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PEP 828: Fix return value crash of async generators #9

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Merged
ZeroIntensity merged 1 commit into from
Mar 11, 2026
Merged

PEP 828: Fix return value crash of async generators #9

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123 changes: 61 additions & 62 deletions Lib/test/test_async_yield_from.py
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Original file line number Diff line number Diff line change
Expand Up @@ -373,69 +373,68 @@ async def pex(e):
"value = eggs",
])

# @_async_test
# async def test_exception_value_crash(self):
# # There used to be a refcount error when the return value
# # stored in the StopAsyncIteration has a refcount of 1.
# async def g1():
# async yield from g2()
# async def g2():
# yield "g2"
# return [42]
# self.assertEqual([x async for x in g1()], ["g2"])

@_async_test
async def test_exception_value_crash(self):
# There used to be a refcount error when the return value
# stored in the StopAsyncIteration has a refcount of 1.
async def g1():
async yield from g2()
async def g2():
yield "g2"
return object()
self.assertEqual([x async for x in g1()], ["g2"])

# @_async_test
# async def test_generator_return_value(self):
# """
# Test generator return value
# """
# trace = []
# async def g1():
# trace.append("Starting g1")
# yield "g1 ham"
# ret = async yield from g2()
# trace.append("g2 returned %r" % (ret,))
# for v in 1, (2,), StopAsyncIteration(3):
# ret = async yield from g2(v)
# trace.append("g2 returned %r" % (ret,))
# yield "g1 eggs"
# trace.append("Finishing g1")
# async def g2(v = None):
# trace.append("Starting g2")
# yield "g2 spam"
# yield "g2 more spam"
# trace.append("Finishing g2")
# if v:
# return v
# async for x in g1():
# trace.append("Yielded %s" % (x,))
# self.assertEqual(trace,[
# "Starting g1",
# "Yielded g1 ham",
# "Starting g2",
# "Yielded g2 spam",
# "Yielded g2 more spam",
# "Finishing g2",
# "g2 returned None",
# "Starting g2",
# "Yielded g2 spam",
# "Yielded g2 more spam",
# "Finishing g2",
# "g2 returned 1",
# "Starting g2",
# "Yielded g2 spam",
# "Yielded g2 more spam",
# "Finishing g2",
# "g2 returned (2,)",
# "Starting g2",
# "Yielded g2 spam",
# "Yielded g2 more spam",
# "Finishing g2",
# "g2 returned StopAsyncIteration(3)",
# "Yielded g1 eggs",
# "Finishing g1",
# ])
@_async_test
async def test_generator_return_value(self):
"""
Test generator return value
"""
trace = []
async def g1():
trace.append("Starting g1")
yield "g1 ham"
ret = async yield from g2()
trace.append("g2 returned %r" % (ret,))
for v in 1, (2,), StopAsyncIteration(3):
ret = async yield from g2(v)
trace.append("g2 returned %r" % (ret,))
yield "g1 eggs"
trace.append("Finishing g1")
async def g2(v = None):
trace.append("Starting g2")
yield "g2 spam"
yield "g2 more spam"
trace.append("Finishing g2")
if v:
return v
async for x in g1():
trace.append("Yielded %s" % (x,))
self.assertEqual(trace,[
"Starting g1",
"Yielded g1 ham",
"Starting g2",
"Yielded g2 spam",
"Yielded g2 more spam",
"Finishing g2",
"g2 returned None",
"Starting g2",
"Yielded g2 spam",
"Yielded g2 more spam",
"Finishing g2",
"g2 returned 1",
"Starting g2",
"Yielded g2 spam",
"Yielded g2 more spam",
"Finishing g2",
"g2 returned (2,)",
"Starting g2",
"Yielded g2 spam",
"Yielded g2 more spam",
"Finishing g2",
"g2 returned StopAsyncIteration(3)",
"Yielded g1 eggs",
"Finishing g1",
])

@_async_test
async def test_delegation_of_anext_to_non_generator(self):
Expand Down
2 changes: 1 addition & 1 deletion Objects/exceptions.c
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Original file line number Diff line number Diff line change
Expand Up @@ -746,7 +746,7 @@ StopAsyncIteration_init(PyObject *op, PyObject *args, PyObject *kwds)
PyStopAsyncIterationObject *self = PyStopAsyncIterationObject_CAST(op);
Py_CLEAR(self->value);
if (size > 0) {
self->value = PyTuple_GET_ITEM(args, 0);
self->value = Py_NewRef(PyTuple_GET_ITEM(args, 0));
}
else {
self->value = Py_None;
Expand Down