After applying the patch from
LUCENE-3147, I added a line to make the test fail if it cannot remove its temporary directory.
I ran 'ant test' on linux 50 times, and it passed all 50 times.
But on windows, it failed often because of write.lock... this is because of unclosed writers in the test.
MockDirectoryWrapper is currently unaware of this write.lock, I think it should wrap the lockfactory so that .close() will fail if there are any outstanding locks.
Then hopefully these tests would fail on linux too.