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| author |   Nick Coghlan <ncoghlan@gmail.com> | 2014-01-22 23:04:37 +1000 |
|---|---|---|
| committer | Nick Coghlan <ncoghlan@gmail.com> | 2014-01-22 23:04:37 +1000 |
| commit | d58831e6886ce457626448c6c2efd1f4cd05dd3a (patch) | |
| tree | 2571c8d98d76f8ed944de9a517c546c53a25cf61 /Lib/contextlib.py | |
| parent | asyncio: Cleanup logging in BaseEventLoop._run_once() (diff) | |
| parent | Issue #20317: Don't create a reference loop in ExitStack (diff) | |
| download | cpython-d58831e6886ce457626448c6c2efd1f4cd05dd3a.tar.gz cpython-d58831e6886ce457626448c6c2efd1f4cd05dd3a.tar.bz2 cpython-d58831e6886ce457626448c6c2efd1f4cd05dd3a.zip | |
Merge #20317 from 3.3
Diffstat (limited to 'Lib/contextlib.py')
| -rw-r--r-- | Lib/contextlib.py | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/Lib/contextlib.py b/Lib/contextlib.py index d3219f6c150..ca7a79ddd19 100644 --- a/Lib/contextlib.py +++ b/Lib/contextlib.py @@ -298,11 +298,19 @@ class ExitStack(object): # we were actually nesting multiple with statements frame_exc = sys.exc_info()[1] def _fix_exception_context(new_exc, old_exc): + # Context isn't what we want, so find the end of the chain while 1: exc_context = new_exc.__context__ - if exc_context in (None, frame_exc): + if exc_context is old_exc: + # Context is already set correctly (see issue 20317) + return + if exc_context is None or exc_context is frame_exc: break + details = id(new_exc), id(old_exc), id(exc_context) + raise Exception(str(details)) new_exc = exc_context + # Change the end of the chain to point to the exception + # we expect it to reference new_exc.__context__ = old_exc # Callbacks are invoked in LIFO order to match the behaviour of |