From 0630a2dfaa97591b11b897863824fa111c5ff172 Mon Sep 17 00:00:00 2001
From: barneygale <barney.gale@gmail.com>
Date: Wed, 16 Apr 2025 19:50:19 +0100
Subject: [PATCH 1/9] GH-123599: `url2pathname()`: don't call `gethostbyname()`
 by default

Follow-up to 0879ebc.

Add *resolve_netloc* keyword-only argument to `url2pathname()`, defaulting
to false. When set to true, we call `socket.gethostbyname()` to resolve
the URL authority (netloc).
---
 Doc/library/pathlib.rst                       |  8 ++++----
 Doc/library/urllib.request.rst                | 20 +++++++++++++------
 Doc/whatsnew/3.14.rst                         |  8 +++++---
 Lib/test/test_pathlib/test_pathlib.py         |  1 -
 Lib/test/test_urllib.py                       | 15 ++++++++++----
 Lib/urllib/request.py                         | 15 +++++++++-----
 ...-11-14-21-17-48.gh-issue-126838.Yr5vKF.rst |  9 +++++----
 7 files changed, 49 insertions(+), 27 deletions(-)

diff --git a/Doc/library/pathlib.rst b/Doc/library/pathlib.rst
index b82986902861b2..4fb8709261612a 100644
--- a/Doc/library/pathlib.rst
+++ b/Doc/library/pathlib.rst
@@ -872,10 +872,10 @@ conforming to :rfc:`8089`.
    .. versionadded:: 3.13
 
    .. versionchanged:: next
-      If a URL authority (e.g. a hostname) is present and resolves to a local
-      address, it is discarded. If an authority is present and *doesn't*
-      resolve to a local address, then on Windows a UNC path is returned (as
-      before), and on other platforms a :exc:`ValueError` is raised.
+      If a URL authority matches the current hostname, it is discarded.
+      Otherwise, if the authority isn't empty or ``localhost``, then on
+      Windows a UNC path is returned (as before), and on other platforms a
+      :exc:`ValueError` is raised.
 
 
 .. method:: Path.as_uri()
diff --git a/Doc/library/urllib.request.rst b/Doc/library/urllib.request.rst
index b7c0c7d5099806..b471ce49a1be6a 100644
--- a/Doc/library/urllib.request.rst
+++ b/Doc/library/urllib.request.rst
@@ -175,7 +175,7 @@ The :mod:`urllib.request` module defines the following functions:
       The *add_scheme* argument was added.
 
 
-.. function:: url2pathname(url, *, require_scheme=False)
+.. function:: url2pathname(url, *, require_scheme=False, resolve_netloc=False)
 
    Convert the given ``file:`` URL to a local path. This function uses
    :func:`~urllib.parse.unquote` to decode the URL.
@@ -185,6 +185,13 @@ The :mod:`urllib.request` module defines the following functions:
    value should include the prefix; a :exc:`~urllib.error.URLError` is raised
    if it doesn't.
 
+   The URL authority is discarded if it empty, ``localhost``, or the current
+   hostname. Otherwise, if *resolve_netloc* is set to true, the authority is
+   resolved to an IP address using :func:`socket.gethostbyname`, and discarded
+   if it matches a local IP. If the authority is still unhandled, then on
+   Windows a UNC path is returned, and on other platforms a
+   :exc:`~urllib.error.URLError` is raised.
+
    This example shows the function being used on Windows::
 
       >>> from urllib.request import url2pathname
@@ -198,15 +205,16 @@ The :mod:`urllib.request` module defines the following functions:
       :exc:`OSError` exception to be raised on Windows.
 
    .. versionchanged:: next
-      This function calls :func:`socket.gethostbyname` if the URL authority
-      isn't empty, ``localhost``, or the machine hostname. If the authority
-      resolves to a local IP address then it is discarded; otherwise, on
-      Windows a UNC path is returned (as before), and on other platforms a
-      :exc:`~urllib.error.URLError` is raised.
+      The URL authority is discarded if it matches the machine hostname.
+      Otherwise, on Windows a UNC path is returned (as before), and on other
+      platforms a :exc:`~urllib.error.URLError` is raised.
 
