New function diff-show-trailing-blanks in diff-mode.el.

etc/ChangeLog

+2008-07-24  Vinicius Jose Latorre  <viniciusjl@ig.com.br>
+
+	* NEWS: New function `diff-show-trailing-blanks' in diff-mode.el.
+
 2008-07-24  Michael Albinus  <michael.albinus@gmx.de>
 
 	* NEWS: Add xesam.el.

etc/NEWS

@@ -516,6 +516,9 @@ which have installed this software.
 
 * Changes in Specialized Modes and Packages in Emacs 23.1
 
+** Diff mode
+*** New function `diff-show-trailing-blanks'.
+
 ** Abbrev has been rewritten in Elisp and extended with more flexibility.
 *** New functions: abbrev-get, abbrev-put, abbrev-table-get, abbrev-table-put,
     abbrev-table-p, abbrev-insert, abbrev-table-menu.

lisp/ChangeLog

+2008-07-24  Vinicius Jose Latorre  <viniciusjl@ig.com.br>
+
+	* diff-mode.el (diff-show-trailing-blanks): New fun.  Show trailing
+	blanks in modified lines for diff-mode.
+
 2008-07-24  Michael Albinus  <michael.albinus@gmx.de>
 
 	* Makefile.in (ELCFILES): Add net/xesam.el.

lisp/diff-mode.el

@@ -1881,6 +1881,13 @@ I.e. like `add-change-log-entry-other-window' but applied to all hunks."
         ;; When there's no more hunks, diff-hunk-next signals an error.
 	(error nil)))))
 
+(defun diff-show-trailing-blanks ()
+  "Show trailing blanks in modified lines for diff-mode."
+  (interactive)
+  (let ((whitespace-style '(trailing))
+        (whitespace-trailing-regexp "^[-\+!<>].*?\\([\t ]+\\)$"))
+    (whitespace-mode 1)))     ; display trailing blanks in diff buffer
+
 ;; provide the package
 (provide 'diff-mode)