* lisp/select.el (gui-selection-exists-p-alist): New method.

* lisp/menu-bar.el (menu-bar-edit-menu, clipboard-yank):
* lisp/simple.el (deactivate-mark): Use it.
* lisp/term/x-win.el (gui-selection-exists-p):
* lisp/term/w32-win.el (gui-selection-exists-p):
* lisp/term/pc-win.el (gui-selection-exists-p):
* lisp/term/ns-win.el (gui-selection-exists-p): Provide a backend instance.

lisp/ChangeLog

@@ -1,3 +1,13 @@
+2014-10-10  Stefan Monnier  <monnier@iro.umontreal.ca>
+
+	* select.el (gui-selection-exists-p-alist): New method.
+	* menu-bar.el (menu-bar-edit-menu, clipboard-yank):
+	* simple.el (deactivate-mark): Use it.
+	* term/x-win.el (gui-selection-exists-p):
+	* term/w32-win.el (gui-selection-exists-p):
+	* term/pc-win.el (gui-selection-exists-p):
+	* term/ns-win.el (gui-selection-exists-p): Provide a backend instance.
+
 2014-10-10  Glenn Morris  <rgm@gnu.org>
 
 	* info.el (Info-fontify-maximum-menu-size): Bump to 400k.  (Bug#16227)

lisp/menu-bar.el

@@ -470,17 +470,14 @@
                        [paste-from-menu])
       ;; ns-win.el said: Change text to be more consistent with
       ;; surrounding menu items `paste', etc."
-      `(menu-item ,(if (featurep 'ns) "Select and Paste"
-                     "Paste from Kill Menu") yank-menu
+      `(menu-item ,(if (featurep 'ns) "Select and Paste" "Paste from Kill Menu")
+                  yank-menu
                   :enable (and (cdr yank-menu) (not buffer-read-only))
                   :help "Choose a string from the kill ring and paste it"))
     (bindings--define-key menu [paste]
       '(menu-item "Paste" yank
                   :enable (and (or
-                                ;; Emacs compiled --without-x (or --with-ns)
-                                ;; doesn't have x-selection-exists-p.
-                                (and (fboundp 'x-selection-exists-p)
-                                     (x-selection-exists-p 'CLIPBOARD))
+                                (gui-call gui-selection-exists-p 'CLIPBOARD)
                                 (if (featurep 'ns) ; like paste-from-menu
                                     (cdr yank-menu)
                                   kill-ring))
@@ -537,9 +534,8 @@
      '(and mark-active (not buffer-read-only)))
 (put 'clipboard-kill-ring-save 'menu-enable 'mark-active)
 (put 'clipboard-yank 'menu-enable
-     '(and (or (not (fboundp 'x-selection-exists-p))
-	       (x-selection-exists-p)
-	       (x-selection-exists-p 'CLIPBOARD))
+     '(and (or (gui-call gui-selection-exists-p 'PRIMARY)
+	       (gui-call gui-selection-exists-p 'CLIPBOARD))
  	   (not buffer-read-only)))
 
 (defun clipboard-yank ()

lisp/select.el

@@ -235,9 +235,14 @@ Called with one argument: (SELECTION)")
 Called with one argument: (SELECTION).
 The arg should be the name of the selection in question, typically one of
 the symbols `PRIMARY', `SECONDARY', or `CLIPBOARD'.
-(Those are literal upper-case symbol names, since that's what X expects.)
-For convenience, the symbol nil is the same as `PRIMARY',
-and t is the same as `SECONDARY'.")
+(Those are literal upper-case symbol names, since that's what X expects.)")
+
+(gui-method-declare gui-selection-exists-p #'ignore
+  "Whether there is an owner for the given X Selection.
+Called with one argument: (SELECTION).
+The arg should be the name of the selection in question, typically one of
+the symbols `PRIMARY', `SECONDARY', or `CLIPBOARD'.
+(Those are literal upper-case symbol names, since that's what X expects.)")
 
 (defun gui-set-selection (type data)
   "Make an X selection of type TYPE and value DATA.

lisp/simple.el

@@ -4497,8 +4497,6 @@ a mistake; see the documentation of `set-mark'."
     (signal 'mark-inactive nil)))
 
 ;; Behind display-selections-p.
-(declare-function x-selection-exists-p "xselect.c"
-                  (&optional selection terminal))
 
 (defun deactivate-mark (&optional force)
   "Deactivate the mark.
@@ -4529,7 +4527,7 @@ run `deactivate-mark-hook'."
 	    ;; deactivation should not clobber it (Bug#11772).
 	    ((and (/= (region-beginning) (region-end))
 		  (or (gui-call gui-selection-owner-p 'PRIMARY)
-		      (null (gui-selection-exists-p 'PRIMARY))))
+		      (null (gui-call gui-selection-exists-p 'PRIMARY))))
 	     (gui-set-selection 'PRIMARY
                                 (funcall region-extract-function nil)))))
     (when mark-active (force-mode-line-update)) ;Refresh toolbar (bug#16382).

lisp/term/ns-win.el

@@ -961,6 +961,7 @@ See the documentation of `create-fontset-from-fontset-spec' for the format.")
 (gui-method-define gui-own-selection ns #'ns-own-selection-internal)
 (gui-method-define gui-disown-selection ns #'ns-disown-selection-internal)
 (gui-method-define gui-selection-owner-p ns #'ns-selection-owner-p)
+(gui-method-define gui-selection-exists-p ns #'x-selection-exists-p)
 (gui-method-define gui-get-selection ns #'x-get-selection-internal) ;FIXME:name!
 
 (provide 'ns-win)

lisp/term/pc-win.el

@@ -228,6 +228,7 @@ Consult the selection.  Treat empty strings as if they were unset."
         (w16-get-clipboard-data))))
 
 ;; gui-selection-owner-p is used in simple.el.
+(gui-method-define gui-selection-exists-p pc #'x-selection-exists-p)
 (gui-method-define gui-selection-owner-p pc #'w16-selection-owner-p)
 (defun w16-selection-owner-p (_selection)
   ;; FIXME: Other systems don't obey gui-select-enable-clipboard here.

lisp/term/w32-win.el

@@ -420,6 +420,7 @@ Consult the selection.  Treat empty strings as if they were unset."
                    (lambda (selection)
                      (and (memq selection '(nil PRIMARY SECONDARY))
                           (get 'x-selections (or selection 'PRIMARY)))))
+(gui-method-define gui-selection-exists-p w32 #'x-selection-exists-p)
 
 ;; The "Windows" keys on newer keyboards bring up the Start menu
 ;; whether you want it or not - make Emacs ignore these keystrokes

lisp/term/x-win.el

@@ -1473,6 +1473,7 @@ This returns an error if any Emacs frames are X frames."
 (gui-method-define gui-own-selection x #'x-own-selection-internal)
 (gui-method-define gui-disown-selection x #'x-disown-selection-internal)
 (gui-method-define gui-selection-owner-p x #'x-selection-owner-p)
+(gui-method-define gui-selection-exists-p x #'x-selection-exists-p)
 (gui-method-define gui-get-selection x #'x-get-selection-internal)
 
 ;; Initiate drag and drop