    .. versionchanged:: next
       The *require_scheme* argument was added.
 
+   .. versionchanged:: next
+      The *resolve_netloc* argument was added.
+
 
 .. function:: getproxies()
 
diff --git a/Doc/whatsnew/3.14.rst b/Doc/whatsnew/3.14.rst
index c50d1669fef84c..4d5b6717f3c416 100644
--- a/Doc/whatsnew/3.14.rst
+++ b/Doc/whatsnew/3.14.rst
@@ -1230,9 +1230,11 @@ urllib
 
   - Accept a complete URL when the new *require_scheme* argument is set to
     true.
-  - Discard URL authorities that resolve to a local IP address.
-  - Raise :exc:`~urllib.error.URLError` if a URL authority doesn't resolve
-    to a local IP address, except on Windows where we return a UNC path.
+  - Discard URL authority if it matches the current hostname.
+  - Discard URL authority if it resolves to a local IP address when the new
+    *resolve_netloc* argument is set to true.
+  - Raise :exc:`~urllib.error.URLError` if a URL authority isn't local,
+    except on Windows where we return a UNC path as before.
 
   In :func:`urllib.request.pathname2url`:
 
diff --git a/Lib/test/test_pathlib/test_pathlib.py b/Lib/test/test_pathlib/test_pathlib.py
index 41a79d0dceb0eb..e23dac3c25fa35 100644
--- a/Lib/test/test_pathlib/test_pathlib.py
+++ b/Lib/test/test_pathlib/test_pathlib.py
@@ -3290,7 +3290,6 @@ def test_from_uri_posix(self):
         self.assertEqual(P.from_uri('file:////foo/bar'), P('//foo/bar'))
         self.assertEqual(P.from_uri('file://localhost/foo/bar'), P('/foo/bar'))
         if not is_wasi:
-            self.assertEqual(P.from_uri('file://127.0.0.1/foo/bar'), P('/foo/bar'))
             self.assertEqual(P.from_uri(f'file://{socket.gethostname()}/foo/bar'),
                              P('/foo/bar'))
         self.assertRaises(ValueError, P.from_uri, 'foo/bar')
diff --git a/Lib/test/test_urllib.py b/Lib/test/test_urllib.py
index 90de828cc71249..2720cbabd21e44 100644
--- a/Lib/test/test_urllib.py
+++ b/Lib/test/test_urllib.py
@@ -1551,7 +1551,8 @@ def test_url2pathname_require_scheme(self):
                     urllib.request.url2pathname(url, require_scheme=True),
                     expected_path)
 
-        error_subtests = [
+    def test_url2pathname_require_scheme_errors(self):
+        subtests = [
             '',
             ':',
             'foo',
@@ -1561,13 +1562,21 @@ def test_url2pathname_require_scheme(self):
             'data:file:foo',
             'data:file://foo',
         ]
-        for url in error_subtests:
+        for url in subtests:
             with self.subTest(url=url):
                 self.assertRaises(
                     urllib.error.URLError,
                     urllib.request.url2pathname,
                     url, require_scheme=True)
 
+    def test_url2pathname_resolve_netloc(self):
+        fn = urllib.request.url2pathname
+        sep = os.path.sep
+        self.assertRaises(urllib.error.URLError, fn, '//127.0.0.1/foo/bar')
+        self.assertEqual(fn('//127.0.0.1/foo/bar', resolve_netloc=True), f'{sep}foo{sep}bar')
+        self.assertEqual(fn(f'//{socket.gethostname()}/foo/bar'), f'{sep}foo{sep}bar')
+        self.assertEqual(fn(f'//{socket.gethostname()}/foo/bar', resolve_netloc=True), f'{sep}foo{sep}bar')
+
     @unittest.skipUnless(sys.platform == 'win32',
                          'test specific to Windows pathnames.')
     def test_url2pathname_win(self):
@@ -1622,8 +1631,6 @@ def test_url2pathname_posix(self):
         self.assertRaises(urllib.error.URLError, fn, '//:80/foo/bar')
         self.assertRaises(urllib.error.URLError, fn, '//:/foo/bar')
         self.assertRaises(urllib.error.URLError, fn, '//c:80/foo/bar')
-        self.assertEqual(fn('//127.0.0.1/foo/bar'), '/foo/bar')
-        self.assertEqual(fn(f'//{socket.gethostname()}/foo/bar'), '/foo/bar')
 
