hg diff -p
diff -r c158c001bfd3 test.php
--- a/test.php  Mon Dec 24 11:48:27 2007 +0100
+++ b/test.php  Mon Dec 24 11:50:20 2007 +0100
@@ -1,4 +1,5 @@
 <?php

 function foo() {
+  echo 'test';
 }