https://github.com/python/cpython/commit/1cc5c943c007b92116f06b3ec8e71f2a510... commit: 1cc5c943c007b92116f06b3ec8e71f2a510d1898 branch: 3.8 author: Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com> committer: miss-islington <31488909+miss-islington@users.noreply.github.com> date: 2020-11-30T17:53:40-08:00 summary: bpo-42482: remove reference to exc_traceback from TracebackException (GH-23531) (cherry picked from commit 427613f005f0f412d12f0d775d2b609bae0ae1ad) Co-authored-by: Irit Katriel <iritkatriel@yahoo.com> files: A Misc/NEWS.d/next/Library/2020-11-27-16-46-58.bpo-42482.EJC3sd.rst M Lib/test/test_traceback.py M Lib/traceback.py diff --git a/Lib/test/test_traceback.py b/Lib/test/test_traceback.py index 8a80d5802bb41..a5ba6090cf08d 100644 --- a/Lib/test/test_traceback.py +++ b/Lib/test/test_traceback.py @@ -1083,6 +1083,18 @@ def test_context(self): self.assertEqual(exc_info[0], exc.exc_type) self.assertEqual(str(exc_info[1]), str(exc)) + def test_no_refs_to_exception_and_traceback_objects(self): + try: + 1/0 + except Exception: + exc_info = sys.exc_info() + + refcnt1 = sys.getrefcount(exc_info[1]) + refcnt2 = sys.getrefcount(exc_info[2]) + exc = traceback.TracebackException(*exc_info) + self.assertEqual(sys.getrefcount(exc_info[1]), refcnt1) + self.assertEqual(sys.getrefcount(exc_info[2]), refcnt2) + def test_comparison_basic(self): try: 1/0 @@ -1133,6 +1145,16 @@ def raise_with_locals(): exc7 = traceback.TracebackException(*exc_info, limit=-2, capture_locals=True) self.assertNotEqual(exc6, exc7) + def test_comparison_equivalent_exceptions_are_equal(self): + excs = [] + for _ in range(2): + try: + 1/0 + except: + excs.append(traceback.TracebackException(*sys.exc_info())) + self.assertEqual(excs[0], excs[1]) + self.assertEqual(list(excs[0].format()), list(excs[1].format())) + def test_unhashable(self): class UnhashableException(Exception): def __eq__(self, other): diff --git a/Lib/traceback.py b/Lib/traceback.py index 5ef3be74be74a..19de84b26bf35 100644 --- a/Lib/traceback.py +++ b/Lib/traceback.py @@ -500,7 +500,6 @@ def __init__(self, exc_type, exc_value, exc_traceback, *, limit=None, _seen=_seen) else: context = None - self.exc_traceback = exc_traceback self.__cause__ = cause self.__context__ = context self.__suppress_context__ = \ @@ -608,7 +607,7 @@ def format(self, *, chain=True): not self.__suppress_context__): yield from self.__context__.format(chain=chain) yield _context_message - if self.exc_traceback is not None: + if self.stack: yield 'Traceback (most recent call last):\n' - yield from self.stack.format() + yield from self.stack.format() yield from self.format_exception_only() diff --git a/Misc/NEWS.d/next/Library/2020-11-27-16-46-58.bpo-42482.EJC3sd.rst b/Misc/NEWS.d/next/Library/2020-11-27-16-46-58.bpo-42482.EJC3sd.rst new file mode 100644 index 0000000000000..79afa654f352e --- /dev/null +++ b/Misc/NEWS.d/next/Library/2020-11-27-16-46-58.bpo-42482.EJC3sd.rst @@ -0,0 +1 @@ +:class:`~traceback.TracebackException` no longer holds a reference to the exception's traceback object. Consequently, instances of TracebackException for equivalent but non-equal exceptions now compare as equal. \ No newline at end of file