on windows, if launched from cmd, subprocess calls fail

[dfberger]

if you launch sublime from a command prompt, python subprocess calls fail thusly:

Exception in thread Thread-3:
Traceback (most recent call last):
File ".\threading.py", line 532, in bootstrap_inner
File ".\Perforce.py", line 688, in run
File ".\Perforce.py", line 665, in MakeCheckedOutFileList
File ".\Perforce.py", line 639, in MakeFileListFromChangelist
File ".\Perforce.py", line 91, in GetUserFromClientspec
File ".\subprocess.py", line 626, in __init
File ".\subprocess.py", line 734, in _get_handles
File ".\subprocess.py", line 773, in _make_inheritable
WindowsError: [Error 6] The handle is invalid

it looks like a python/windows interop issue that you get a handle from cmd that suprocess tries to duphandle and fails.

if you provide pipes (or devnull) for all three of stdin/stdout/stderr, this should go away.