Merge from emacs-24; up to 2012-12-29T12:57:49Z!fgallina@gnu.org

2 files changed, 6 insertions, 2 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 8327fb03b4e..9e746b25146 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,5 +1,7 @@
 2013-07-03  Glenn Morris  <rgm@gnu.org>
 
+        * subr.el (y-or-n-p): Handle empty prompts.  (Bug#14770)
+
         Make info-xref checks case-sensitive by default
         * info.el (Info-find-node, Info-find-in-tag-table)
         (Info-find-node-in-buffer, Info-find-node-2, Info-goto-node):
diff --git a/lisp/subr.el b/lisp/subr.el
index b8a62023805..55cdcb45f50 100644
--- a/lisp/subr.el
+++ b/lisp/subr.el
@@ -2240,7 +2240,8 @@ is nil and `use-dialog-box' is non-nil."
     (cond
      (noninteractive
       (setq prompt (concat prompt
-                           (if (eq ?\s (aref prompt (1- (length prompt))))
+                           (if (or (zerop (length prompt))
+                                   (eq ?\s (aref prompt (1- (length prompt)))))
                                "" " ")
                            "(y or n) "))
       (let ((temp-prompt prompt))
@@ -2257,7 +2258,8 @@ is nil and `use-dialog-box' is non-nil."
             (x-popup-dialog t `(,prompt ("Yes" . act) ("No" . skip)))))
      (t
       (setq prompt (concat prompt
-                           (if (eq ?\s (aref prompt (1- (length prompt))))
+                           (if (or (zerop (length prompt))
+                                   (eq ?\s (aref prompt (1- (length prompt)))))
                                "" " ")
                            "(y or n) "))
       (while