Queue cleanup

[Lawrence D'Oliveiro]

In message <7xvd6sv0n4.fsf at ruckus.brouhaha.com>, Paul Rubin wrote:

> Lawrence D'Oliveiro <ldo at geek-central.gen.new_zealand> writes:
>>>          AddrObj = PyTuple_GetItem(TheBufferInfo, 0);
>>>          LenObj = PyTuple_GetItem(TheBufferInfo, 1);
>>> 
>>> the first PyTuple_GetItem succeeds and the second one fails.
>>
>> Admittedly, I did take a shortcut here: array.buffer_info returns a tuple
>> of two items, so I’m not expecting one GetItem to succeed and the other
>> to fail.
> 
> FromArray is a parameter to the function, with no type check to make
> sure it's really an array.  In fact your code allows for the possibility
> that it doesn't support the buffer_info operation (if I understand the
> purpose of the null return check after the PyObject_CallMethod) which
> means it's prepared for the argument to -not- be an array.

That reinforces my point, about how easy it was to check the correctness of 
the code. In this case one simple fix, like this

diff --git a/spuhelper.c b/spuhelper.c
index 83fd4eb..2ba8197 100644
--- a/spuhelper.c
+++ b/spuhelper.c
@@ -151,10 +151,12 @@ static void GetBufferInfo
        if (TheBufferInfo == 0)
            break;
        AddrObj = PyTuple_GetItem(TheBufferInfo, 0);
-       LenObj = PyTuple_GetItem(TheBufferInfo, 1);
        if (PyErr_Occurred())
            break;
        Py_INCREF(AddrObj);
+       LenObj = PyTuple_GetItem(TheBufferInfo, 1);
+       if (PyErr_Occurred())
+           break;
        Py_INCREF(LenObj);
        *addr = PyInt_AsUnsignedLongMask(AddrObj);
        *len = PyInt_AsUnsignedLongMask(LenObj);

would render the code watertight. See how easy it is?