Remove redundant Py_None check, add None tests, add assert

Author: brianschubert

Lib/test/test__interpreters.py

@@ -490,6 +490,17 @@ def test_signatures(self):
         with self.assertRaisesRegex(TypeError, msg):
             _interpreters.set___main___attrs(self.id, 1)
 
+    def test_invalid_shared_none(self):
+        msg = r'must be dict, not None'
+        with self.assertRaisesRegex(TypeError, msg):
+            _interpreters.exec(self.id, 'a', shared=None)
+        with self.assertRaisesRegex(TypeError, msg):
+            _interpreters.run_string(self.id, 'a', shared=None)
+        with self.assertRaisesRegex(TypeError, msg):
+            _interpreters.run_func(self.id, lambda: None, shared=None)
+        with self.assertRaisesRegex(TypeError, msg):
+            _interpreters.set___main___attrs(self.id, None)
+
     def test_invalid_shared_encoding(self):
         # See https://github.com/python/cpython/issues/127196
         bad_shared = {"\uD82A": 0}

Modules/_interpretersmodule.c

@@ -1054,16 +1054,14 @@ interp_set___main___attrs(PyObject *self, PyObject *args, PyObject *kwargs)
     }
 
     // Check the updates.
-    if (updates != Py_None) {
-        Py_ssize_t size = PyDict_Size(updates);
-        if (size < 0) {
-            return NULL;
-        }
-        if (size == 0) {
-            PyErr_SetString(PyExc_ValueError,
-                            "arg 2 must be a non-empty dict");
-            return NULL;
-        }
+    Py_ssize_t size = PyDict_Size(updates);
+    if (size < 0) {
+        return NULL;
+    }
+    if (size == 0) {
+        PyErr_SetString(PyExc_ValueError,
+                        "arg 2 must be a non-empty dict");
+        return NULL;
     }
 
     _PyXI_session *session = _PyXI_NewSession();

Python/crossinterp.c

@@ -2617,6 +2617,7 @@ _PyXI_Enter(_PyXI_session *session,
     // Convert the attrs for cross-interpreter use.
     _PyXI_namespace *sharedns = NULL;
     if (nsupdates != NULL) {
+        assert(PyDict_Check(nsupdates));
         Py_ssize_t len = PyDict_Size(nsupdates);
         if (len < 0) {
             if (result != NULL) {