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

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
new file mode 100644 (file)
index 0000000..ae043f3
--- /dev/null
+++ 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
index 687bd36d2b4af1e5b5b08e1b3fdf4efbc491c75d..028b0edc91115518103d020f69a5c1d8aae1c336 100644 (file)
--- 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 */