     @unittest.skipUnless(os_helper.FS_NONASCII, 'need os_helper.FS_NONASCII')
     def test_url2pathname_nonascii(self):
diff --git a/Lib/urllib/request.py b/Lib/urllib/request.py
index 9a6b29a90a2968..2f9505527bb08a 100644
--- a/Lib/urllib/request.py
+++ b/Lib/urllib/request.py
@@ -1466,7 +1466,7 @@ def get_names(self):
     def open_local_file(self, req):
         import email.utils
         import mimetypes
-        localfile = url2pathname(req.full_url, require_scheme=True)
+        localfile = url2pathname(req.full_url, require_scheme=True, resolve_netloc=True)
         try:
             stats = os.stat(localfile)
             size = stats.st_size
@@ -1482,7 +1482,7 @@ def open_local_file(self, req):
 
     file_open = open_local_file
 
-def _is_local_authority(authority):
+def _is_local_authority(authority, resolve):
     # Compare hostnames
     if not authority or authority == 'localhost':
         return True
@@ -1494,6 +1494,8 @@ def _is_local_authority(authority):
         if authority == hostname:
             return True
     # Compare IP addresses
+    if not resolve:
+        return False
     try:
         address = socket.gethostbyname(authority)
     except (socket.gaierror, AttributeError):
@@ -1643,11 +1645,14 @@ def data_open(self, req):
 
 # Code move from the old urllib module
 
-def url2pathname(url, *, require_scheme=False):
+def url2pathname(url, *, require_scheme=False, resolve_netloc=False):
     """Convert the given file URL to a local file system path.
 
     The 'file:' scheme prefix must be omitted unless *require_scheme*
     is set to true.
+
+    The URL authority may be resolved with gethostbyname() if
+    *resolve_netloc* is set to true.
     """
     if require_scheme:
         scheme, url = _splittype(url)
@@ -1655,7 +1660,7 @@ def url2pathname(url, *, require_scheme=False):
             raise URLError("URL is missing a 'file:' scheme")
     authority, url = _splithost(url)
     if os.name == 'nt':
-        if not _is_local_authority(authority):
+        if not _is_local_authority(authority, resolve_netloc):
             # e.g. file://server/share/file.txt
             url = '//' + authority + url
         elif url[:3] == '///':
@@ -1669,7 +1674,7 @@ def url2pathname(url, *, require_scheme=False):
                 # Older URLs use a pipe after a drive letter
                 url = url[:1] + ':' + url[2:]
         url = url.replace('/', '\\')
-    elif not _is_local_authority(authority):
+    elif not _is_local_authority(authority, resolve_netloc):
         raise URLError("file:// scheme is supported only on localhost")
     encoding = sys.getfilesystemencoding()
     errors = sys.getfilesystemencodeerrors()
diff --git a/Misc/NEWS.d/next/Library/2024-11-14-21-17-48.gh-issue-126838.Yr5vKF.rst b/Misc/NEWS.d/next/Library/2024-11-14-21-17-48.gh-issue-126838.Yr5vKF.rst
index 857cc359229daa..b13011f8927053 100644
--- a/Misc/NEWS.d/next/Library/2024-11-14-21-17-48.gh-issue-126838.Yr5vKF.rst
+++ b/Misc/NEWS.d/next/Library/2024-11-14-21-17-48.gh-issue-126838.Yr5vKF.rst
@@ -1,5 +1,6 @@
 Fix issue where :func:`urllib.request.url2pathname` mishandled file URLs with
-authorities. If an authority is present and resolves to ``localhost``, it is
-now discarded. If an authority is present but *doesn't* resolve to
-``localhost``, then on Windows a UNC path is returned (as before), and on
-other platforms a :exc:`urllib.error.URLError` is now raised.
+authorities. If an authority matches the current hostname it is now discarded.
+Otherwise, if the new *resolve_netloc* keyword-only argument is set to true,
+the authority is resolved and discarded if it matches a local IP address. If
+the authority is still unhandled, then then on Windows a UNC path is returned
+(as before), and on other platforms a :exc:`urllib.error.URLError` is now raised.

