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The fix for issue4050 broke some of my doctests. Minimal test:
import doctest, inspect
def test():
 '''
 >>> def x(): pass
 >>> inspect.getsource(x)
 'def x(): pass\\n'
 '''
doctest.run_docstring_examples(test, globals())
This works in 2.6, but not in 2.7. Reason is that inspect.getsourcefile() finds the fake filename '<docTest NoName[0]>', which it doesn't understand. In 2.6, inspect.getmodule() is also tried, which first looks at obj.__module__, and the filename can be derived from that. I suggest that inspect.getsourcefile() grows some code to use this trick if the filename seems fake (f[0] + f[-1] == '<>').

After chatting with Dirkjan, I misunderstood the impact of the patch. It only occurs when inspect.getsource() is called from a doctest, which isn't a very common situation.

Here's a test case that doesn't require doctest trickery:
import inspect, linecache
fn, source = '<test>', 'def x(): pass\n'
getlines = linecache.getlines
def monkey(filename, module_globals=None):
 if filename == fn:
 return source.splitlines(True)
 else:
 return getlines(filename, module_globals)
linecache.getlines = monkey
exec compile(source, fn, 'single') in globals()
inspect.getsource(x)

I don't understand why monkey patching linecache produces a valid test case. Can you explain?
Since I believe the same code/bugfix is in 3.x, I'm adding those versions.

Because doctest also monkeypatches linecache, and without monkeypatching linecache this also fails in 2.6.

Oh, right, I remember that now. Thanks.

Here's an attempted patch against 2.7. It seemed nice to put the test in test_doctest, but maybe it belongs in inspect...

Would it still be possible to get this into 2.7.2? It's a 2.6-2.7 regression, would be nice to fix, and it seems fairly low-impact.

- First line should be directly after the docstring
- One import per line
- Shouldn't this test be in test_inspect, since that's what you're changing?

I'm fine with moving the test; I put it in doctest because the inspect behavior we're relying upon here seems somewhat doctest-specific, and the test itself is a doctest. Do you want me to move it? I'll fix up the other things as well.

2011年6月9日 Dirkjan Ochtman <report@bugs.python.org>:
>
> Dirkjan Ochtman <dirkjan@ochtman.nl> added the comment:
>
> I'm fine with moving the test; I put it in doctest because the inspect behavior we're relying upon here seems somewhat doctest-specific, and the test itself is a doctest. Do you want me to move it? I'll fix up the other things as well.
I would prefer that if the bug is somehow reintroduced, test_inspect
instead of test_doctest fails.

Here's a fresh patch.

New changeset 527c40add91d by Benjamin Peterson in branch '2.7':
allow "fake" filenames in findsource (closes #9284)
http://hg.python.org/cpython/rev/527c40add91d
New changeset 6cc4579dca02 by Benjamin Peterson in branch '3.2':
allow "fake" filenames in findsource (closes #9284)
http://hg.python.org/cpython/rev/6cc4579dca02
New changeset f05affb0bb2a by Benjamin Peterson in branch 'default':
merge 3.2 (#9284)
http://hg.python.org/cpython/rev/f05affb0bb2a