C API PyErr_Clear vs PyObject_HasAttrString

[Robin Becker]

I'm trying to understand why this code causes a seg fault second time 
through; the code is part of a setattr and is testing if the value is an 
integer or has red, green and blue attributes. This code later goes on 
to raise a ValueError if  that's not the case.

if((i = PyArg_Parse(value,"i",&cv))){
	c->value = cv;
	c->valid = 1;
	return 1;
	}

rgb = PyObject_HasAttrString(value,"red")
	&& PyObject_HasAttrString(value,"green")
	&& PyObject_HasAttrString(value,"blue");
PyErr_Clear();


.......
PyErr_SetString(PyExc_ValueError, "bad color value");


Both calls should fail and raise ValueError, but the second call causes 
a seg fault in Python 2.3.4 (not in 2.2 and earlier).

In 2.3.4 I found that moving the PyErr_Clear() before the calculation of 
rgb fixes the problem.

I assume the problem is that something in the rgb calculation is failing 
because the python error flag is set. Is that a bug in the 
implementation of PyObject_HasAttrString or is it my fault for not 
knowing which API calls need a cleared error flag?
-- 
Robin Becker