[Python-Dev] test_urllibnet failing on Windows

[Tim Peters]

I'm not familiar with this test.

In a release build:

"""
C:\Code\python\PCbuild>python ../lib/test/test_urllibnet.py
testURLread (__main__.URLTimeoutTest) ... ok
test_bad_address (__main__.urlopenNetworkTests) ... ok
test_basic (__main__.urlopenNetworkTests) ... ok
test_fileno (__main__.urlopenNetworkTests) ... ERROR
test_geturl (__main__.urlopenNetworkTests) ... ok
test_info (__main__.urlopenNetworkTests) ... ok
test_readlines (__main__.urlopenNetworkTests) ... ok
test_basic (__main__.urlretrieveNetworkTests) ... ok
test_header (__main__.urlretrieveNetworkTests) ... ok
test_specified_path (__main__.urlretrieveNetworkTests) ... ok

======================================================================
ERROR: test_fileno (__main__.urlopenNetworkTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "../lib/test/test_urllibnet.py", line 91, in test_fileno
    FILE = os.fdopen(fd)
OSError: (0, 'Error')

----------------------------------------------------------------------
Ran 10 tests in 7.081s

FAILED (errors=1)
Traceback (most recent call last):
  File "../lib/test/test_urllibnet.py", line 149, in ?
    test_main()
  File "../lib/test/test_urllibnet.py", line 146, in test_main
    urlretrieveNetworkTests)
  File "C:\Code\python\lib\test\test_support.py", line 259, in run_unittest
    run_suite(suite, testclass)
  File "C:\Code\python\lib\test\test_support.py", line 247, in run_suite
    raise TestFailed(err)
test.test_support.TestFailed: Traceback (most recent call last):
  File "../lib/test/test_urllibnet.py", line 91, in test_fileno
    FILE = os.fdopen(fd)
OSError: (0, 'Error')
"""

In a debug build:

"""
C:\Code\python\PCbuild>python_d ../lib/test/test_urllibnet.py
testURLread (__main__.URLTimeoutTest) ... ok
test_bad_address (__main__.urlopenNetworkTests) ... ok
test_basic (__main__.urlopenNetworkTests) ... ok
test_fileno (__main__.urlopenNetworkTests) ...
"""

and there it dies with an assertion error in the bowels of Microsoft's
fdopen.c.  That's called by Python's posix_fdopen, here:

	fp = fdopen(fd, mode);

At this point, fd is 436.  MS's fdopen is unhappy because only 32 handles
actually exist at this point, and 436 is bigger than that.  In the release
build, the MS assert doesn't (of course) trigger; instead, that 436 >= 32
causes MS's fdopen to return NULL.