Update vendored windows libs

libs/win/jaraco/windows/batch.py

@@ -0,0 +1,39 @@
+import subprocess
+import itertools
+
+from more_itertools import consume, always_iterable
+
+
+def extract_environment(env_cmd, initial=None):
+    """
+    Take a command (either a single command or list of arguments)
+    and return the environment created after running that command.
+    Note that if the command must be a batch file or .cmd file, or the
+    changes to the environment will not be captured.
+
+    If initial is supplied, it is used as the initial environment passed
+    to the child process.
+    """
+    # construct the command that will alter the environment
+    env_cmd = subprocess.list2cmdline(always_iterable(env_cmd))
+    # create a tag so we can tell in the output when the proc is done
+    tag = 'Done running command'
+    # construct a cmd.exe command to do accomplish this
+    cmd = 'cmd.exe /s /c "{env_cmd} && echo "{tag}" && set"'.format(**vars())
+    # launch the process
+    proc = subprocess.Popen(cmd, stdout=subprocess.PIPE, env=initial)
+    # parse the output sent to stdout
+    lines = proc.stdout
+    # make sure the lines are strings
+
+    def make_str(s):
+        return s.decode()
+
+    lines = map(make_str, lines)
+    # consume whatever output occurs until the tag is reached
+    consume(itertools.takewhile(lambda l: tag not in l, lines))
+    # construct a dictionary of the pairs
+    result = dict(line.rstrip().split('=', 1) for line in lines)
+    # let the process finish
+    proc.communicate()
+    return result