Issue #26494: Fixed crash on iterating exhausting iterators. · pythoncapi/cpython@ab479c4 · GitHub
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Issue python#26494: Fixed crash on iterating exhausting iterators.
Affected classes are generic sequence iterators, iterators of str, bytes, bytearray, list, tuple, set, frozenset, dict, OrderedDict, corresponding views and os.scandir() iterator.
2 parents fe4c012 + fbb1c5e commit ab479c4

19 files changed

Lines changed: 92 additions & 22 deletions

‎Lib/test/seq_tests.py‎

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‎Lib/test/support/__init__.py‎

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@@ -2432,3 +2432,22 @@ def run_in_subinterp(code):
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"memory allocations")
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import _testcapi
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return _testcapi.run_in_subinterp(code)
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def check_free_after_iterating(test, iter, cls, args=()):
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class A(cls):
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def __del__(self):
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nonlocal done
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done = True
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try:
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next(it)
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except StopIteration:
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pass
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done = False
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it = iter(A(*args))
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# Issue 26494: Shouldn't crash
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test.assertRaises(StopIteration, next, it)
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# The sequence should be deallocated just after the end of iterating
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gc_collect()
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test.assertTrue(done)

‎Lib/test/test_bytes.py‎

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@@ -761,6 +761,10 @@ def test_find_etc_raise_correct_error_messages(self):
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self.assertRaisesRegex(TypeError, r'\bendswith\b', b.endswith,
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x, None, None, None)
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def test_free_after_iterating(self):
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test.support.check_free_after_iterating(self, iter, self.type2test)
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test.support.check_free_after_iterating(self, reversed, self.type2test)
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class BytesTest(BaseBytesTest, unittest.TestCase):
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type2test = bytes

‎Lib/test/test_deque.py‎

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Original file line numberDiff line numberDiff line change
@@ -918,6 +918,10 @@ def test_subscript(self):
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# For now, bypass tests that require slicing
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pass
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def test_free_after_iterating(self):
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# For now, bypass tests that require slicing
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self.skipTest("Exhausted deque iterator doesn't free a deque")
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#==============================================================================
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libreftest = """

‎Lib/test/test_dict.py‎

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Original file line numberDiff line numberDiff line change
@@ -954,6 +954,12 @@ def __eq__(self, o):
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d = {X(): 0, 1: 1}
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self.assertRaises(RuntimeError, d.update, other)
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def test_free_after_iterating(self):
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support.check_free_after_iterating(self, iter, dict)
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support.check_free_after_iterating(self, lambda d: iter(d.keys()), dict)
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support.check_free_after_iterating(self, lambda d: iter(d.values()), dict)
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support.check_free_after_iterating(self, lambda d: iter(d.items()), dict)
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from test import mapping_tests
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class GeneralMappingTests(mapping_tests.BasicTestMappingProtocol):

‎Lib/test/test_iter.py‎

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@@ -3,6 +3,7 @@
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import sys
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import unittest
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from test.support import run_unittest, TESTFN, unlink, cpython_only
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from test.support import check_free_after_iterating
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import pickle
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import collections.abc
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@@ -980,6 +981,9 @@ def test_iter_neg_setstate(self):
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self.assertEqual(next(it), 0)
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self.assertEqual(next(it), 1)
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def test_free_after_iterating(self):
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check_free_after_iterating(self, iter, SequenceClass, (0,))
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def test_main():
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run_unittest(TestCase)

‎Lib/test/test_ordered_dict.py‎

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@@ -608,6 +608,12 @@ class A:
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gc.collect()
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self.assertIsNone(r())
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def test_free_after_iterating(self):
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support.check_free_after_iterating(self, iter, self.OrderedDict)
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support.check_free_after_iterating(self, lambda d: iter(d.keys()), self.OrderedDict)
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support.check_free_after_iterating(self, lambda d: iter(d.values()), self.OrderedDict)
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support.check_free_after_iterating(self, lambda d: iter(d.items()), self.OrderedDict)
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class PurePythonOrderedDictTests(OrderedDictTests, unittest.TestCase):
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‎Lib/test/test_set.py‎

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Original file line numberDiff line numberDiff line change
@@ -364,6 +364,9 @@ class C(object):
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gc.collect()
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self.assertTrue(ref() is None, "Cycle was not collected")
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def test_free_after_iterating(self):
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support.check_free_after_iterating(self, iter, self.thetype)
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class TestSet(TestJointOps, unittest.TestCase):
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thetype = set
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basetype = set

‎Lib/test/test_unicode.py‎

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Original file line numberDiff line numberDiff line change
@@ -2729,6 +2729,10 @@ def test_pep393_utf8_caching_bug(self):
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# Check that the second call returns the same result
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self.assertEqual(getargs_s_hash(s), chr(k).encode() * (i + 1))
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def test_free_after_iterating(self):
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support.check_free_after_iterating(self, iter, str)
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support.check_free_after_iterating(self, reversed, str)
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class StringModuleTest(unittest.TestCase):
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def test_formatter_parser(self):

‎Misc/NEWS‎

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