From ca534ab4957f3ed081133f2174543d8a560a4051 Mon Sep 17 00:00:00 2001
From: Serhiy Storchaka <storchaka@gmail.com>
Date: Sat, 27 Sep 2014 18:53:23 +0300
Subject: [PATCH] Issue #9850: Fixed macpath.join() for empty first component. 
 Patch by Oleg Oshmyan.

---
 Lib/macpath.py           |  2 +-
 Lib/test/test_macpath.py | 24 ++++++++++++++++++++++++
 Misc/NEWS                |  3 +++
 3 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/Lib/macpath.py b/Lib/macpath.py
index d34f9e944cc..5ca00977c6d 100644
--- a/Lib/macpath.py
+++ b/Lib/macpath.py
@@ -53,7 +53,7 @@ def join(s, *p):
     colon = _get_colon(s)
     path = s
     for t in p:
-        if (not s) or isabs(t):
+        if (not path) or isabs(t):
             path = t
             continue
         if t[:1] == colon:
diff --git a/Lib/test/test_macpath.py b/Lib/test/test_macpath.py
index ae4e5640fa9..22f84919bb9 100644
--- a/Lib/test/test_macpath.py
+++ b/Lib/test/test_macpath.py
@@ -49,16 +49,40 @@ class MacPathTestCase(unittest.TestCase):
     def test_join(self):
         join = macpath.join
         self.assertEqual(join('a', 'b'), ':a:b')
+        self.assertEqual(join(':a', 'b'), ':a:b')
+        self.assertEqual(join(':a:', 'b'), ':a:b')
+        self.assertEqual(join(':a::', 'b'), ':a::b')
+        self.assertEqual(join(':a', '::b'), ':a::b')
+        self.assertEqual(join('a', ':'), ':a:')
+        self.assertEqual(join('a:', ':'), 'a:')
+        self.assertEqual(join('a', ''), ':a:')
+        self.assertEqual(join('a:', ''), 'a:')
+        self.assertEqual(join('', ''), '')
         self.assertEqual(join('', 'a:b'), 'a:b')
+        self.assertEqual(join('', 'a', 'b'), ':a:b')
         self.assertEqual(join('a:b', 'c'), 'a:b:c')
         self.assertEqual(join('a:b', ':c'), 'a:b:c')
         self.assertEqual(join('a', ':b', ':c'), ':a:b:c')
+        self.assertEqual(join('a', 'b:'), 'b:')
+        self.assertEqual(join('a:', 'b:'), 'b:')
 
         self.assertEqual(join(b'a', b'b'), b':a:b')
+        self.assertEqual(join(b':a', b'b'), b':a:b')
+        self.assertEqual(join(b':a:', b'b'), b':a:b')
+        self.assertEqual(join(b':a::', b'b'), b':a::b')
+        self.assertEqual(join(b':a', b'::b'), b':a::b')
+        self.assertEqual(join(b'a', b':'), b':a:')
+        self.assertEqual(join(b'a:', b':'), b'a:')
+        self.assertEqual(join(b'a', b''), b':a:')
+        self.assertEqual(join(b'a:', b''), b'a:')
+        self.assertEqual(join(b'', b''), b'')
         self.assertEqual(join(b'', b'a:b'), b'a:b')
+        self.assertEqual(join(b'', b'a', b'b'), b':a:b')
         self.assertEqual(join(b'a:b', b'c'), b'a:b:c')
         self.assertEqual(join(b'a:b', b':c'), b'a:b:c')
         self.assertEqual(join(b'a', b':b', b':c'), b':a:b:c')
+        self.assertEqual(join(b'a', b'b:'), b'b:')
+        self.assertEqual(join(b'a:', b'b:'), b'b:')
 
     def test_splitext(self):
         splitext = macpath.splitext
diff --git a/Misc/NEWS b/Misc/NEWS
index 2f3d9d127ce..0b8ba0c1054 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -27,6 +27,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #9850: Fixed macpath.join() for empty first component.  Patch by
+  Oleg Oshmyan.
+
 - Issue #22427: TemporaryDirectory no longer attempts to clean up twice when
   used in the with statement in generator.