From 3f4a2cb00b03896fa7d99213f007fe9ae9aeaea4 Mon Sep 17 00:00:00 2001
From: Safia Abdalla
 <captainsafia@dhcp-10-105-108-105.wireless.northwestern.private>
Date: Thu, 25 Feb 2016 01:34:14 -0600
Subject: [PATCH 1/3] Add same_file utility function

---
 notebook/utils.py | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/notebook/utils.py b/notebook/utils.py
index 92a2410cc..c472367b2 100644
--- a/notebook/utils.py
+++ b/notebook/utils.py
@@ -141,6 +141,23 @@ def is_hidden(abs_path, abs_root=''):
 
     return False
 
+def same_file(path, other_path):
+    """
+    Check if path and other_path are hard links to the same file. This is a
+    utility implementation of Python's os.path.samefile which is not available
+    with Python 2.x and Windows.
+
+    Parameters
+    -----------
+    path:       String representing a path to a file
+    other_path: String representing a path to another file
+
+    Returns
+    -----------
+    same:   Boolean that is True if both path and other path are the same
+    """
+    return os.stat(path).st_ino == os.stat(other_path).st_ino
+
 def to_os_path(path, root=''):
     """Convert an API path to a filesystem path
     

From 7a8aa92b73bc647ea4fefa85932fe02e9435e69e Mon Sep 17 00:00:00 2001
From: Safia Abdalla <safia@safia.rocks>
Date: Thu, 25 Feb 2016 01:36:34 -0600
Subject: [PATCH 2/3] Add same_file check in rename_file

---
 notebook/services/contents/filemanager.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/notebook/services/contents/filemanager.py b/notebook/services/contents/filemanager.py
index d82bba403..34a342462 100644
--- a/notebook/services/contents/filemanager.py
+++ b/notebook/services/contents/filemanager.py
@@ -25,6 +25,7 @@ from . import tz
 from notebook.utils import (
     is_hidden,
     to_api_path,
+    same_file,
 )
 
 _script_exporter = None
@@ -460,7 +461,7 @@ class FileContentsManager(FileManagerMixin, ContentsManager):
         old_os_path = self._get_os_path(old_path)
 
         # Should we proceed with the move?
-        if os.path.exists(new_os_path):
+        if os.path.exists(new_os_path) and not same_file(old_os_path, new_os_path):
             raise web.HTTPError(409, u'File already exists: %s' % new_path)
 
         # Move the file

From e30c28eeba5ac1ee18eb6027bfb67c91afaf2f51 Mon Sep 17 00:00:00 2001
From: Safia Abdalla <safia@safia.rocks>
Date: Thu, 25 Feb 2016 02:06:15 -0600
Subject: [PATCH 3/3] Updated same_file to check for same device

---
 notebook/utils.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/notebook/utils.py b/notebook/utils.py
index c472367b2..fa083b029 100644
--- a/notebook/utils.py
+++ b/notebook/utils.py
@@ -156,7 +156,10 @@ def same_file(path, other_path):
     -----------
     same:   Boolean that is True if both path and other path are the same
     """
-    return os.stat(path).st_ino == os.stat(other_path).st_ino
+    path_stat = os.stat(path)
+    other_path_stat = os.stat(other_path)
+    return (path_stat.st_ino == other_path_stat.st_ino and 
+            path_stat.st_dev == other_path_stat.st_dev)
 
 def to_os_path(path, root=''):
     """Convert an API path to a filesystem path