I made a mistake in msg155410. The results in the message are WITHOUT "unicodeerror.diff" applied. When it is applied, the IDLE shell gives:


>>> '\U00010330'
Traceback (most recent call last):
  File "<pyshell#1>", line 1, in <module>
    '\U00010330'
UnicodeEncodeError: 'UCS-2' codec can't encode characters in position 1-1: Non-BMP character not supported in Tk
Traceback (most recent call last):
** IDLE Internal Exception: 
  File "idlelib/run.py", line 98, in main
    ret = method(*args, **kwargs)
  File "idlelib/run.py", line 305, in runcode
    print_exception()
  File "idlelib/run.py", line 168, in print_exception
    print(line, end='', file=efile)
  File "idlelib/rpc.py", line 599, in __call__
    value = self.sockio.remotecall(self.oid, self.name, args, kwargs)
  File "idlelib/rpc.py", line 214, in remotecall
    return self.asyncreturn(seq)
  File "idlelib/rpc.py", line 245, in asyncreturn
    return self.decoderesponse(response)
  File "idlelib/rpc.py", line 265, in decoderesponse
    raise what
ValueError: max() arg is an empty sequence

I will need to rework the rpc_marshal_exception patch.