diff --git a/Lib/test/test_generators.py b/Lib/test/test_generators.py index 3e42bc6b69a..4d96f44b150 100644 --- a/Lib/test/test_generators.py +++ b/Lib/test/test_generators.py @@ -316,6 +316,23 @@ class ExceptionTest(unittest.TestCase): self.assertEqual(cm.exception.value.value, 2) +class GeneratorThrowTest(unittest.TestCase): + + def test_exception_context_set(self): + def f(): + try: + raise KeyError('a') + except Exception: + yield + + gen = f() + gen.send(None) + with self.assertRaises(ValueError) as cm: + gen.throw(ValueError) + context = cm.exception.__context__ + self.assertEqual((type(context), context.args), (KeyError, ('a',))) + + class YieldFromTests(unittest.TestCase): def test_generator_gi_yieldfrom(self): def a(): diff --git a/Misc/NEWS.d/next/Core and Builtins/2020-04-30-00-50-25.bpo-29587.oEwSq.rst b/Misc/NEWS.d/next/Core and Builtins/2020-04-30-00-50-25.bpo-29587.oEwSq.rst new file mode 100644 index 00000000000..f44aa360cc2 --- /dev/null +++ b/Misc/NEWS.d/next/Core and Builtins/2020-04-30-00-50-25.bpo-29587.oEwSq.rst @@ -0,0 +1 @@ +Enable implicit exception chaining when calling :meth:`generator.throw`. diff --git a/Objects/genobject.c b/Objects/genobject.c index 6e36690b651..41a63ae2e66 100644 --- a/Objects/genobject.c +++ b/Objects/genobject.c @@ -512,6 +512,15 @@ throw_here: } PyErr_Restore(typ, val, tb); + /* XXX Should we also handle the case where exc_type is true and + exc_value is false? */ + if (gen->gi_exc_state.exc_type && gen->gi_exc_state.exc_value) { + Py_INCREF(gen->gi_exc_state.exc_type); + Py_INCREF(gen->gi_exc_state.exc_value); + Py_XINCREF(gen->gi_exc_state.exc_traceback); + _PyErr_ChainExceptions(gen->gi_exc_state.exc_type, + gen->gi_exc_state.exc_value, gen->gi_exc_state.exc_traceback); + } return gen_send_ex(gen, Py_None, 1, 0); failed_throw: