issue #477: polyfill partition() use in mitogen.ssh.

mitogen/ssh.py

@@ -40,6 +40,7 @@ except ImportError:
 
 import mitogen.parent
 from mitogen.core import b
+from mitogen.core import bytes_partition
 
 
 LOG = logging.getLogger('mitogen')
@@ -98,12 +99,12 @@ def filter_debug(stream, it):
             elif state == 'in_debug':
                 if b('\n') not in buf:
                     break
-                line, _, buf = buf.partition(b('\n'))
+                line, _, buf = bytes_partition(buf, b('\n'))
                 LOG.debug('%r: %s', stream,
                           mitogen.core.to_text(line.rstrip()))
                 state = 'start_of_line'
             elif state == 'in_plain':
-                line, nl, buf = buf.partition(b('\n'))
+                line, nl, buf = bytes_partition(buf, b('\n'))
                 yield line + nl, not (nl or buf)
                 if nl:
                     state = 'start_of_line'