Index: Lib/urllib/request.py
===================================================================
--- Lib/urllib/request.py	(revision 85346)
+++ Lib/urllib/request.py	(working copy)
@@ -1203,8 +1203,8 @@
         url = req.selector
         if url[:2] == '//' and url[2:3] != '/' and (req.host and
                 req.host != 'localhost'):
-            req.type = 'ftp'
-            return self.parent.open(req)
+            if not req.host is self.get_names():
+                raise URLError("file:// scheme allowed only on localhost")
         else:
             return self.open_local_file(req)
 
@@ -1687,7 +1687,7 @@
         if not isinstance(url, str):
             raise URLError('file error', 'proxy support for file protocol currently not implemented')
         if url[:2] == '//' and url[2:3] != '/' and url[2:12].lower() != 'localhost/':
-            return self.open_ftp(url)
+            raise ValueError("file:// scheme allowed only on localhost")
         else:
             return self.open_local_file(url)
 
Index: Lib/test/test_urllib2.py
===================================================================
--- Lib/test/test_urllib2.py	(revision 85346)
+++ Lib/test/test_urllib2.py	(working copy)
@@ -731,11 +731,11 @@
         # file:///blah.txt (a file)
         # file://ftp.example.com/blah.txt (an ftp URL)
         for url, ftp in [
-            ("file://ftp.example.com//foo.txt", True),
+            ("file://ftp.example.com//foo.txt", False),
             ("file://ftp.example.com///foo.txt", False),
 # XXXX bug: fails with OSError, should be URLError
             ("file://ftp.example.com/foo.txt", False),
-            ("file://somehost//foo/something.txt", True),
+            ("file://somehost//foo/something.txt", False),
             ("file://localhost//foo/something.txt", False),
             ]:
             req = Request(url)