gh-99540: Constant hash for _PyNone_Type to aid reproducibility (GH-99541)

yonillasky · web-flow · commit 432117cd1f59 · 2022-12-16T12:36:13.000-08:00
Needed for ASLR builds of Python.
diff --git a/Misc/NEWS.d/next/Core and Builtins/2022-12-10-20-00-13.gh-issue-99540.ZZZHeP.rst b/Misc/NEWS.d/next/Core and Builtins/2022-12-10-20-00-13.gh-issue-99540.ZZZHeP.rst
@@ -0,0 +1 @@
+``None`` now hashes to a constant value. This is not a requirements change.
diff --git a/Objects/object.c b/Objects/object.c
@@ -1641,6 +1641,11 @@ none_bool(PyObject *v)
     return 0;
 }
 
+static Py_hash_t none_hash(PyObject *v)
+{
+    return 0xFCA86420;
+}
+
 static PyNumberMethods none_as_number = {
     0,                          /* nb_add */
     0,                          /* nb_subtract */
@@ -1692,7 +1697,7 @@ PyTypeObject _PyNone_Type = {
     &none_as_number,    /*tp_as_number*/
     0,                  /*tp_as_sequence*/
     0,                  /*tp_as_mapping*/
-    0,                  /*tp_hash */
+    (hashfunc)none_hash,/*tp_hash */
     0,                  /*tp_call */
     0,                  /*tp_str */
     0,                  /*tp_getattro */

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1 @@`
	`1`	+``None`` now hashes to a constant value. This is not a requirements change.