From 089144e511ca4b388ce8b29ecf2965a8215ff238 Mon Sep 17 00:00:00 2001
From: Hirokazu Yamamoto <ocean-city@m2.ccsnet.ne.jp>
Date: Mon, 18 Oct 2010 13:49:09 +0000
Subject: [PATCH] Merged revisions 85689 via svnmerge from
 svn+ssh://pythondev@svn.python.org/python/branches/py3k

........
  r85689 | hirokazu.yamamoto | 2010-10-18 21:13:18 +0900 | 3 lines

  Issue #5117: Case normalization was needed on ntpath.relpath(). And
  fixed root directory issue on posixpath.relpath(). (Ported working fixes
  from ntpath)
........
---
 Lib/ntpath.py              |  4 ++--
 Lib/posixpath.py           |  4 ++--
 Lib/test/test_ntpath.py    |  1 +
 Lib/test/test_posixpath.py | 18 ++++++++++++++++++
 Misc/NEWS                  |  4 ++++
 5 files changed, 27 insertions(+), 4 deletions(-)

diff --git a/Lib/ntpath.py b/Lib/ntpath.py
index dd7372fefa..9e4cff7a6c 100644
--- a/Lib/ntpath.py
+++ b/Lib/ntpath.py
@@ -600,7 +600,7 @@ def relpath(path, start=curdir):
     path_abs = abspath(normpath(path))
     start_drive, start_rest = splitdrive(start_abs)
     path_drive, path_rest = splitdrive(path_abs)
-    if start_drive != path_drive:
+    if normcase(start_drive) != normcase(path_drive):
         error = "path is on mount '{0}', start on mount '{1}'".format(
             path_drive, start_drive)
         raise ValueError(error)
@@ -610,7 +610,7 @@ def relpath(path, start=curdir):
     # Work out how much of the filepath is shared by start and path.
     i = 0
     for e1, e2 in zip(start_list, path_list):
-        if e1 != e2:
+        if normcase(e1) != normcase(e2):
             break
         i += 1
 
diff --git a/Lib/posixpath.py b/Lib/posixpath.py
index d317cebd9b..64fe9dfc5d 100644
--- a/Lib/posixpath.py
+++ b/Lib/posixpath.py
@@ -444,8 +444,8 @@ def relpath(path, start=None):
     if start is None:
         start = curdir
 
-    start_list = abspath(start).split(sep)
-    path_list = abspath(path).split(sep)
+    start_list = [x for x in abspath(start).split(sep) if x]
+    path_list = [x for x in abspath(path).split(sep) if x]
 
     # Work out how much of the filepath is shared by start and path.
     i = len(commonprefix([start_list, path_list]))
diff --git a/Lib/test/test_ntpath.py b/Lib/test/test_ntpath.py
index 8ff7075ae5..3d18527243 100644
--- a/Lib/test/test_ntpath.py
+++ b/Lib/test/test_ntpath.py
@@ -236,6 +236,7 @@ class TestNtpath(unittest.TestCase):
         tester('ntpath.relpath("/", "/")', '.')
         tester('ntpath.relpath("/a", "/a")', '.')
         tester('ntpath.relpath("/a/b", "/a/b")', '.')
+        tester('ntpath.relpath("c:/foo", "C:/FOO")', '.')
 
 
 def test_main():
diff --git a/Lib/test/test_posixpath.py b/Lib/test/test_posixpath.py
index 0efe3ff656..6123ae2590 100644
--- a/Lib/test/test_posixpath.py
+++ b/Lib/test/test_posixpath.py
@@ -602,6 +602,15 @@ class PosixPathTest(unittest.TestCase):
                              "../"+curdir+"/a/b")
             self.assertEqual(posixpath.relpath("a", "b/c"), "../../a")
             self.assertEqual(posixpath.relpath("a", "a"), ".")
+            self.assertEqual(posixpath.relpath("/foo/bar/bat", "/x/y/z"), '../../../foo/bar/bat')
+            self.assertEqual(posixpath.relpath("/foo/bar/bat", "/foo/bar"), 'bat')
+            self.assertEqual(posixpath.relpath("/foo/bar/bat", "/"), 'foo/bar/bat')
+            self.assertEqual(posixpath.relpath("/", "/foo/bar/bat"), '../../..')
+            self.assertEqual(posixpath.relpath("/foo/bar/bat", "/x"), '../foo/bar/bat')
+            self.assertEqual(posixpath.relpath("/x", "/foo/bar/bat"), '../../../x')
+            self.assertEqual(posixpath.relpath("/", "/"), '.')
+            self.assertEqual(posixpath.relpath("/a", "/a"), '.')
+            self.assertEqual(posixpath.relpath("/a/b", "/a/b"), '.')
         finally:
             os.getcwd = real_getcwd
 
@@ -620,6 +629,15 @@ class PosixPathTest(unittest.TestCase):
                              b"../"+curdir+b"/a/b")
             self.assertEqual(posixpath.relpath(b"a", b"b/c"), b"../../a")
             self.assertEqual(posixpath.relpath(b"a", b"a"), b".")
+            self.assertEqual(posixpath.relpath(b"/foo/bar/bat", b"/x/y/z"), b'../../../foo/bar/bat')
+            self.assertEqual(posixpath.relpath(b"/foo/bar/bat", b"/foo/bar"), b'bat')
+            self.assertEqual(posixpath.relpath(b"/foo/bar/bat", b"/"), b'foo/bar/bat')
+            self.assertEqual(posixpath.relpath(b"/", b"/foo/bar/bat"), b'../../..')
+            self.assertEqual(posixpath.relpath(b"/foo/bar/bat", b"/x"), b'../foo/bar/bat')
+            self.assertEqual(posixpath.relpath(b"/x", b"/foo/bar/bat"), b'../../../x')
+            self.assertEqual(posixpath.relpath(b"/", b"/"), b'.')
+            self.assertEqual(posixpath.relpath(b"/a", b"/a"), b'.')
+            self.assertEqual(posixpath.relpath(b"/a/b", b"/a/b"), b'.')
 
             self.assertRaises(TypeError, posixpath.relpath, b"bytes", "str")
             self.assertRaises(TypeError, posixpath.relpath, "str", b"bytes")
diff --git a/Misc/NEWS b/Misc/NEWS
index 95db8ed59f..dc852eefbb 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -128,6 +128,10 @@ C-API
 Library
 -------
 
+- Issue #5117: Case normalization was needed on ntpath.relpath(). And
+  fixed root directory issue on posixpath.relpath(). (Ported working fixes
+  from ntpath)
+
 - Issue #10041: The signature of optional arguments in socket.makefile()
   didn't match that of io.open(), and they also didn't get forwarded
   properly to TextIOWrapper in text mode.  Patch by Kai Zhu.
-- 
2.40.0