* lisp/simple.el (delete-trailing-whitespace): New optional buffer

bound parameters.

2 files changed, 24 insertions, 11 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 043c8bebea6..68fdfbf4d2e 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,8 @@
+2011-02-11  Deniz Dogan  <deniz.a.m.dogan@gmail.com>
+
+        * simple.el (delete-trailing-whitespace): New optional buffer
+        bound parameters.
+
 2011-02-11  Bastien Guerry  <bzg@altern.org>
 
         * files.el (basic-save-buffer): save unmodified buffers when
diff --git a/lisp/simple.el b/lisp/simple.el
index 537c9a80838..f19525aba4c 100644
--- a/lisp/simple.el
+++ b/lisp/simple.el
@@ -614,22 +614,30 @@ On nonblank line, delete any immediately following blank lines."
     (if (looking-at "^[ \t]*\n\\'")
         (delete-region (point) (point-max)))))
 
-(defun delete-trailing-whitespace ()
+(defun delete-trailing-whitespace (&optional start end)
   "Delete all the trailing whitespace across the current buffer.
 All whitespace after the last non-whitespace character in a line is deleted.
 This respects narrowing, created by \\[narrow-to-region] and friends.
-A formfeed is not considered whitespace by this function."
-  (interactive "*")
+A formfeed is not considered whitespace by this function.
+If the region is active, only delete whitespace within the region."
+  (interactive (progn
+                 (barf-if-buffer-read-only)
+                 (if (use-region-p)
+                     (list (region-beginning) (region-end))
+                   (list nil nil))))
   (save-match-data
     (save-excursion
-      (goto-char (point-min))
-      (while (re-search-forward "\\s-$" nil t)
-        (skip-syntax-backward "-" (save-excursion (forward-line 0) (point)))
-        ;; Don't delete formfeeds, even if they are considered whitespace.
-        (save-match-data
-          (if (looking-at ".*\f")
-              (goto-char (match-end 0))))
-        (delete-region (point) (match-end 0))))))
+      (let ((end-marker (copy-marker (or end (point-max))))
+            (start (or start (point-min))))
+        (goto-char start)
+        (while (re-search-forward "\\s-$" end-marker t)
+          (skip-syntax-backward "-" (save-excursion (forward-line 0) (point)))
+          ;; Don't delete formfeeds, even if they are considered whitespace.
+          (save-match-data
+            (if (looking-at ".*\f")
+                (goto-char (match-end 0))))
+          (delete-region (point) (match-end 0)))
+        (set-marker end-marker nil)))))
 
 (defun newline-and-indent ()
   "Insert a newline, then indent according to major mode.