From 383c32dd3821828f271c0bf7bcf21f0ba71792e8 Mon Sep 17 00:00:00 2001
From: Senthil Kumaran <orsenthil@gmail.com>
Date: Thu, 14 Oct 2010 11:57:35 +0000
Subject: [PATCH] Issue10063 - file:// scheme will stop accessing remote hosts
 via ftp protocol

---
 Doc/library/urllib.request.rst | 8 ++++++--
 Lib/test/test_urllib2.py       | 4 ++--
 Lib/urllib/request.py          | 6 +++---
 Misc/NEWS                      | 6 ++++++
 4 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/Doc/library/urllib.request.rst b/Doc/library/urllib.request.rst
index 21c1c2fd31c..5581f25dfd7 100644
--- a/Doc/library/urllib.request.rst
+++ b/Doc/library/urllib.request.rst
@@ -1004,8 +1004,12 @@ FileHandler Objects
 .. method:: FileHandler.file_open(req)
 
    Open the file locally, if there is no host name, or the host name is
-   ``'localhost'``. Change the protocol to ``ftp`` otherwise, and retry opening it
-   using :attr:`parent`.
+   ``'localhost'``.
+
+   This method is applicable only for local hostnames. When a remote hostname
+   is given, an :exc:`URLError` is raised.
+
+.. versionchanged:: 3.2
 
 
 .. _ftp-handler-objects:
diff --git a/Lib/test/test_urllib2.py b/Lib/test/test_urllib2.py
index 5a168ee2d80..8d59180e86f 100644
--- a/Lib/test/test_urllib2.py
+++ b/Lib/test/test_urllib2.py
@@ -731,11 +731,11 @@ class HandlerTests(unittest.TestCase):
         # 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)
diff --git a/Lib/urllib/request.py b/Lib/urllib/request.py
index e2845c9b5e6..9674b96ff1d 100644
--- a/Lib/urllib/request.py
+++ b/Lib/urllib/request.py
@@ -1228,8 +1228,8 @@ class FileHandler(BaseHandler):
         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 is supported only on localhost")
         else:
             return self.open_local_file(req)
 
@@ -1712,7 +1712,7 @@ class URLopener:
         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 is supported only on localhost")
         else:
             return self.open_local_file(url)
 
diff --git a/Misc/NEWS b/Misc/NEWS
index 4392432b21b..c8a43b5834e 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -18,6 +18,12 @@ Core and Builtins
 Library
 -------
 
+- Issue #Issue10063: file:// scheme will stop accessing remote hosts via ftp
+  protocol. file:// urls had fallback to access remote hosts via ftp. This was
+  not correct, change is made to raise a URLError when a remote host is tried
+  to access via file:// scheme.
+
+
 - Issue #1710703: Write structures for an empty ZIP archive when a ZipFile is
   created in modes 'a' or 'w' and then closed without adding any files. Raise
   BadZipfile (rather than IOError) when opening small non-ZIP files.