From 26c8688a9f971379151ef228a28ae66bb2f754c7 Mon Sep 17 00:00:00 2001
From: barneygale <barney.gale@gmail.com>
Date: Wed, 16 Apr 2025 20:25:55 +0100
Subject: [PATCH 2/9] Docs + tests fixes

---
 Doc/library/pathlib.rst        | 7 +++----
 Doc/library/urllib.request.rst | 6 +++---
 Lib/test/test_urllib.py        | 3 ++-
 3 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/Doc/library/pathlib.rst b/Doc/library/pathlib.rst
index 4fb8709261612a..a7864bd2e23ec6 100644
--- a/Doc/library/pathlib.rst
+++ b/Doc/library/pathlib.rst
@@ -872,10 +872,9 @@ conforming to :rfc:`8089`.
    .. versionadded:: 3.13
 
    .. versionchanged:: next
-      If a URL authority matches the current hostname, it is discarded.
-      Otherwise, if the authority isn't empty or ``localhost``, then on
-      Windows a UNC path is returned (as before), and on other platforms a
-      :exc:`ValueError` is raised.
+      The URL authority is discarded if it matches the machine hostname.
+      Otherwise, on Windows a UNC path is returned (as before), and on other
+      platforms a :exc:`ValueError` is raised.
 
 
 .. method:: Path.as_uri()
diff --git a/Doc/library/urllib.request.rst b/Doc/library/urllib.request.rst
index b471ce49a1be6a..dc0e5fb442884b 100644
--- a/Doc/library/urllib.request.rst
+++ b/Doc/library/urllib.request.rst
@@ -187,9 +187,9 @@ The :mod:`urllib.request` module defines the following functions:
 
    The URL authority is discarded if it empty, ``localhost``, or the current
    hostname. Otherwise, if *resolve_netloc* is set to true, the authority is
-   resolved to an IP address using :func:`socket.gethostbyname`, and discarded
-   if it matches a local IP. If the authority is still unhandled, then on
-   Windows a UNC path is returned, and on other platforms a
+   resolved using :func:`socket.gethostbyname`, and discarded if it matches a
+   local IP address. If the authority is still unhandled, then on Windows a
+   UNC path is returned, and on other platforms a
    :exc:`~urllib.error.URLError` is raised.
 
    This example shows the function being used on Windows::
diff --git a/Lib/test/test_urllib.py b/Lib/test/test_urllib.py
index 2720cbabd21e44..00a20f92c199f2 100644
--- a/Lib/test/test_urllib.py
+++ b/Lib/test/test_urllib.py
@@ -1572,7 +1572,6 @@ def test_url2pathname_require_scheme_errors(self):
     def test_url2pathname_resolve_netloc(self):
         fn = urllib.request.url2pathname
         sep = os.path.sep
-        self.assertRaises(urllib.error.URLError, fn, '//127.0.0.1/foo/bar')
         self.assertEqual(fn('//127.0.0.1/foo/bar', resolve_netloc=True), f'{sep}foo{sep}bar')
         self.assertEqual(fn(f'//{socket.gethostname()}/foo/bar'), f'{sep}foo{sep}bar')
         self.assertEqual(fn(f'//{socket.gethostname()}/foo/bar', resolve_netloc=True), f'{sep}foo{sep}bar')
@@ -1607,6 +1606,7 @@ def test_url2pathname_win(self):
         self.assertEqual(fn('//server/path/to/file'), '\\\\server\\path\\to\\file')
         self.assertEqual(fn('////server/path/to/file'), '\\\\server\\path\\to\\file')
         self.assertEqual(fn('/////server/path/to/file'), '\\\\server\\path\\to\\file')
+        self.assertEqual(fn('//127.0.0.1/path/to/file'), '\\\\127.0.0.1\\path\\to\\file')
         # Localhost paths
         self.assertEqual(fn('//localhost/C:/path/to/file'), 'C:\\path\\to\\file')
         self.assertEqual(fn('//localhost/C|/path/to/file'), 'C:\\path\\to\\file')
@@ -1631,6 +1631,7 @@ def test_url2pathname_posix(self):
         self.assertRaises(urllib.error.URLError, fn, '//:80/foo/bar')
         self.assertRaises(urllib.error.URLError, fn, '//:/foo/bar')
         self.assertRaises(urllib.error.URLError, fn, '//c:80/foo/bar')
+        self.assertRaises(urllib.error.URLError, fn, '//127.0.0.1/foo/bar')
 
