From e757c76589d927e25c1202ef2482a1cfd0757fba Mon Sep 17 00:00:00 2001 From: Chris Jerdonek Date: Wed, 29 Apr 2020 22:21:08 -0700 Subject: [PATCH 1/4] Add a failing test for issue 29587. --- Lib/test/test_generators.py | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/Lib/test/test_generators.py b/Lib/test/test_generators.py index 3e42bc6b69a819..4d96f44b150622 100644 --- a/Lib/test/test_generators.py +++ b/Lib/test/test_generators.py @@ -316,6 +316,23 @@ def g(): 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(): From 57597f2738c7fe09d0a716dca72bd8feb66f447e Mon Sep 17 00:00:00 2001 From: Chris Jerdonek Date: Thu, 30 Apr 2020 00:31:39 -0700 Subject: [PATCH 2/4] bpo-29587: set exc.__context__ when calling gen.throw() (GH-19811) Before this commit, if an exception was active inside a generator when calling gen.throw(), then that exception was lost (i.e. there was no implicit exception chaining). This commit fixes that. --- .../2020-04-30-00-50-25.bpo-29587.oEwSq.rst | 1 + Objects/genobject.c | 6 ++++++ 2 files changed, 7 insertions(+) create mode 100644 Misc/NEWS.d/next/Core and Builtins/2020-04-30-00-50-25.bpo-29587.oEwSq.rst 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 00000000000000..f44aa360cc2ef3 --- /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 6e36690b65148a..289ed79aa28a65 100644 --- a/Objects/genobject.c +++ b/Objects/genobject.c @@ -512,6 +512,12 @@ _gen_throw(PyGenObject *gen, int close_on_genexit, } PyErr_Restore(typ, val, tb); + if (gen->gi_exc_state.exc_type) { + Py_INCREF(gen->gi_exc_state.exc_type); + Py_XINCREF(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: From c321731d95c121e76e377812ba522ad268476519 Mon Sep 17 00:00:00 2001 From: Chris Jerdonek Date: Fri, 1 May 2020 01:09:34 -0700 Subject: [PATCH 3/4] Wrap the long line. --- Objects/genobject.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/Objects/genobject.c b/Objects/genobject.c index 289ed79aa28a65..65ad9d4d3d07b0 100644 --- a/Objects/genobject.c +++ b/Objects/genobject.c @@ -516,7 +516,8 @@ _gen_throw(PyGenObject *gen, int close_on_genexit, Py_INCREF(gen->gi_exc_state.exc_type); Py_XINCREF(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); + _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); From 1bf33096f1b0c658801c1b16efc2d15d93d85109 Mon Sep 17 00:00:00 2001 From: Chris Jerdonek Date: Fri, 1 May 2020 01:16:26 -0700 Subject: [PATCH 4/4] Address the CI failures on Fedora, etc. --- Objects/genobject.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/Objects/genobject.c b/Objects/genobject.c index 65ad9d4d3d07b0..41a63ae2e666aa 100644 --- a/Objects/genobject.c +++ b/Objects/genobject.c @@ -512,9 +512,11 @@ _gen_throw(PyGenObject *gen, int close_on_genexit, } PyErr_Restore(typ, val, tb); - if (gen->gi_exc_state.exc_type) { + /* 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_XINCREF(gen->gi_exc_state.exc_value); + 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);