pass along the context to extension functions, this was already being done in all cases except for the render engine.

this allows python to NULL its internal context while scripts are not running.

source/blender/python/intern/bpy_operator.c

@@ -52,8 +52,13 @@ static PyObject *pyop_poll(PyObject *UNUSED(self), PyObject *args)
 	int context= WM_OP_EXEC_DEFAULT;
 
 	// XXX Todo, work out a better solution for passing on context, could make a tuple from self and pack the name and Context into it...
-	bContext *C = BPy_GetContext();
+	bContext *C= (bContext *)BPy_GetContext();
 	
+	if(C==NULL) {
+		PyErr_SetString(PyExc_SystemError, "Context is None, cant poll any operators");
+		return NULL;
+	}
+
 	if (!PyArg_ParseTuple(args, "s|Os:_bpy.ops.poll", &opname, &context_dict, &context_str))
 		return NULL;
 	
@@ -114,7 +119,12 @@ static PyObject *pyop_call(PyObject *UNUSED(self), PyObject *args)
 	int context= WM_OP_EXEC_DEFAULT;
 
 	// XXX Todo, work out a better solution for passing on context, could make a tuple from self and pack the name and Context into it...
-	bContext *C = BPy_GetContext();
+	bContext *C = (bContext *)BPy_GetContext();
+	
+	if(C==NULL) {
+		PyErr_SetString(PyExc_SystemError, "Context is None, cant poll any operators");
+		return NULL;
+	}
 	
 	if (!PyArg_ParseTuple(args, "sO|O!s:_bpy.ops.call", &opname, &context_dict, &PyDict_Type, &kw, &context_str))
 		return NULL;
@@ -232,8 +242,13 @@ static PyObject *pyop_as_string(PyObject *UNUSED(self), PyObject *args)
 	char *buf = NULL;
 	PyObject *pybuf;
 
-	bContext *C = BPy_GetContext();
+	bContext *C = (bContext *)BPy_GetContext();
 
+	if(C==NULL) {
+		PyErr_SetString(PyExc_SystemError, "Context is None, cant get the string representation of this object.");
+		return NULL;
+	}
+	
 	if (!PyArg_ParseTuple(args, "s|O!i:_bpy.ops.as_string", &opname, &PyDict_Type, &kw, &all_args))
 		return NULL;