Fix #8879. Add os.link support to Windows.

Additionally, the st_ino attribute of stat structures was not being filled
in. This was left out of the fix to #10027 and was noticed due to
test_tarfile failing when applying the patch for this issue. An earlier
version of the fix to #10027 included st_ino, but that attribute got lost
in the shuffle of a few review/fix cycles. All tests pass.

Doc/library/os.rst

@@ -1058,7 +1058,10 @@ Files and Directories
 
    Create a hard link pointing to *source* named *link_name*.
 
-   Availability: Unix.
+   Availability: Unix, Windows.
+
+   .. versionchanged:: 3.2
+      Added Windows support.
 
 
 .. function:: listdir(path='.')

Lib/test/test_os.py

@@ -860,6 +860,33 @@ class TestInvalidFD(unittest.TestCase):
         if hasattr(os, "write"):
             self.check(os.write, b" ")
 
+
+class LinkTests(unittest.TestCase):
+    def setUp(self):
+        self.file1 = support.TESTFN
+        self.file2 = os.path.join(support.TESTFN + "2")
+
+        for file in (self.file1, self.file2):
+            if os.path.exists(file):
+                os.unlink(file)
+
+    tearDown = setUp
+
+    def _test_link(self, file1, file2):
+        with open(file1, "w") as f1:
+            f1.write("test")
+
+        os.link(file1, file2)
+        with open(file1, "r") as f1, open(file2, "r") as f2:
+            self.assertTrue(os.path.sameopenfile(f1.fileno(), f2.fileno()))
+
+    def test_link(self):
+        self._test_link(self.file1, self.file2)
+
+    def test_link_bytes(self):
+        self._test_link(bytes(self.file1, sys.getfilesystemencoding()),
+                        bytes(self.file2, sys.getfilesystemencoding()))
+
 if sys.platform != 'win32':
     class Win32ErrorTests(unittest.TestCase):
         pass
@@ -1221,6 +1248,7 @@ def test_main():
         FSEncodingTests,
         PidTests,
         LoginTests,
+        LinkTests,
     )
 
 if __name__ == "__main__":

Misc/NEWS

@@ -10,6 +10,8 @@ What's New in Python 3.2 Beta 1?
 Core and Builtins
 -----------------
 
+- Issue #8879. Add os.link support for Windows.
+
 - Issue #10027. st_nlink was not being set on Windows calls to os.stat or
   os.lstat. Patch by Hirokazu Yamamoto.
 

Modules/posixmodule.c

@@ -1035,6 +1035,7 @@ attribute_data_to_stat(BY_HANDLE_FILE_INFORMATION *info, struct win32_stat *resu
     FILE_TIME_to_time_t_nsec(&info->ftLastWriteTime, &result->st_mtime, &result->st_mtime_nsec);
     FILE_TIME_to_time_t_nsec(&info->ftLastAccessTime, &result->st_atime, &result->st_atime_nsec);
     result->st_nlink = info->nNumberOfLinks;
+    result->st_ino = (((__int64)info->nFileIndexHigh)<<32) + info->nFileIndexLow;
 
     return 0;
 }
@@ -2239,6 +2240,36 @@ posix_link(PyObject *self, PyObject *args)
 }
 #endif /* HAVE_LINK */
 
+#ifdef MS_WINDOWS
+PyDoc_STRVAR(win32_link__doc__,
+"link(src, dst)\n\n\
+Create a hard link to a file.");
+
+static PyObject *
+win32_link(PyObject *self, PyObject *args)
+{
+    PyObject *osrc, *odst;
+    char *src, *dst;
+    BOOL rslt;
+
+    if (!PyArg_ParseTuple(args, "O&O&:link", PyUnicode_FSConverter, &osrc,
+                          PyUnicode_FSConverter, &odst))
+        return NULL;
+
+    src = PyBytes_AsString(osrc);
+    dst = PyBytes_AsString(odst);
+
+    Py_BEGIN_ALLOW_THREADS
+    rslt = CreateHardLink(dst, src, NULL);
+    Py_END_ALLOW_THREADS
+
+    if (rslt == 0)
+        return posix_error();
+
+    Py_RETURN_NONE;
+}
+#endif /* MS_WINDOWS */
+
 
 PyDoc_STRVAR(posix_listdir__doc__,
 "listdir([path]) -> list_of_strings\n\n\
@@ -7808,6 +7839,7 @@ static PyMethodDef posix_methods[] = {
 #ifdef MS_WINDOWS
     {"startfile",       win32_startfile, METH_VARARGS, win32_startfile__doc__},
     {"kill",    win32_kill, METH_VARARGS, win32_kill__doc__},
+    {"link",    win32_link, METH_VARARGS, win32_link__doc__},
 #endif
 #ifdef HAVE_SETUID
     {"setuid",          posix_setuid, METH_VARARGS, posix_setuid__doc__},