Index: Objects/stringobject.c
===================================================================
--- Objects/stringobject.c	(revision 58376)
+++ Objects/stringobject.c	(working copy)
@@ -772,7 +772,7 @@
 	Py_ssize_t length = PyString_GET_SIZE(op);
 	size_t newsize = 3 + 4 * Py_Size(op);
 	PyObject *v;
-	if (newsize > PY_SSIZE_T_MAX || newsize / 4 != Py_Size(op)) {
+	if (newsize > PY_SSIZE_T_MAX || (newsize-3) / 4 != Py_Size(op)) {
 		PyErr_SetString(PyExc_OverflowError,
 			"string is too large to make repr");
 	}
@@ -803,7 +803,7 @@
 			;
 		}
 
-		*p++ = 's', *p++ = quote;
+		*p++ = 'b', *p++ = quote;
 		for (i = 0; i < Py_Size(op); i++) {
 			/* There's at least enough room for a hex escape
 			   and a closing quote. */
@@ -875,7 +875,7 @@
                 if (PyBytes_Check(bb))
 			return PyBytes_Concat((PyObject *)a, bb);
 		PyErr_Format(PyExc_TypeError,
-			     "cannot concatenate 'str8' and '%.200s' objects",
+			     "cannot concatenate 'bytes' and '%.200s' objects",
 			     Py_Type(bb)->tp_name);
 		return NULL;
 	}
@@ -3091,7 +3091,7 @@
         goto onError;
     if (!PyBytes_Check(v)) {
         PyErr_Format(PyExc_TypeError,
-                     "[str8] encoder did not return a bytes object "
+                     "[bytes] encoder did not return a bytes object "
                      "(type=%.400s)",
                      Py_Type(v)->tp_name);
         Py_DECREF(v);
@@ -3754,7 +3754,7 @@
 
 	if (type != &PyString_Type)
 		return str_subtype_new(type, args, kwds);
-	if (!PyArg_ParseTupleAndKeywords(args, kwds, "|O:str8", kwlist, &x))
+	if (!PyArg_ParseTupleAndKeywords(args, kwds, "|O:bytes", kwlist, &x))
 		return NULL;
 	if (x == NULL)
 		return PyString_FromString("");