[python-sybase] Connection unusable after an exception has been raised

[Skip Montanaro]

Perhaps I spoke a bit too soon...

    Dave> There are two possible ways to attempt a fix.

    Dave> 1) Construct the Fetcher in the FETCHING state.  This will mean
    Dave>    that any exception raised in the ct_command() or the ct_send()
    Dave>    function will result in ct_cancel(CS_CANCEL_ALL) when the
    Dave>    Fetcher is deleted.

    Dave>      In _FetchLazy.__init__() change:
    Dave>          self._state = _LAZY_IDLE
    Dave>      to
    Dave>          self._state = _LAZY_FETCHING

    Skip> This didn't work.

    Dave> 2) Set the Fetcher state to FETCHING immediately before calling
    Dave>    ct_send() in _FetchLazy.start().

    Dave>      In _FetchLazy.start() change:
    Dave>          status = self._cmd.ct_send()
    Dave>      to
    Dave>          self._set_state(_LAZY_FETCHING)
    Dave>          status = self._cmd.ct_send()

    Skip> This did...

Solution #2 worked on Solaris/Intel, but not on Linux (neither did solution
#1).  Cursors created after an error still give a ct_send() error with this
message when their execute() method is called:

    ct_send(): user api layer: external error: This routine cannot be called
    because another command structure has results pending.

Skip