SF Bug #1454485, array.array('u') could crash the interpreter when
passing a string.  Martin already fixed the actual crash by ensuring
Py_UNICODE is unsigned.  As discussed on python-dev, this fix
removes the possibility of creating a unicode string from a raw buffer.

There is an outstanding question of how to fix the crash in 2.4.
diff --git a/Python/getargs.c b/Python/getargs.c
index e6f607a..5908e6b 100644
--- a/Python/getargs.c
+++ b/Python/getargs.c
@@ -1042,11 +1042,8 @@
 				STORE_SIZE(PyUnicode_GET_SIZE(arg));
 			}
 			else {
-			char *buf;
-			Py_ssize_t count = convertbuffer(arg, p, &buf);
-			if (count < 0)
-				return converterr(buf, arg, msgbuf, bufsize);
-			STORE_SIZE(count/(sizeof(Py_UNICODE))); 
+				return converterr("cannot convert raw buffers",
+						  arg, msgbuf, bufsize);
 			}
 			format++;
 		} else {