$ python2.5 -c 'print((1, 2, 3))' > /dev/full || echo error status
close failed: [Errno 28] No space left on device
$

The above sequence should also output 'error status' before the next
prompt.  That is, python should not be returning EXIT_SUCCESS in this
situation.

Oops, I should have used the old python print syntax.  Nonetheless, the
behavior is the same:

$ python2.5 -c 'print 1, 2, 3' > /dev/full || echo error status
close failed: [Errno 28] No space left on device
$

Python 2.6, from #5320:

$ python2.6 -c 'print 1, 2, 3' > /dev/full || echo error status
close failed in file object destructor:
Error in sys.excepthook:

Original exception was:
$

Python 3.1 doesn't output anything and also doesn't set an error status.

Georg, are you saying that there is or is not a problem with 2.6 (which is beyond non-critical bug fixes) and/or 3.1?

Here is a possible patch for 3.x.
It doesn't change the return status of the process, though.

I've committed the py3k fix in r83854 (3.1 in r83855).
As for 2.6/2.7, I've finally diagnosed the problem: 2.6 and upwards use PyErr_Print() in the file destructor, but the sys.stderr and sys.excepthook objects are already None at that time (because of interpreter shutdown). Therefore the error can't be printed out.
2.5 and earlier used a direct fprintf() of the errno code to stderr.

I propose to ignore the 2.6/2.7 issue of the error not being printed properly, since it only happens at shutdown with a misbehaving stdout, which is not very common.

As for the issue of the stdout error not being reported in the process return code, this would be possible in 3.x, although it would involve changing the signature of Py_Finalize() to include a return status (it currently returns void).

New changeset 150e096095e5 by Antoine Pitrou in branch '3.2':
Issue #13444: When stdout has been closed explicitly, we should not attempt to flush it at shutdown and print an error.
http://hg.python.org/cpython/rev/150e096095e5

New changeset 37300a1df7d7 by Antoine Pitrou in branch 'default':
Issue #13444: When stdout has been closed explicitly, we should not attempt to flush it at shutdown and print an error.
http://hg.python.org/cpython/rev/37300a1df7d7