diff --git a/Lib/test/test_os.py b/Lib/test/test_os.py index e40f763af15..35aa7fa75ed 100644 --- a/Lib/test/test_os.py +++ b/Lib/test/test_os.py @@ -97,6 +97,25 @@ class FileTests(unittest.TestCase): self.assertEqual(fobj.read().splitlines(), [b"bacon", b"eggs", b"spam"]) + def write_windows_console(self, *args): + retcode = subprocess.call(args, + # use a new console to not flood the test output + creationflags=subprocess.CREATE_NEW_CONSOLE, + # use a shell to hide the console window (SW_HIDE) + shell=True) + self.assertEqual(retcode, 0) + + @unittest.skipUnless(sys.platform == 'win32', + 'test specific to the Windows console') + def test_write_windows_console(self): + # Issue #11395: the Windows console returns an error (12: not enough + # space error) on writing into stdout if stdout mode is binary and the + # length is greater than 66,000 bytes (or less, depending on heap + # usage). + code = "print('x' * 100000)" + self.write_windows_console(sys.executable, "-c", code) + self.write_windows_console(sys.executable, "-u", "-c", code) + class TemporaryFileTests(unittest.TestCase): def setUp(self): diff --git a/Misc/NEWS b/Misc/NEWS index 310132783f1..d55c88869ff 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -10,6 +10,12 @@ What's New in Python 3.3 Alpha 1? Core and Builtins ----------------- +- Issue #11395: io.FileIO().write() clamps the data length to 32,767 bytes on + Windows if the file is a TTY to workaround a Windows bug. The Windows console + returns an error (12: not enough space error) on writing into stdout if + stdout mode is binary and the length is greater than 66,000 bytes (or less, + depending on heap usage). + - Issue #11320: fix bogus memory management in Modules/getpath.c, leading to a possible crash when calling Py_SetPath(). diff --git a/Modules/_io/fileio.c b/Modules/_io/fileio.c index f96f2e2ede2..1aa5ee992d7 100644 --- a/Modules/_io/fileio.c +++ b/Modules/_io/fileio.c @@ -712,7 +712,14 @@ fileio_write(fileio *self, PyObject *args) errno = 0; len = pbuf.len; #if defined(MS_WIN64) || defined(MS_WINDOWS) - if (len > INT_MAX) + if (len > 32767 && isatty(self->fd)) { + /* Issue #11395: the Windows console returns an error (12: not + enough space error) on writing into stdout if stdout mode is + binary and the length is greater than 66,000 bytes (or less, + depending on heap usage). */ + len = 32767; + } + else if (len > INT_MAX) len = INT_MAX; n = write(self->fd, pbuf.buf, (int)len); #else