Error happens when callee raise an empty Exception

[tangyouze]

If callee raise Exception() or an raise ApplicationError('com.crossbardemo') without args, there would be an error in protocol.py during handle the error.

The error may come with line 850 in protocol.py

                            errmsg = "{0}".format(err.value.args[0])

as err.value.args is an empty list

Here's the code

try:
    import asyncio
except ImportError:
    # Trollius >= 0.3 was renamed
    import trollius as asyncio

from autobahn import wamp
from autobahn.wamp.exception import ApplicationError
from autobahn.asyncio.wamp import ApplicationSession, ApplicationRunner

class Component(ApplicationSession):
    """
    Example WAMP application backend that raised exceptions.
    """

    @asyncio.coroutine
    def onJoin(self, details):

        def sqrt():
            # raise empty exception
            raise Exception()

        yield from self.register(sqrt, u'com.myapp.sqrt')

        try:
            yield from self.call('com.myapp.sqrt')
        except:
            print('exception catch')

if __name__ == '__main__':
    runner = ApplicationRunner(
        u"ws://f1:8080/ws",
        u"crossbardemo",
        debug_wamp=False,  # optional; log many WAMP details
        debug=False,  # optional; log even more details
    )
    runner.run(Component)

and will come up with

C:\Anaconda3\python.exe D:/Dropbox/code/quantlib/learn/error_exception.py
Exception in callback add_callbacks.<locals>.done(<Future finis...n=Exception()>) at C:\Anaconda3\lib\site-packages\txaio\aio.py:336
handle: <Handle add_callbacks.<locals>.done(<Future finis...n=Exception()>) at C:\Anaconda3\lib\site-packages\txaio\aio.py:336>
Traceback (most recent call last):
  File "C:\Anaconda3\lib\site-packages\txaio\aio.py", line 338, in done
    res = f.result()
  File "C:\Anaconda3\lib\asyncio\futures.py", line 275, in result
    raise self._exception
  File "C:\Anaconda3\lib\site-packages\txaio\aio.py", line 278, in as_future
    res = fun(*args, **kwargs)
  File "D:/Dropbox/code/quantlib/learn/error_exception.py", line 24, in sqrt
    raise Exception()
Exception

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\Anaconda3\lib\asyncio\events.py", line 120, in _run
    self._callback(*self._args)
  File "C:\Anaconda3\lib\site-packages\txaio\aio.py", line 345, in done
    errback(create_failure())
  File "C:\Anaconda3\lib\site-packages\autobahn\wamp\protocol.py", line 805, in error
    errmsg = "{0}".format(err.value.args[0])
IndexError: tuple index out of range

Process finished with exit code -1

[jvdm]

Duplicate of issue #484?

[tangyouze]

Yes, Sorry I missed that issue.

[oberstet]

duplicate of #484