2018 backport: modules.cmdmod: handle windows environ better

python exposes an nt.environ for case insensitive environment behavior
that is native to windows; so it makes sense to use this instead of
os.environ to avoid enexpected behavior and failure.

further detail: https://bugs.python.org/issue28824

salt/modules/cmdmod.py

@@ -539,7 +539,11 @@ def _run(cmd,
         run_env = env
 
     else:
-        run_env = os.environ.copy()
+        if salt.utils.platform.is_windows():
+            import nt
+            run_env = nt.environ.copy()
+        else:
+            run_env = os.environ.copy()
         run_env.update(env)
 
     if prepend_path:
@@ -3033,7 +3037,12 @@ def shell_info(shell, list_modules=False):
         # salt-call will general have home set, the salt-minion service may not
         # We need to assume ports of unix shells to windows will look after
         # themselves in setting HOME as they do it in many different ways
-        newenv = os.environ
+        if salt.utils.platform.is_windows():
+            import nt
+            newenv = nt.environ
+        else:
+            newenv = os.environ
+
         if ('HOME' not in newenv) and (not salt.utils.platform.is_windows()):
             newenv['HOME'] = os.path.expanduser('~')
             log.debug('HOME environment set to %s', newenv['HOME'])

tests/integration/modules/test_cmdmod.py

@@ -380,3 +380,12 @@ class CMDModuleTest(ModuleCase):
             self.assertIn('administrator', cmd)
         else:
             self.assertEqual('root', cmd)
+
+    @skipIf(not salt.utils.platform.is_windows(), 'minion is not windows')
+    def test_windows_env_handling(self):
+        '''
+        Ensure that nt.environ is used properly with cmd.run*
+        '''
+        out = self.run_function('cmd.run', ['set'], env={"abc": "123", "ABC": "456"}).splitlines()
+        self.assertIn('abc=123', out)
+        self.assertIn('ABC=456', out)