bug#6944: Paste in Edit menu not active at start

[Chong Yidong]

Eli Zaretskii <eliz@gnu.org> writes:

>   (define-key menu-bar-edit-menu [paste]
>     `(menu-item ,(purecopy "Paste") yank
>               :enable (and (or
>                             ;; Emacs compiled --without-x doesn't have
>                             ;; x-selection-exists-p.
>                             (and (fboundp 'x-selection-exists-p)
>                                  (x-selection-exists-p))
>                             kill-ring)
>                            (not buffer-read-only))
>
> I can easily fix that with an MS-Windows specific change, but I'm
> actually surprised we don't call (x-selection-exists-p 'CLIPBOARD)
> here: isn't C-y supposed to yank from the clipboard, not from PRIMARY?
> If we use 'CLIPBOARD, the code will work on Windows without any
> changes.

Yes, please make the change.  This looks like an oversight.