python
diff --git a/‎Include/internal/pycore_object.h
Lines changed: 1 addition & 0 deletions b/‎Include/internal/pycore_object.h
Lines changed: 1 addition & 0 deletions
diff --git a/‎Lib/test/test_capi/test_misc.py
Lines changed: 49 additions & 0 deletions b/‎Lib/test/test_capi/test_misc.py
Lines changed: 49 additions & 0 deletions
diff --git a/‎Modules/_testcapimodule.c
Lines changed: 41 additions & 0 deletions b/‎Modules/_testcapimodule.c
Lines changed: 41 additions & 0 deletions
diff --git a/‎Objects/object.c
Lines changed: 21 additions & 1 deletion b/‎Objects/object.c
Lines changed: 21 additions & 1 deletion
diff --git a/‎Python/pylifecycle.c
Lines changed: 2 additions & 0 deletions b/‎Python/pylifecycle.c
Lines changed: 2 additions & 0 deletions
diff --git a/‎Python/pystate.c
Lines changed: 1 addition & 0 deletions b/‎Python/pystate.c
Lines changed: 1 addition & 0 deletions
@@ -173,6 +173,7 @@ _PyType_HasFeature(PyTypeObject *type, unsigned long feature) {
 
 extern void _PyType_InitCache(PyInterpreterState *interp);
 
+extern void _PyObject_InitState(PyInterpreterState *interp);
 
 /* Inline functions trading binary compatibility for speed:
    _PyObject_Init() is the fast version of PyObject_Init(), and
 
@@ -51,6 +51,8 @@
 import _testinternalcapi
 
 
+NULL = None
+
 def decode_stderr(err):
     return err.decode('utf-8', 'replace').replace('\r', '')
 
@@ -2576,5 +2578,52 @@ def testfunc(it):
             with self.assertRaises(StopIteration):
                 next(it)
 
+    def test_sys_getobject(self):
+        getobject = _testcapi.sys_getobject
+
+        self.assertIs(getobject(b'stdout'), sys.stdout)
+        with support.swap_attr(sys, '\U0001f40d', 42):
+            self.assertEqual(getobject('\U0001f40d'.encode()), 42)
+
+        self.assertIs(getobject(b'nonexisting'), AttributeError)
+
+        with support.catch_unraisable_exception() as cm:
+            self.assertIs(getobject(b'\xff'), AttributeError)
+            self.assertEqual(cm.unraisable.exc_type, UnicodeDecodeError)
+            self.assertRegex(str(cm.unraisable.exc_value),
+                             "'utf-8' codec can't decode")
+
+        # CRASHES getobject(NULL)
+
+    def test_sys_setobject(self):
+        setobject = _testcapi.sys_setobject
+
+        value = ['value']
+        value2 = ['value2']
+        try:
+            self.assertEqual(setobject(b'newattr', value), 0)
+            self.assertIs(sys.newattr, value)
+            self.assertEqual(setobject(b'newattr', value2), 0)
+            self.assertIs(sys.newattr, value2)
+            self.assertEqual(setobject(b'newattr', NULL), 0)
+            self.assertFalse(hasattr(sys, 'newattr'))
+            self.assertEqual(setobject(b'newattr', NULL), 0)
+        finally:
+            with contextlib.suppress(AttributeError):
+                del sys.newattr
+        try:
+            self.assertEqual(setobject('\U0001f40d'.encode(), value), 0)
+            self.assertIs(getattr(sys, '\U0001f40d'), value)
+            self.assertEqual(setobject('\U0001f40d'.encode(), NULL), 0)
+            self.assertFalse(hasattr(sys, '\U0001f40d'))
+        finally:
+            with contextlib.suppress(AttributeError):
+                delattr(sys, '\U0001f40d')
+
+        with self.assertRaises(UnicodeDecodeError):
+            setobject(b'\xff', value)
+        # CRASHES setobject(NULL, value)
+
+
 if __name__ == "__main__":
     unittest.main()
@@ -44,6 +44,16 @@
 // Include definitions from there.
 #include "_testcapi/parts.h"
 