     @unittest.skipUnless(os_helper.FS_NONASCII, 'need os_helper.FS_NONASCII')
     def test_url2pathname_nonascii(self):

From 1bff8b944a74a755b47cdbf3c2f9248200515044 Mon Sep 17 00:00:00 2001
From: barneygale <barney.gale@gmail.com>
Date: Wed, 16 Apr 2025 20:55:27 +0100
Subject: [PATCH 3/9] This is hard to explain D:

---
 Doc/library/pathlib.rst                             |  5 +++--
 Doc/library/urllib.request.rst                      |  5 +++--
 .../2024-11-14-21-17-48.gh-issue-126838.Yr5vKF.rst  | 13 ++++++++-----
 3 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/Doc/library/pathlib.rst b/Doc/library/pathlib.rst
index a7864bd2e23ec6..04175ea028e310 100644
--- a/Doc/library/pathlib.rst
+++ b/Doc/library/pathlib.rst
@@ -873,8 +873,9 @@ conforming to :rfc:`8089`.
 
    .. versionchanged:: next
       The URL authority is discarded if it matches the machine hostname.
-      Otherwise, on Windows a UNC path is returned (as before), and on other
-      platforms a :exc:`ValueError` is raised.
+      Otherwise, if the authority isn't empty or ``localhost``, then on
+      Windows a UNC path is returned (as before), and on other platforms a
+      :exc:`ValueError` is raised.
 
 
 .. method:: Path.as_uri()
diff --git a/Doc/library/urllib.request.rst b/Doc/library/urllib.request.rst
index dc0e5fb442884b..6580661fa4c5d3 100644
--- a/Doc/library/urllib.request.rst
+++ b/Doc/library/urllib.request.rst
@@ -206,8 +206,9 @@ The :mod:`urllib.request` module defines the following functions:
 
    .. versionchanged:: next
       The URL authority is discarded if it matches the machine hostname.
-      Otherwise, on Windows a UNC path is returned (as before), and on other
-      platforms a :exc:`~urllib.error.URLError` is raised.
+      Otherwise, if the authority isn't empty or ``localhost``, then on
+      Windows a UNC path is returned (as before), and on other platforms a
+      :exc:`~urllib.error.URLError` is raised.
 
    .. versionchanged:: next
       The *require_scheme* argument was added.
diff --git a/Misc/NEWS.d/next/Library/2024-11-14-21-17-48.gh-issue-126838.Yr5vKF.rst b/Misc/NEWS.d/next/Library/2024-11-14-21-17-48.gh-issue-126838.Yr5vKF.rst
index b13011f8927053..61282f4ac8fce0 100644
--- a/Misc/NEWS.d/next/Library/2024-11-14-21-17-48.gh-issue-126838.Yr5vKF.rst
+++ b/Misc/NEWS.d/next/Library/2024-11-14-21-17-48.gh-issue-126838.Yr5vKF.rst
@@ -1,6 +1,9 @@
 Fix issue where :func:`urllib.request.url2pathname` mishandled file URLs with
-authorities. If an authority matches the current hostname it is now discarded.
-Otherwise, if the new *resolve_netloc* keyword-only argument is set to true,
-the authority is resolved and discarded if it matches a local IP address. If
-the authority is still unhandled, then then on Windows a UNC path is returned
-(as before), and on other platforms a :exc:`urllib.error.URLError` is now raised.
+authorities. The process now works as follows:
+
+1. Discard authority if it is empty or ``localhost``; otherwise
+2. (New) Discard authority if it matches the current hostname; otherwise
+3. (New) If the new *resolve_netloc* keyword-only argument is set to true,
+   discard authority if it resolves to a local IP address; otherwise
+4. On Windows, return a UNC path; otherwise
+5. (New) Raise :exc:`urllib.error.URLError`.

From 4ec391f0e75fad24a58fd74972bd9a61d51aeaa8 Mon Sep 17 00:00:00 2001
From: barneygale <barney.gale@gmail.com>
Date: Wed, 16 Apr 2025 21:04:16 +0100
Subject: [PATCH 4/9] Terminology

---
 Doc/library/pathlib.rst                                       | 2 +-
 Doc/library/urllib.request.rst                                | 4 ++--
 .../Library/2024-11-14-21-17-48.gh-issue-126838.Yr5vKF.rst    | 2 +-
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/Doc/library/pathlib.rst b/Doc/library/pathlib.rst
index 04175ea028e310..acb91812818dab 100644
--- a/Doc/library/pathlib.rst
+++ b/Doc/library/pathlib.rst
@@ -872,7 +872,7 @@ conforming to :rfc:`8089`.
    .. versionadded:: 3.13
 
    .. versionchanged:: next
-      The URL authority is discarded if it matches the machine hostname.
+      The URL authority is discarded if it matches the local hostname.
       Otherwise, if the authority isn't empty or ``localhost``, then on
       Windows a UNC path is returned (as before), and on other platforms a
       :exc:`ValueError` is raised.
diff --git a/Doc/library/urllib.request.rst b/Doc/library/urllib.request.rst
index 6580661fa4c5d3..46dc7a204815c0 100644
--- a/Doc/library/urllib.request.rst
+++ b/Doc/library/urllib.request.rst
@@ -185,7 +185,7 @@ The :mod:`urllib.request` module defines the following functions:
    value should include the prefix; a :exc:`~urllib.error.URLError` is raised
    if it doesn't.
 
-   The URL authority is discarded if it empty, ``localhost``, or the current
+   The URL authority is discarded if it empty, ``localhost``, or the local
    hostname. Otherwise, if *resolve_netloc* is set to true, the authority is
    resolved using :func:`socket.gethostbyname`, and discarded if it matches a
    local IP address. If the authority is still unhandled, then on Windows a
@@ -205,7 +205,7 @@ The :mod:`urllib.request` module defines the following functions:
       :exc:`OSError` exception to be raised on Windows.
 
    .. versionchanged:: next
-      The URL authority is discarded if it matches the machine hostname.
+      The URL authority is discarded if it matches the local hostname.
       Otherwise, if the authority isn't empty or ``localhost``, then on
       Windows a UNC path is returned (as before), and on other platforms a
       :exc:`~urllib.error.URLError` is raised.
diff --git a/Misc/NEWS.d/next/Library/2024-11-14-21-17-48.gh-issue-126838.Yr5vKF.rst b/Misc/NEWS.d/next/Library/2024-11-14-21-17-48.gh-issue-126838.Yr5vKF.rst
index 61282f4ac8fce0..9b24fa2f4afe49 100644
--- a/Misc/NEWS.d/next/Library/2024-11-14-21-17-48.gh-issue-126838.Yr5vKF.rst
+++ b/Misc/NEWS.d/next/Library/2024-11-14-21-17-48.gh-issue-126838.Yr5vKF.rst
@@ -2,7 +2,7 @@ Fix issue where :func:`urllib.request.url2pathname` mishandled file URLs with
 authorities. The process now works as follows:
 
 1. Discard authority if it is empty or ``localhost``; otherwise
-2. (New) Discard authority if it matches the current hostname; otherwise
+2. (New) Discard authority if it matches the local hostname; otherwise
 3. (New) If the new *resolve_netloc* keyword-only argument is set to true,
    discard authority if it resolves to a local IP address; otherwise
 4. On Windows, return a UNC path; otherwise

From 8df17b414f1e49e1955714b5e8bc95b783c4c816 Mon Sep 17 00:00:00 2001
From: barneygale <barney.gale@gmail.com>
Date: Wed, 16 Apr 2025 21:06:44 +0100
Subject: [PATCH 5/9] Faffing

