Issue #10912: Clarify the documentation of PyObject_RichCompareBool. Thanks to…

Issue #10912: Clarify the documentation of PyObject_RichCompareBool. Thanks to Devin Jeanpierre for spotting the problem.

Doc/c-api/object.rst

@@ -108,6 +108,9 @@ Object Protocol
    Python expression ``o1 op o2``, where ``op`` is the operator corresponding to
    *opid*.
 
+.. note::
+   If *o1* and *o2* are the same object, :c:func:`PyObject_RichCompareBool`
+   will always return ``1`` for :const:`Py_EQ` and ``0`` for :const:`Py_NE`.
 
 .. c:function:: PyObject* PyObject_Repr(PyObject *o)