+#define NULLABLE(x) do { if (x == Py_None) x = NULL; } while (0);
+
+#define RETURN_INT(value) do {          \
+        int _ret = (value);             \
+        if (_ret == -1) {               \
+            return NULL;                \
+        }                               \
+        return PyLong_FromLong(_ret);   \
+    } while (0)
+
 // Forward declarations
 static struct PyModuleDef _testcapimodule;
 static PyObject *TestError;     /* set to exception object in init */
@@ -3501,6 +3511,35 @@ test_dict_capi(PyObject *Py_UNUSED(module), PyObject *Py_UNUSED(args))
 }
 
 
+static PyObject *
+sys_getobject(PyObject *Py_UNUSED(module), PyObject *arg)
+{
+    const char *name;
+    Py_ssize_t size;
+    if (!PyArg_Parse(arg, "z#", &name, &size)) {
+        return NULL;
+    }
+    PyObject *result = PySys_GetObject(name);
+    if (result == NULL) {
+        result = PyExc_AttributeError;
+    }
+    return Py_NewRef(result);
+}
+
+static PyObject *
+sys_setobject(PyObject *Py_UNUSED(module), PyObject *args)
+{
+    const char *name;
+    Py_ssize_t size;
+    PyObject *value;
+    if (!PyArg_ParseTuple(args, "z#O", &name, &size, &value)) {
+        return NULL;
+    }
+    NULLABLE(value);
+    RETURN_INT(PySys_SetObject(name, value));
+}
+
+
 static PyMethodDef TestMethods[] = {
     {"set_errno",               set_errno,                       METH_VARARGS},
     {"test_config",             test_config,                     METH_NOARGS},
@@ -3636,6 +3675,8 @@ static PyMethodDef TestMethods[] = {
     {"check_pyimport_addmodule", check_pyimport_addmodule, METH_VARARGS},
     {"test_weakref_capi", test_weakref_capi, METH_NOARGS},
     {"test_dict_capi", test_dict_capi, METH_NOARGS},
+    {"sys_getobject", sys_getobject, METH_O},
+    {"sys_setobject", sys_setobject, METH_VARARGS},
     {NULL, NULL} /* sentinel */
 };
 
 
@@ -162,6 +162,14 @@ _PyDebug_PrintTotalRefs(void) {
 
 #define REFCHAIN(interp) &interp->object_state.refchain
 
+static inline void
+init_refchain(PyInterpreterState *interp)
+{
+    PyObject *refchain = REFCHAIN(interp);
+    refchain->_ob_prev = refchain;
+    refchain->_ob_next = refchain;
+}
+
 /* Insert op at the front of the list of all objects.  If force is true,
  * op is added even if _ob_prev and _ob_next are non-NULL already.  If
  * force is false amd _ob_prev or _ob_next are non-NULL, do nothing.
@@ -2012,6 +2020,18 @@ PyObject _Py_NotImplementedStruct = {
     &_PyNotImplemented_Type
 };
 
+
+void
+_PyObject_InitState(PyInterpreterState *interp)
+{
+#ifdef Py_TRACE_REFS
+    if (!_Py_IsMainInterpreter(interp)) {
+        init_refchain(interp);
+    }
+#endif
+}
+
+
 extern PyTypeObject _Py_GenericAliasIterType;
 extern PyTypeObject _PyMemoryIter_Type;
 extern PyTypeObject _PyLineIterator;
@@ -2319,7 +2339,7 @@ _Py_GetObjects(PyObject *self, PyObject *args)
 
 #undef REFCHAIN
 
-#endif
+#endif  /* Py_TRACE_REFS */
 
 
 /* Hack to force loading of abstract.o */
 
@@ -2075,6 +2075,8 @@ new_interpreter(PyThreadState **tstate_p, const PyInterpreterConfig *config)
     }
     has_gil = 1;
 
+    /* No objects have been created yet. */
+
     status = pycore_interp_init(tstate);
     if (_PyStatus_EXCEPTION(status)) {
         goto error;
 
@@ -674,6 +674,7 @@ init_interpreter(PyInterpreterState *interp,
                 _obmalloc_pools_INIT(interp->obmalloc.pools);
         memcpy(&interp->obmalloc.pools.used, temp, sizeof(temp));
     }
+    _PyObject_InitState(interp);
 
     _PyEval_InitState(interp, pending_lock);
     _PyGC_InitState(&interp->gc);