Fix frame termination

Author: pablogsal

Python/pylifecycle.c

@@ -2571,7 +2571,7 @@ Py_EndInterpreter(PyThreadState *tstate)
     if (tstate != _PyThreadState_GET()) {
         Py_FatalError("thread is not current");
     }
-    if (tstate->current_frame != NULL) {
+    if (tstate->current_frame != tstate->base_frame) {
         Py_FatalError("thread still has a frame");
     }
     interp->finalizing = 1;

Python/pystate.c

@@ -1684,7 +1684,7 @@ PyThreadState_Clear(PyThreadState *tstate)
 
     int verbose = _PyInterpreterState_GetConfig(tstate->interp)->verbose;
 
-    if (verbose && tstate->current_frame != NULL) {
+    if (verbose && tstate->current_frame != tstate->base_frame) {
         /* bpo-20526: After the main thread calls
            _PyInterpreterState_SetFinalizing() in Py_FinalizeEx()
            (or in Py_EndInterpreter() for subinterpreters),