diff -r 94d0e842b9ea -r 8f0a1a4c0467 Lib/test/test_urlparse.py
--- a/Lib/test/test_urlparse.py	Fri Aug 01 12:28:49 2014 +0200
+++ b/Lib/test/test_urlparse.py	Tue Aug 05 17:38:20 2014 -0700
@@ -211,8 +211,8 @@
 
         # "abnormal" cases from RFC 1808:
         self.checkJoin(RFC1808_BASE, '', 'http://a/b/c/d;p?q#f')
-        self.checkJoin(RFC1808_BASE, '../../../g', 'http://a/../g')
-        self.checkJoin(RFC1808_BASE, '../../../../g', 'http://a/../../g')
+        self.checkJoin(RFC1808_BASE, '../../../g', 'http://a/g')
+        self.checkJoin(RFC1808_BASE, '../../../../g', 'http://a/g')
         self.checkJoin(RFC1808_BASE, '/./g', 'http://a/./g')
         self.checkJoin(RFC1808_BASE, '/../g', 'http://a/../g')
         self.checkJoin(RFC1808_BASE, 'g.', 'http://a/b/c/g.')
@@ -259,8 +259,8 @@
         self.checkJoin(RFC2396_BASE, '../../', 'http://a/')
         self.checkJoin(RFC2396_BASE, '../../g', 'http://a/g')
         self.checkJoin(RFC2396_BASE, '', RFC2396_BASE)
-        self.checkJoin(RFC2396_BASE, '../../../g', 'http://a/../g')
-        self.checkJoin(RFC2396_BASE, '../../../../g', 'http://a/../../g')
+        self.checkJoin(RFC2396_BASE, '../../../g', 'http://a/g')
+        self.checkJoin(RFC2396_BASE, '../../../../g', 'http://a/g')
         self.checkJoin(RFC2396_BASE, '/./g', 'http://a/./g')
         self.checkJoin(RFC2396_BASE, '/../g', 'http://a/../g')
         self.checkJoin(RFC2396_BASE, 'g.', 'http://a/b/c/g.')
@@ -336,6 +336,9 @@
         # Test for issue9721
         self.checkJoin('http://a/b/c/de', ';x','http://a/b/c/;x')
 
+    def test_one(self):
+        self.checkJoin(SIMPLE_BASE, '..','http://a/b/')
+
     def test_urljoins(self):
         self.checkJoin(SIMPLE_BASE, 'g:h','g:h')
         self.checkJoin(SIMPLE_BASE, 'http:g','http://a/b/c/g')
@@ -349,13 +352,14 @@
         self.checkJoin(SIMPLE_BASE, 'g?y','http://a/b/c/g?y')
         self.checkJoin(SIMPLE_BASE, 'g?y/./x','http://a/b/c/g?y/./x')
         self.checkJoin(SIMPLE_BASE, '.','http://a/b/c/')
+        self.checkJoin(SIMPLE_BASE, './.','http://a/b/c/')
         self.checkJoin(SIMPLE_BASE, './','http://a/b/c/')
         self.checkJoin(SIMPLE_BASE, '..','http://a/b/')
         self.checkJoin(SIMPLE_BASE, '../','http://a/b/')
         self.checkJoin(SIMPLE_BASE, '../g','http://a/b/g')
         self.checkJoin(SIMPLE_BASE, '../..','http://a/')
         self.checkJoin(SIMPLE_BASE, '../../g','http://a/g')
-        self.checkJoin(SIMPLE_BASE, '../../../g','http://a/../g')
+        self.checkJoin(SIMPLE_BASE, '../../../g','http://a/g')
         self.checkJoin(SIMPLE_BASE, './../g','http://a/b/g')
         self.checkJoin(SIMPLE_BASE, './g/.','http://a/b/c/g/')
         self.checkJoin(SIMPLE_BASE, '/./g','http://a/./g')
diff -r 94d0e842b9ea -r 8f0a1a4c0467 Lib/urllib/parse.py
--- a/Lib/urllib/parse.py	Fri Aug 01 12:28:49 2014 +0200
+++ b/Lib/urllib/parse.py	Tue Aug 05 17:38:20 2014 -0700
@@ -409,11 +409,13 @@
         return url
     if not url:
         return base
+
     base, url, _coerce_result = _coerce_args(base, url)
     bscheme, bnetloc, bpath, bparams, bquery, bfragment = \
             urlparse(base, '', allow_fragments)
     scheme, netloc, path, params, query, fragment = \
             urlparse(url, bscheme, allow_fragments)
+
     if scheme != bscheme or scheme not in uses_relative:
         return _coerce_result(url)
     if scheme in uses_netloc:
@@ -431,29 +433,40 @@
             query = bquery
         return _coerce_result(urlunparse((scheme, netloc, path,
                                           params, query, fragment)))
-    segments = bpath.split('/')[:-1] + path.split('/')
-    # XXX The stuff below is bogus in various ways...
-    if segments[-1] == '.':
-        segments[-1] = ''
-    while '.' in segments:
-        segments.remove('.')
-    while 1:
-        i = 1
-        n = len(segments) - 1
-        while i < n:
-            if (segments[i] == '..'
-                and segments[i-1] not in ('', '..')):
-                del segments[i-1:i+1]
-                break
-            i = i+1
-        else:
-            break
-    if segments == ['', '..']:
-        segments[-1] = ''
-    elif len(segments) >= 2 and segments[-1] == '..':
-        segments[-2:] = ['']
-    return _coerce_result(urlunparse((scheme, netloc, '/'.join(segments),
-                                      params, query, fragment)))
+
+    base_parts = bpath.split('/')
+    if base_parts[-1] != '':
+        # the last item is not a directory, so will not be taken into account
+        # in resolving the relative path 
+        del base_parts[-1]
+
+    segments = base_parts + path.split('/')
+
+    resolved_path = collections.deque()
+
+    seghandlers = {
+        '..': lambda: resolved_path.pop(),
+        '.': lambda: None,
+    }
+
+    for segment in segments:
+        try:
+            seghandlers[segment]()
+        except IndexError:
+            # no segments added yet, RFC3986 specifies that these should simply
+            # be ignored
+            pass
+        except KeyError as e:
+            resolved_path.append(segment)
+
+    if segments[-1] in ('.', '..'):
+        # do some post-processing here. if the last segment was a relative dir,
+        # then we need to append the trailing '/'
+        resolved_path.append('')
+    
+    return _coerce_result(urlunparse((scheme, netloc, '/'.join(
+        resolved_path), params, query, fragment)))
+
 
 def urldefrag(url):
     """Removes any existing fragment from URL.