Implement #1578269. Patch by Jason R. Coombs.

Added Windows support for os.symlink when run on Windows 6.0 or greater,
aka Vista. Previous Windows versions will raise NotImplementedError
when trying to symlink.

Includes numerous test updates and additions to test_os, including
a symlink_support module because of the fact that privilege escalation
is required in order to run the tests to ensure that the user is able
to create symlinks. By default, accounts do not have the required
privilege, so the escalation code will have to be exposed later (or
documented on how to do so). I'll be following up with that work next.

Note that the tests use ctypes, which was agreed on during the PyCon
language summit.

1 files changed, 10 insertions, 4 deletions

diff --git a/Lib/test/test_sysconfig.py b/Lib/test/test_sysconfig.py
index f4a3c8e..8314e66 100644
--- a/Lib/test/test_sysconfig.py
+++ b/Lib/test/test_sysconfig.py
@@ -12,7 +12,7 @@ import shutil
 from copy import copy, deepcopy
 
 from test.support import (run_unittest, TESTFN, unlink, get_attribute,
-                          captured_stdout)
+                          captured_stdout, skip_unless_symlink)
 
 import sysconfig
 from sysconfig import (get_paths, get_platform, get_config_vars,
@@ -239,17 +239,23 @@ class TestSysConfig(unittest.TestCase):
                   'posix_home', 'posix_prefix', 'posix_user')
         self.assertEquals(get_scheme_names(), wanted)
 
+    @skip_unless_symlink
     def test_symlink(self):
+        # On Windows, the EXE needs to know where pythonXY.dll is at so we have
+        # to add the directory to the path.
+        if sys.platform == "win32":
+            os.environ["Path"] = "{};{}".format(os.path.dirname(sys.executable),
+                                                os.environ["Path"])
+
         # Issue 7880
-        symlink = get_attribute(os, "symlink")
         def get(python):
             cmd = [python, '-c',
                    'import sysconfig; print(sysconfig.get_platform())']
-            p = subprocess.Popen(cmd, stdout=subprocess.PIPE)
+            p = subprocess.Popen(cmd, stdout=subprocess.PIPE, env=os.environ)
             return p.communicate()
         real = os.path.realpath(sys.executable)
         link = os.path.abspath(TESTFN)
-        symlink(real, link)
+        os.symlink(real, link)
         try:
             self.assertEqual(get(real), get(link))
         finally: