Add a utility function buffer-narrowed-p, and use it.

* lisp/subr.el (buffer-narrowed-p): New function.

* lisp/ses.el (ses-widen):
* lisp/simple.el (count-words--buffer-message):
* lisp/net/browse-url.el (browse-url-of-buffer): Use it

* lisp/simple.el (count-words-region): Don't signal an error if there
is a non-nil prefix arg and the mark is not set.

* doc/lispref/positions.texi (Narrowing): Document buffer-narrowed-p.

9 files changed, 41 insertions, 22 deletions

diff --git a/doc/lispref/ChangeLog b/doc/lispref/ChangeLog
index bd21100dd4c..179f81990a7 100644
--- a/doc/lispref/ChangeLog
+++ b/doc/lispref/ChangeLog
@@ -1,5 +1,7 @@
 2012-09-07  Chong Yidong  <cyd@gnu.org>
 
+        * positions.texi (Narrowing): Document buffer-narrowed-p.
+
         * markers.texi (Moving Markers): Add xref to Point (Bug#7151).
 
         * syntax.texi (Low-Level Parsing): Add xref to Parser State
diff --git a/doc/lispref/positions.texi b/doc/lispref/positions.texi
index a0c65319850..c4576e6456d 100644
--- a/doc/lispref/positions.texi
+++ b/doc/lispref/positions.texi
@@ -874,18 +874,18 @@ commands to a limited range of characters in a buffer.  The text that
 remains addressable is called the @dfn{accessible portion} of the
 buffer.
 
-  Narrowing is specified with two buffer positions which become the
-beginning and end of the accessible portion.  For most editing commands
-and most Emacs primitives, these positions replace the values of the
-beginning and end of the buffer.  While narrowing is in effect, no text
-outside the accessible portion is displayed, and point cannot move
-outside the accessible portion.
-
-  Values such as positions or line numbers, which usually count from the
-beginning of the buffer, do so despite narrowing, but the functions
-which use them refuse to operate on text that is inaccessible.
-
-  The commands for saving buffers are unaffected by narrowing; they save
+  Narrowing is specified with two buffer positions, which become the
+beginning and end of the accessible portion.  For most editing
+commands and primitives, these positions replace the values of the
+beginning and end of the buffer.  While narrowing is in effect, no
+text outside the accessible portion is displayed, and point cannot
+move outside the accessible portion.  Note that narrowing does not
+alter actual buffer positions (@pxref{Point}); it only determines
+which positions are considered the accessible portion of the buffer.
+Most functions refuse to operate on text that is outside the
+accessible portion.
+
+  Commands for saving buffers are unaffected by narrowing; they save
 the entire buffer regardless of any narrowing.
 
   If you need to display in a single buffer several very different
@@ -924,6 +924,11 @@ It is equivalent to the following expression:
 @end example
 @end deffn
 
+@defun buffer-narrowed-p
+This function returns non-@code{nil} if the buffer is narrowed, and
+@code{nil} otherwise.
+@end defun
+
 @defspec save-restriction body@dots{}
 This special form saves the current bounds of the accessible portion,
 evaluates the @var{body} forms, and finally restores the saved bounds,
diff --git a/etc/NEWS b/etc/NEWS
index bc1c49fe946..b85d64f83a3 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -645,6 +645,9 @@ The interpretation of the DECLS is determined by `defun-declarations-alist'.
 
 ** New error type and new function `user-error'.  Doesn't trigger the debugger.
 
++++
+** New utility function `buffer-narrowed-p'.
+
 ** Window changes
 
 *** The functions get-lru-window, get-mru-window and get-largest-window
diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 33e641b5fc1..7aae8fd7854 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,6 +1,13 @@
 2012-09-07  Chong Yidong  <cyd@gnu.org>
 
-        * simple.el (count-words--buffer-message): Fix narrowing check.
+        * subr.el (buffer-narrowed-p): New function.
+
+        * ses.el (ses-widen):
+        * simple.el (count-words--buffer-message):
+        * net/browse-url.el (browse-url-of-buffer): Use it
+
+        * simple.el (count-words-region): Don't signal an error if there
+        is a non-nil prefix arg and the mark is not set.
 
         * help.el (describe-key-briefly): Allow the message to be seen
         when invoked from the minibuffer (Bug#7014).
diff --git a/lisp/emacs-lisp/cl-loaddefs.el b/lisp/emacs-lisp/cl-loaddefs.el
index 7d70d22c9cd..a59beaeb7ac 100644
--- a/lisp/emacs-lisp/cl-loaddefs.el
+++ b/lisp/emacs-lisp/cl-loaddefs.el
@@ -260,7 +260,7 @@ Remove from SYMBOL's plist the property PROPNAME and its value.
 ;;;;;;  cl-typecase cl-ecase cl-case cl-load-time-value cl-eval-when
 ;;;;;;  cl-destructuring-bind cl-function cl-defmacro cl-defun cl-gentemp
 ;;;;;;  cl-gensym cl--compiler-macro-cXXr cl--compiler-macro-list*)
-;;;;;;  "cl-macs" "cl-macs.el" "e09b4be5072a8b52d40af6e073876e76")
+;;;;;;  "cl-macs" "cl-macs.el" "9f9bae5b8ccaf325bd59ba9be2b27c44")
 ;;; Generated autoloads from cl-macs.el
 
 (autoload 'cl--compiler-macro-list* "cl-macs" "\
diff --git a/lisp/net/browse-url.el b/lisp/net/browse-url.el
index 20d71215926..d1d33bfe566 100644
--- a/lisp/net/browse-url.el
+++ b/lisp/net/browse-url.el
@@ -743,7 +743,7 @@ narrowed."
     (and buffer (set-buffer buffer))
     (let ((file-name
            ;; Ignore real name if restricted
-           (and (= (- (point-max) (point-min)) (buffer-size))
+           (and (not (buffer-narrowed-p))
                 (or buffer-file-name
                     (and (boundp 'dired-directory) dired-directory)))))
       (or file-name
diff --git a/lisp/ses.el b/lisp/ses.el
index 8add16a6996..7cdac74e310 100644
--- a/lisp/ses.el
+++ b/lisp/ses.el
@@ -1270,11 +1270,9 @@ when the width of cell (ROW,COL) has changed."
 ;; The data area
 ;;----------------------------------------------------------------------------
 
-(defun ses-narrowed-p () (/= (- (point-max) (point-min)) (buffer-size)))
-
 (defun ses-widen ()
   "Turn off narrowing, to be reenabled at end of command loop."
-  (if (ses-narrowed-p)
+  (if (buffer-narrowed-p)
       (setq ses--deferred-narrow t))
   (widen))
 
diff --git a/lisp/simple.el b/lisp/simple.el
index ca73ba1b03a..d87ae3c5c15 100644
--- a/lisp/simple.el
+++ b/lisp/simple.el
@@ -974,7 +974,9 @@ rather than the region.
 
 If called from Lisp, return the number of words between positions
 START and END."
-  (interactive "r\nP")
+  (interactive (if current-prefix-arg
+                   (list nil nil current-prefix-arg)
+                 (list (region-beginning) (region-end) nil)))
   (cond ((not (called-interactively-p 'any))
          (count-words start end))
         (arg
@@ -1008,9 +1010,7 @@ END, without printing any message."
 
 (defun count-words--buffer-message ()
   (count-words--message
-   (if (= (- (point-max) (point-min)) (buffer-size))
-       "Buffer"
-     "Narrowed part of buffer")
+   (if (buffer-narrowed-p) "Narrowed part of buffer" "Buffer")
    (point-min) (point-max)))
 
 (defun count-words--message (str start end)
diff --git a/lisp/subr.el b/lisp/subr.el
index 74afd59f8d5..621622e70eb 100644
--- a/lisp/subr.el
+++ b/lisp/subr.el
@@ -2647,6 +2647,10 @@ directory if it does not exist."
 
 ;;;; Misc. useful functions.
 
+(defsubst buffer-narrowed-p ()
+  "Return non-nil if the current buffer is narrowed."
+  (/= (- (point-max) (point-min)) (buffer-size)))
+
 (defun find-tag-default ()
   "Determine default tag to search for, based on text at point.
 If there is no plausible default, return nil."