Correction to f1509fc75435 - Issue #11583

Rather than wrapping the C _isdir function in a Python function,
just import the C _isdir function directly. Additionally, add in the
docstring which was left out.

Lib/ntpath.py

@@ -527,9 +527,7 @@ try:
     # attribute to tell whether or not the path is a directory.
     # This is overkill on Windows - just pass the path to GetFileAttributes
     # and check the attribute from there.
-    from nt import _isdir
+    from nt import _isdir as isdir
 except ImportError:
-    from genericpath import isdir as _isdir
-
-def isdir(path):
-    return _isdir(path)
+    # Use genericpath.isdir as imported above.
+    pass

Modules/posixmodule.c

@@ -4200,6 +4200,9 @@ win32_kill(PyObject *self, PyObject *args)
     return result;
 }
 
+PyDoc_STRVAR(posix__isdir__doc__,
+"Return true if the pathname refers to an existing directory.");
+
 static PyObject *
 posix__isdir(PyObject *self, PyObject *args)
 {
@@ -9003,7 +9006,7 @@ static PyMethodDef posix_methods[] = {
     {"abort",           posix_abort, METH_NOARGS, posix_abort__doc__},
 #ifdef MS_WINDOWS
     {"_getfullpathname",        posix__getfullpathname, METH_VARARGS, NULL},
-    {"_isdir",                  posix__isdir, METH_VARARGS, NULL},
+    {"_isdir",                  posix__isdir, METH_VARARGS, posix__isdir__doc__},
 #endif
 #ifdef HAVE_GETLOADAVG
     {"getloadavg",      posix_getloadavg, METH_NOARGS, posix_getloadavg__doc__},