python - 使用 MSN 协议(protocol)运行 twins.words 示例时出现异常

Question

我正在运行位于此处的 Twisted 文档中的 twinsed.words MSN 协议(protocol)示例:http://twistedmatrix.com/projects/words/documentation/examples/msn_example.py

但是，当我运行此示例脚本时，我收到 UnhandledError 异常:

2012-05-12 15:39:51-0300 [-] Log opened.
2012-05-12 15:39:51-0300 [-] Starting factory <twisted.internet.protocol.ClientFactory instance at  0x8c6c18c>
2012-05-12 15:39:52-0300 [Dispatch,client] Starting factory <twisted.words.protocols.msn.NotificationFactory instance at 0x8c6c2cc>
2012-05-12 15:39:52-0300 [Dispatch,client] Stopping factory <twisted.internet.protocol.ClientFactory instance at 0x8c6c18c>
2012-05-12 15:39:53-0300 [Notification,client] Starting factory <twisted.internet.protocol.ClientFactory instance at 0x8c710ec>
2012-05-12 15:39:53-0300 [Notification,client] Unhandled Error
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/twisted/python/log.py", line 84, in callWithLogger
    return callWithContext({"system": lp}, func, *args, **kw)
  File "/usr/lib/python2.7/dist-packages/twisted/python/log.py", line 69, in callWithContext
    return context.call({ILogContext: newCtx}, func, *args, **kw)
  File "/usr/lib/python2.7/dist-packages/twisted/python/context.py", line 118, in callWithContext
    return self.currentContext().callWithContext(ctx, func, *args, **kw)
  File "/usr/lib/python2.7/dist-packages/twisted/python/context.py", line 81, in callWithContext
    return func(*args,**kw)
--- <exception caught here> ---
  File "/usr/lib/python2.7/dist-packages/twisted/internet/selectreactor.py", line 146, in _doReadOrWrite
    why = getattr(selectable, method)()
  File "/usr/lib/python2.7/dist-packages/twisted/internet/tcp.py", line 460, in doRead
    rval = self.protocol.dataReceived(data)
  File "/usr/lib/python2.7/dist-packages/twisted/protocols/basic.py", line 564, in dataReceived
    why = self.lineReceived(line)
  File "/usr/lib/python2.7/dist-packages/twisted/words/protocols/msn.py", line 670, in lineReceived
    handler(params.split())
  File "/usr/lib/python2.7/dist-packages/twisted/words/protocols/msn.py", line 848, in handle_USR
    authData=params[3])
  File "/usr/lib/python2.7/dist-packages/twisted/internet/defer.py", line 108, in execute
    return succeed(result)
  File "/usr/lib/python2.7/dist-packages/twisted/internet/defer.py", line 71, in succeed
    d.callback(result)
  File "/usr/lib/python2.7/dist-packages/twisted/internet/defer.py", line 360, in callback
    assert not isinstance(result, Deferred)
exceptions.AssertionError: 

2012-05-12 15:39:53-0300 [Notification,client] Stopping factory <twisted.words.protocols.msn.NotificationFactory instance at 0x8c6c2cc>
2012-05-12 15:39:55-0300 [PassportNexus,client] Starting factory <twisted.internet.protocol.ClientFactory instance at 0x8d014cc>
2012-05-12 15:39:55-0300 [PassportNexus,client] Stopping factory <twisted.internet.protocol.ClientFactory instance at 0x8c710ec>
2012-05-12 15:39:56-0300 [PassportLogin,client] Stopping factory <twisted.internet.protocol.ClientFactory instance at 0x8d014cc>

• Python 2.7.2+
• 扭曲11.0.0
• pyOpenSSL 0.12

Answer 1

我以前从未使用过 t.w.protocols.msn 协议(protocol)，但在我看来，line 846 上的 Twisted 的 msn.py 中存在错误。 。这是有问题的函数:

def handle_USR(self, params):
    if len(params) != 4 and len(params) != 6:
        raise MSNProtocolError, "Invalid Number of Parameters for USR"

    mechanism = params[1]
    if mechanism == "OK":
        self.loggedIn(params[2], unquote(params[3]), int(params[4]))
    elif params[2].upper() == "S":
        # we need to obtain auth from a passport server
        f = self.factory
        d = execute(                                                   # <------- here
            _login, f.userHandle, f.password, f.passportServer,
            authData=params[3])
        d.addCallback(self._passportLogin)
        d.addErrback(self._passportError)

defer.execute 使用 msn._login 及其参数调用，但 msn._login 应该返回 Deferred。将 defer.execute 与可能返回 Deferred 的函数一起使用是不合适的，因为它会立即通过 defer.succeed 包装在另一个 Deferred 中，并且 Deferred 不能保存其他延期结果。

那里的execute调用应该使用defer.maybeDeferred来代替。我希望如果您将 maybeDeferred 添加到文件顶部的 twisted.internet.defer 的导入中，并将此 execute 调用更改为一个 maybeDeferred 调用，它将开始工作(或者至少由于不同的错误而开始失败:​​))。