From 4b1e98b0af68ee80a37618ad599ead194f179cf1 Mon Sep 17 00:00:00 2001
From: Steve Dower <steve.dower@microsoft.com>
Date: Wed, 28 Dec 2016 16:02:59 -0800
Subject: [PATCH] Issue #29079: Prevent infinite loop in pathlib.resolve() on
 Windows

---
 Lib/pathlib.py | 4 +++-
 Misc/NEWS      | 2 ++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/Lib/pathlib.py b/Lib/pathlib.py
index 69653938ef7..0484dacd791 100644
--- a/Lib/pathlib.py
+++ b/Lib/pathlib.py
@@ -192,7 +192,9 @@ class _WindowsFlavour(_Flavour):
                         s = self._ext_to_normal(_getfinalpathname(s))
                     except FileNotFoundError:
                         previous_s = s
-                        s = os.path.abspath(os.path.join(s, os.pardir))
+                        s = os.path.dirname(s)
+                        if previous_s == s:
+                            return path
                     else:
                         if previous_s is None:
                             return s
diff --git a/Misc/NEWS b/Misc/NEWS
index 176b1e9e1c0..1112257a28a 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -40,6 +40,8 @@ Core and Builtins
 Library
 -------
 
+- Issue #29079: Prevent infinite loop in pathlib.resolve() on Windows
+
 - Issue #13051: Fixed recursion errors in large or resized
   curses.textpad.Textbox.  Based on patch by Tycho Andersen.