improve abstract property support (closes #11610)

Thanks to Darren Dale for patch.

1 files changed, 38 insertions, 1 deletions

diff --git a/Objects/descrobject.c b/Objects/descrobject.c
index 32b1593..1268df9 100644
--- a/Objects/descrobject.c
+++ b/Objects/descrobject.c
@@ -1380,6 +1380,43 @@ property_init(PyObject *self, PyObject *args, PyObject *kwds)
     return 0;
 }
 
+static PyObject *
+property_get___isabstractmethod__(propertyobject *prop, void *closure)
+{
+    int res = _PyObject_IsAbstract(prop->prop_get);
+    if (res == -1) {
+        return NULL;
+    }
+    else if (res) {
+        Py_RETURN_TRUE;
+    }
+
+    res = _PyObject_IsAbstract(prop->prop_set);
+    if (res == -1) {
+        return NULL;
+    }
+    else if (res) {
+        Py_RETURN_TRUE;
+    }
+
+    res = _PyObject_IsAbstract(prop->prop_del);
+    if (res == -1) {
+        return NULL;
+    }
+    else if (res) {
+        Py_RETURN_TRUE;
+    }
+    Py_RETURN_FALSE;
+}
+
+static PyGetSetDef property_getsetlist[] = {
+    {"__isabstractmethod__",
+     (getter)property_get___isabstractmethod__, NULL,
+     NULL,
+     NULL},
+    {NULL} /* Sentinel */
+};
+
 PyDoc_STRVAR(property_doc,
 "property(fget=None, fset=None, fdel=None, doc=None) -> property attribute\n"
 "\n"
@@ -1445,7 +1482,7 @@ PyTypeObject PyProperty_Type = {
     0,                                          /* tp_iternext */
     property_methods,                           /* tp_methods */
     property_members,                           /* tp_members */
-    0,                                          /* tp_getset */
+    property_getsetlist,                        /* tp_getset */
     0,                                          /* tp_base */
     0,                                          /* tp_dict */
     property_descr_get,                         /* tp_descr_get */