I'm writing a C extension module and discovered that Py_CLEAR() causes acrash if the programmer happened to name their variable "tmp".  ThePy_CLEAR() macro internally uses the name "tmp" in a new scope, hidingthe callers "tmp", and calling Py_DECREF() on an essentially random bitof memory.I suggest changing Py_CLEAR() to use something a little less common than"tmp".  Perhaps "_py_tmp".For easy reference, here's how Py_CLEAR() is defined now:#define Py_CLEAR(op)\        do {                            \                if (op) {\                        PyObject *tmp = (PyObject *)(op);\                        (op) = NULL;\                        Py_DECREF(tmp);\                }\        } while (0)

A better option may be to append _tmp to the passed in token:#define Py_CLEAR(op)\        do {                            \                if (op) {\                        PyObject *op##_tmp = (PyObject *)(op);\                        (op) = NULL;\                        Py_DECREF(op##_tmp);\                }\        } while (0)

Appending _tmp is a good idea, but it won't work when the parameterisn't a simple symbol.  For example, there's a line in cPickle.c likethis: Py_CLEAR(*p).

Committed the fixr64927. Thanks.