diff -r f8e435d6a801 Python/pythonrun.c
--- a/Python/pythonrun.c	Sun Aug 05 00:33:10 2012 +0200
+++ b/Python/pythonrun.c	Sun Aug 05 09:58:53 2012 +0900
@@ -974,8 +974,12 @@
 #ifdef MS_WINDOWS
     /* sys.stdin: enable universal newline mode, translate "\r\n" and "\r"
        newlines to "\n".
-       sys.stdout and sys.stderr: translate "\n" to "\r\n". */
-    newline = NULL;
+       sys.stdout and sys.stderr: translate "\n" to "\r\n" if 
+       PYTHONUNBUFFERED not set. */
+    if (!Py_UnbufferedStdioFlag)
+        newline = NULL;
+    else
+        newline = "";
 #else
     /* sys.stdin: split lines at "\n".
        sys.stdout and sys.stderr: don't translate newlines (use "\n"). */