gnu: Add GNU Wdiff.

* gnu/packages/wdiff.scm: New file.
* Makefile.am (MODULES): Add it.

Makefile.am

@@ -152,6 +152,7 @@ MODULES =					\
   gnu/packages/time.scm				\
   gnu/packages/tmux.scm 			\
   gnu/packages/tor.scm				\
+  gnu/packages/wdiff.scm			\
   gnu/packages/wget.scm				\
   gnu/packages/which.scm			\
   gnu/packages/xml.scm				\

gnu/packages/wdiff.scm

@@ -0,0 +1,61 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2013 Nikita Karetnikov <nikita@karetnikov.org>
+;;;
+;;; This file is part of GNU Guix.
+;;;
+;;; GNU Guix is free software; you can redistribute it and/or modify it
+;;; under the terms of the GNU General Public License as published by
+;;; the Free Software Foundation; either version 3 of the License, or (at
+;;; your option) any later version.
+;;;
+;;; GNU Guix is distributed in the hope that it will be useful, but
+;;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;;; GNU General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU General Public License
+;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
+
+(define-module (gnu packages wdiff)
+  #:use-module (guix licenses)
+  #:use-module (guix packages)
+  #:use-module (guix download)
+  #:use-module (guix build-system gnu)
+  #:use-module (gnu packages screen)
+  #:use-module (gnu packages which))
+
+(define-public wdiff
+  (package
+    (name "wdiff")
+    (version "1.1.2")
+    (source
+     (origin
+      (method url-fetch)
+      (uri (string-append "mirror://gnu/wdiff/wdiff-"
+                          version ".tar.gz"))
+      (sha256
+       (base32
+        "0q78y5awvjjmsvizqilbpwany62shlmlq2ayxkjbygmdafpk1k8j"))))
+    (build-system gnu-build-system)
+    (arguments
+     `(#:phases (alist-cons-before
+                 'check 'fix-sh
+                 (lambda _
+                   (substitute* "tests/testsuite"
+                     (("#! /bin/sh")
+                      (string-append "#!" (which "sh")))))
+                 %standard-phases)))
+    (inputs `(("screen" ,screen)
+              ("which" ,which)))
+    (home-page "https://www.gnu.org/software/wdiff/")
+    (synopsis
+     "GNU Wdiff, a tool for comparing files on a word by word basis")
+    (description
+     "GNU Wdiff is a front end to 'diff' for comparing files on a word per
+word basis.  A word is anything between whitespace.  This is useful for
+comparing two texts in which a few words have been changed and for which
+paragraphs have been refilled.  It works by creating two temporary files, one
+word per line, and then executes 'diff' on these files.  It collects the
+'diff' output and uses it to produce a nicer display of word differences
+between the original files.")
+    (license gpl3+)))