (my-find-symbol-switch-to-buffer (car location)) (if (cdr location) (goto-char (cdr location)) (message "Unable to find location in file")))) 3)
>   help-do-xref(nil (lambda (fun file) (require (quote find-func)) (if (eq file (quote C-source)) (progn (setq file (help-C-file-name (indirect-function fun) (quote fun))))) (let ((location (find-function-search-for-symbol fun nil file))) (my-find-symbol-switch-to-buffer (car location)) (if (cdr location) (goto-char (cdr location)) (message "Unable to find location in file")))) ((bbdb-db-load bbdb-db) "/home/eric/.emacs.d/bbdb/lisp/bbdb.el" cl-defmethod))
>   help-button-action(#<marker (moves after insertion) at 276 in *Help*>)
>   button-activate(#<marker (moves after insertion) at 276 in *Help*> nil)
>   push-button(276)
>   funcall-interactively(push-button 276)
>   call-interactively(push-button nil nil)
>   command-execute(push-button)

What's that my-find-symbol-switch-to-buffer in the backtrace?