r84784 sets os.path.supports_unicode_filenames to True on Mac OS X (macpath module).

About test_supports_unicode_filenames.patch. test_unicode_listdir() is wrong: os.listdir(str) always return str (see r84701). "verify that the new file's name is equal to the name we tried" check of test_unicode_filename() is also wrong: newfile.name is always equal to fname, it doesn't depend on support_unicode_filenames. Since the test is wrong, I don't want to commit it. test_pep277 is enough to test the creation of files with unicode names.

I don't see anything else to do now, so I close this issue. Reopen it if I forgot something, or open a new issue.