Add functions PyUnicode_Append() and PyUnicode_AppendAndDel() that mirror PyString_Concat() and PyString_ConcatAndDel() (the name PyUnicode_Concat() was already taken). Change PyObject_Repr() to always return a unicode object. Update all repr implementations to return unicode objects. Add a function PyObject_ReprStr8() that calls PyObject_Repr() and converts the result to an 8bit string. Use PyObject_ReprStr8() where using PyObject_Repr() can't be done straightforward.

--- a/Python/errors.c	Fri May 18 17:04:42 2007 +0000
+++ b/Python/errors.c	Fri May 18 17:15:44 2007 +0000
@@ -54,7 +54,7 @@
 {
 	if (exception != NULL &&
 	    !PyExceptionClass_Check(exception)) {
-		PyObject *excstr = PyObject_Repr(exception);
+		PyObject *excstr = PyObject_ReprStr8(exception);
 		PyErr_Format(PyExc_SystemError,
 			     "exception %s not a BaseException subclass",
 			     PyString_AS_STRING(excstr));