fix usage of Py_BEGIN_CRITICAL_SECTION

Author: albertedwardson

Objects/codeobject.c

@@ -206,17 +206,18 @@ static int
 intern_constants(PyObject *tuple, int *modified)
 {
     PyInterpreterState *interp = _PyInterpreterState_GET();
-    // copypaste from unicodeobject.c
     PyObject *interned_dict = _Py_INTERP_CACHED_OBJECT(interp, interned_strings);
-    Py_BEGIN_CRITICAL_SECTION(interned_dict);
     Py_INCREF(interned_dict);
     for (Py_ssize_t i = PyTuple_GET_SIZE(tuple); --i >= 0; ) {
         PyObject *v = PyTuple_GET_ITEM(tuple, i);
         if (PyUnicode_CheckExact(v) && PyUnicode_GET_LENGTH(v) > 1) {
             if (PyUnicode_CHECK_INTERNED(v) != 0) {
                 continue;
             }
-            PyObject *interned = PyDict_GetItemWithError(interned_dict, v);
+            PyObject *interned;
+            Py_BEGIN_CRITICAL_SECTION(interned_dict);
+            interned = PyDict_GetItemWithError(interned_dict, v);
+            Py_END_CRITICAL_SECTION();
             if (interned == NULL && PyErr_Occurred()) {
                 goto error;
             }
@@ -327,12 +328,10 @@ intern_constants(PyObject *tuple, int *modified)
         }
 #endif
     }
-    Py_END_CRITICAL_SECTION();
     Py_DECREF(interned_dict);
     return 0;
 
 error:
-    Py_END_CRITICAL_SECTION();
     Py_DECREF(interned_dict);
     return -1;
 }