---
 Doc/library/urllib.request.rst | 2 +-
 Doc/whatsnew/3.14.rst          | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/Doc/library/urllib.request.rst b/Doc/library/urllib.request.rst
index 46dc7a204815c0..8bd2e6833f354e 100644
--- a/Doc/library/urllib.request.rst
+++ b/Doc/library/urllib.request.rst
@@ -187,7 +187,7 @@ The :mod:`urllib.request` module defines the following functions:
 
    The URL authority is discarded if it empty, ``localhost``, or the local
    hostname. Otherwise, if *resolve_netloc* is set to true, the authority is
-   resolved using :func:`socket.gethostbyname`, and discarded if it matches a
+   resolved using :func:`socket.gethostbyname` and discarded if it matches a
    local IP address. If the authority is still unhandled, then on Windows a
    UNC path is returned, and on other platforms a
    :exc:`~urllib.error.URLError` is raised.
diff --git a/Doc/whatsnew/3.14.rst b/Doc/whatsnew/3.14.rst
index 4d5b6717f3c416..d2d4bad82894a0 100644
--- a/Doc/whatsnew/3.14.rst
+++ b/Doc/whatsnew/3.14.rst
@@ -1230,7 +1230,7 @@ urllib
 
   - Accept a complete URL when the new *require_scheme* argument is set to
     true.
-  - Discard URL authority if it matches the current hostname.
+  - Discard URL authority if it matches the local hostname.
   - Discard URL authority if it resolves to a local IP address when the new
     *resolve_netloc* argument is set to true.
   - Raise :exc:`~urllib.error.URLError` if a URL authority isn't local,

From 9e7535759072c3bd85f7b33be53f7729e6d19bad Mon Sep 17 00:00:00 2001
From: Barney Gale <barney.gale@gmail.com>
Date: Mon, 28 Apr 2025 17:48:46 +0100
Subject: [PATCH 6/9] Apply suggestions from code review
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>
Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com>
---
 Doc/library/urllib.request.rst | 2 +-
 Lib/urllib/request.py          | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/Doc/library/urllib.request.rst b/Doc/library/urllib.request.rst
index 8bd2e6833f354e..fe952f343e564f 100644
--- a/Doc/library/urllib.request.rst
+++ b/Doc/library/urllib.request.rst
@@ -185,7 +185,7 @@ The :mod:`urllib.request` module defines the following functions:
    value should include the prefix; a :exc:`~urllib.error.URLError` is raised
    if it doesn't.
 
-   The URL authority is discarded if it empty, ``localhost``, or the local
+   The URL authority is discarded if it is empty, ``localhost``, or the local
    hostname. Otherwise, if *resolve_netloc* is set to true, the authority is
    resolved using :func:`socket.gethostbyname` and discarded if it matches a
    local IP address. If the authority is still unhandled, then on Windows a
diff --git a/Lib/urllib/request.py b/Lib/urllib/request.py
index 2f9505527bb08a..390a172877e760 100644
--- a/Lib/urllib/request.py
+++ b/Lib/urllib/request.py
@@ -1643,7 +1643,7 @@ def data_open(self, req):
         return addinfourl(io.BytesIO(data), headers, url)
 
 
-# Code move from the old urllib module
+# Code moved from the old urllib module
 
 def url2pathname(url, *, require_scheme=False, resolve_netloc=False):
     """Convert the given file URL to a local file system path.

From 873c19a4d1b8588ba1063572c07195cfe74835c3 Mon Sep 17 00:00:00 2001
From: barneygale <barney.gale@gmail.com>
Date: Mon, 28 Apr 2025 18:05:03 +0100
Subject: [PATCH 7/9] Address some review feedback

---
 Doc/library/urllib.request.rst                    | 15 ++++++---------
 Doc/whatsnew/3.14.rst                             |  2 +-
 Lib/test/test_urllib.py                           |  6 +++---
 Lib/urllib/request.py                             | 10 +++++-----
 ...2024-11-14-21-17-48.gh-issue-126838.Yr5vKF.rst | 12 +++---------
 5 files changed, 18 insertions(+), 27 deletions(-)

diff --git a/Doc/library/urllib.request.rst b/Doc/library/urllib.request.rst
index fe952f343e564f..53eddad0fd03bb 100644
--- a/Doc/library/urllib.request.rst
+++ b/Doc/library/urllib.request.rst
@@ -175,7 +175,7 @@ The :mod:`urllib.request` module defines the following functions:
       The *add_scheme* argument was added.
 
