akira added the comment: yes, line_buffering=(bufsize == 1) is necessary to support the current Python io implementation or if C implementation is fixed to avoid buffer.flush() on every write with write_through=True -- otherwise bufsize is not respected in text mode (it would always mean bufsize=0).
Note: the current patch for issue #21396 (making C and Python io do the same thing) may break subprocess code with universal_newlines=True that expects (incorrectly) bufsize=0 by default -- as test_universal_newlines had (enabling universal_newlines shouldn't switch from bufsize=-1 to bufsize=0). <-- XXX backward compatibility issue! > Perhaps you can avoid the 10 s deadlock timeout and threading in your > test by closing the underlying input pipe file descriptor (or raw file > object), without flushing it. It is a good idea. There could be portability issues with the test: it relies on the fact that os.close doesn't flush already buffered data -- I don't know whether os.close causes flush on Windows (it doesn't on POSIX [1]: the data shall be discarded). [1]: http://pubs.opengroup.org/onlinepubs/9699919799/functions/close.html I've uploaded a new patch with the updated tests. Please, review. ---------- Added file: http://bugs.python.org/file35129/subprocess-line-buffering-issue21332-ps3.patch _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue21332> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
