issue #550: fix up TTY ioctls on WSL 2016 Anniversary Update

mitogen/core.py

@@ -140,7 +140,6 @@ try:
 except NameError:
     BaseException = Exception
 
-IS_WSL = 'Microsoft' in os.uname()[2]
 PY24 = sys.version_info < (2, 5)
 PY3 = sys.version_info > (3,)
 if PY3:
@@ -164,6 +163,14 @@ try:
 except NameError:
     next = lambda it: it.next()
 
+# #550: prehistoric WSL did not advertise itself in uname output.
+try:
+    fp = open('/proc/sys/kernel/osrelease')
+    IS_WSL = 'Microsoft' in fp.read()
+    fp.close()
+except IOError:
+    IS_WSL = False
+
 
 #: Default size for calls to :meth:`Side.read` or :meth:`Side.write`, and the
 #: size of buffers configured by :func:`mitogen.parent.create_socketpair`. This

mitogen/parent.py

@@ -371,11 +371,11 @@ def create_child(args, merge_stdio=False, stderr_pipe=False, preexec_fn=None):
 
 def _acquire_controlling_tty():
     os.setsid()
-    if sys.platform == 'linux2':
+    if sys.platform in ('linux', 'linux2'):
         # On Linux, the controlling tty becomes the first tty opened by a
         # process lacking any prior tty.
         os.close(os.open(os.ttyname(2), os.O_RDWR))
-    if hasattr(termios, 'TIOCSCTTY'):
+    if hasattr(termios, 'TIOCSCTTY') and not mitogen.core.IS_WSL:
         # On BSD an explicit ioctl is required. For some inexplicable reason,
         # Python 2.6 on Travis also requires it.
         fcntl.ioctl(2, termios.TIOCSCTTY)