close() will now raise an IOError if any operations on the file object
are currently in progress in other threads.
Most code was written by Antoine Pitrou (pitrou). Additional testing,
documentation and test suite cleanup done by me (gregory.p.smith).
Fixes issue 815646 and 595601 (as well as many other bugs and
references to this problem dating back to the dawn of Python).
test clean up after itself appears to fix the test failures
when test_optparse follows test_file.
test_main(): Get rid of TESTFN no matter what. That's
also enough to fix the mystery failures. Doesn't hurt
to fix them twice :-)
Since test_file is implicated in mysterious test failures
when followed by test_optparse, if I had any brains I'd
look at the checkin that last changed test_file ;-)
like cause the interpreter to exit abruptly. If there's a way to fix this,
it would be good to really fix it. It could just be the operation of the
std C library and we just aren't supposed to do that.
When the test case is skipped, we print a message so the user can check
for themselves.
test_file to fail on Windows in reality (can't delete
a still-open file), but a new bare "except:" hid that
test_file failed on Windows, and leaving behind the
still-open TESTFN caused a cascade of bogus failures
in later tests.
So, close the file, and stop hiding failure to unlink.
readline/readlines/read/readinto, loudly break by raising ValueError, rather
than silently deliver data out of order or hitting EOF prematurely.
Probably not a bugfix candidate, even though it affects no 'working' code.
