wxInputStream and the tell() file method

wxPython Dev
1

Hi,

When wxpython-2.4.2.4 is compiled with largefiles support, wxInputStream
wrapping file-alike methods will fail to wrap the tell() file method if
it doesn't return a long object, such as in the case of the cStringIO's.

Attached is an example of this bug.

The wrapper code from wxPython/src/helpers.cpp is very strange:

off_t wxPyCBInputStream::OnSysTell() const {
    wxPyBeginBlockThreads();
    PyObject* arglist = Py_BuildValue("()");
    PyObject* result = PyEval_CallObject(m_tell, arglist);
    Py_DECREF(arglist);
    off_t o = 0;
    if (result != NULL) {
#ifdef _LARGE_FILES
        if (PyLong_Check(result))
            o = PyLong_AsLongLong(result);
        else
#else

Isn't this "#else" directive in excess here? Otherwise 'result'
reference count is not decreased when 'PyLong_Check(result)' verifies,
and result isn't used otherwise...

        o = PyInt_AsLong(result);
#endif
        Py_DECREF(result);
    };
    wxPyEndBlockThreads();
    return o;
}

Sorry for not testing this out but I'm using wxPython from Debian and it
would be too much trouble to compile it from scratch.

Regards,

José Fonseca

test.py (1.46 KB)

2

José Fonseca wrote:

Hi,

When wxpython-2.4.2.4 is compiled with largefiles support, wxInputStream
wrapping file-alike methods will fail to wrap the tell() file method if
it doesn't return a long object, such as in the case of the cStringIO's.

Attached is an example of this bug.

The wrapper code from wxPython/src/helpers.cpp is very strange:

off_t wxPyCBInputStream::OnSysTell() const {
   wxPyBeginBlockThreads();
   PyObject* arglist = Py_BuildValue("()");
   PyObject* result = PyEval_CallObject(m_tell, arglist);
   Py_DECREF(arglist);
   off_t o = 0;
   if (result != NULL) {
#ifdef _LARGE_FILES
       if (PyLong_Check(result))
           o = PyLong_AsLongLong(result);
       else
#else

Isn't this "#else" directive in excess here?

Yes. You are correct. It should be changed to #endif.

···

--
Robin Dunn
Software Craftsman
http://wxPython.org Java give you jitters? Relax with wxPython!