From: Dmitry Gutov <dgutov@yandex.ru>
Date: Sat, 3 Jan 2015 14:02:04 +0000 (+0200)
Subject: Only show "Back" when the marker stack is non-empty
X-Git-Tag: emacs-25.0.90~2611^2~12
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=8bef7b6ad1775124eeed81acf46551c0fc3aa75e;p=emacs.git

Only show "Back" when the marker stack is non-empty

* lisp/menu-bar.el (menu-bar-goto-menu): Use it.

* lisp/progmodes/xref.el (xref-marker-stack-empty-p): New function.
---

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 34e22af92a9..49640f89055 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,9 @@
+2015-01-03  Dmitry Gutov  <dgutov@yandex.ru>
+
+	* progmodes/xref.el (xref-marker-stack-empty-p): New function.
+
+	* menu-bar.el (menu-bar-goto-menu): Use it.
+
 2015-01-03  Dmitry Gutov  <dgutov@yandex.ru>
 
 	* progmodes/xref.el (xref--window-configuration): New variable.
diff --git a/lisp/menu-bar.el b/lisp/menu-bar.el
index 7d7e4660fb5..67cb3273d23 100644
--- a/lisp/menu-bar.el
+++ b/lisp/menu-bar.el
@@ -381,6 +381,7 @@
 
     (bindings--define-key menu [xref-pop]
       '(menu-item "Back" xref-pop-marker-stack
+                  :visible (not (xref-marker-stack-empty-p))
                   :help "Back to the position of the last search"))
 
     (bindings--define-key menu [xref-apropos]
diff --git a/lisp/progmodes/xref.el b/lisp/progmodes/xref.el
index cb331e1c833..7bc6500a8de 100644
--- a/lisp/progmodes/xref.el
+++ b/lisp/progmodes/xref.el
@@ -301,6 +301,10 @@ backward."
       (let ((marker (ring-remove ring)))
         (set-marker marker nil nil)))))
 
+(defun xref-marker-stack-empty-p ()
+  "Return t if the marker stack is empty; nil otherwise."
+  (ring-empty-p xref--marker-ring))
+
 
 (defun xref--goto-location (location)
   "Set buffer and point according to xref-location LOCATION."