Make sure that frame stack is in valid state should a recursion error happen when calling a class.

Author: markshannon

Lib/test/test_class.py

@@ -740,6 +740,25 @@ class A(0, 1, 2, 3, 4, 5, 6, 7, **d): pass
         class A(0, *range(1, 8), **d, foo='bar'): pass
         self.assertEqual(A, (tuple(range(8)), {'foo': 'bar'}))
 
+    def testClassCallRecursionLimit(self):
+        class C:
+            def __init__(self):
+                self.c = C()
+
+        try:
+            C()
+        except RecursionError:
+            # OK
+            pass
+        def add_one_level():
+            #Each call to C() consumes 2 levels, so offset by 1.
+            C()
+        try:
+            add_one_level()
+        except RecursionError:
+            # OK
+            pass
+
 
 if __name__ == '__main__':
     unittest.main()

Python/bytecodes.c

@@ -2924,9 +2924,6 @@ dummy_func(
                 goto error;
             }
             Py_DECREF(tp);
-            if (_Py_EnterRecursivePy(tstate)) {
-                goto exit_unwind;
-            }
             _PyInterpreterFrame *shim = _PyFrame_PushTrampolineUnchecked(
                 tstate, (PyCodeObject *)&_Py_InitCleanup, 1, 0);
             assert(_PyCode_CODE((PyCodeObject *)shim->f_executable)[1].op.code == EXIT_INIT_CHECK);
@@ -2950,6 +2947,10 @@ dummy_func(
             shim->previous = frame;
             frame = cframe.current_frame = init_frame;
             CALL_STAT_INC(inlined_py_calls);
+            /* Account for pushing the extra frame.
+             * We don't check recursion depth here,
+             * as it will be checked after start_frame */
+            tstate->py_recursion_remaining--;
             goto start_frame;
         }