 
-.. function:: url2pathname(url, *, require_scheme=False, resolve_netloc=False)
+.. function:: url2pathname(url, *, require_scheme=False, resolve_host=False)
 
    Convert the given ``file:`` URL to a local path. This function uses
    :func:`~urllib.parse.unquote` to decode the URL.
@@ -186,11 +186,11 @@ The :mod:`urllib.request` module defines the following functions:
    if it doesn't.
 
    The URL authority is discarded if it is empty, ``localhost``, or the local
-   hostname. Otherwise, if *resolve_netloc* is set to true, the authority is
+   hostname. Otherwise, if *resolve_host* is set to true, the authority is
    resolved using :func:`socket.gethostbyname` and discarded if it matches a
-   local IP address. If the authority is still unhandled, then on Windows a
-   UNC path is returned, and on other platforms a
-   :exc:`~urllib.error.URLError` is raised.
+   local IP address (as per :rfc:`RFC 8089 §3 <8089#section-3>`). If the
+   authority is still unhandled, then on Windows a UNC path is returned, and
+   on other platforms a :exc:`~urllib.error.URLError` is raised.
 
    This example shows the function being used on Windows::
 
@@ -211,10 +211,7 @@ The :mod:`urllib.request` module defines the following functions:
       :exc:`~urllib.error.URLError` is raised.
 
    .. versionchanged:: next
-      The *require_scheme* argument was added.
-
-   .. versionchanged:: next
-      The *resolve_netloc* argument was added.
+      The *require_scheme* and *resolve_host* arguments were added.
 
 
 .. function:: getproxies()
diff --git a/Doc/whatsnew/3.14.rst b/Doc/whatsnew/3.14.rst
index d2d4bad82894a0..47382d764175fe 100644
--- a/Doc/whatsnew/3.14.rst
+++ b/Doc/whatsnew/3.14.rst
@@ -1232,7 +1232,7 @@ urllib
     true.
   - Discard URL authority if it matches the local hostname.
   - Discard URL authority if it resolves to a local IP address when the new
-    *resolve_netloc* argument is set to true.
+    *resolve_host* argument is set to true.
   - Raise :exc:`~urllib.error.URLError` if a URL authority isn't local,
     except on Windows where we return a UNC path as before.
 
diff --git a/Lib/test/test_urllib.py b/Lib/test/test_urllib.py
index 00a20f92c199f2..c965860fbb10ef 100644
--- a/Lib/test/test_urllib.py
+++ b/Lib/test/test_urllib.py
@@ -1569,12 +1569,12 @@ def test_url2pathname_require_scheme_errors(self):
                     urllib.request.url2pathname,
                     url, require_scheme=True)
 
-    def test_url2pathname_resolve_netloc(self):
+    def test_url2pathname_resolve_host(self):
         fn = urllib.request.url2pathname
         sep = os.path.sep
-        self.assertEqual(fn('//127.0.0.1/foo/bar', resolve_netloc=True), f'{sep}foo{sep}bar')
+        self.assertEqual(fn('//127.0.0.1/foo/bar', resolve_host=True), f'{sep}foo{sep}bar')
         self.assertEqual(fn(f'//{socket.gethostname()}/foo/bar'), f'{sep}foo{sep}bar')
-        self.assertEqual(fn(f'//{socket.gethostname()}/foo/bar', resolve_netloc=True), f'{sep}foo{sep}bar')
+        self.assertEqual(fn(f'//{socket.gethostname()}/foo/bar', resolve_host=True), f'{sep}foo{sep}bar')
 
     @unittest.skipUnless(sys.platform == 'win32',
                          'test specific to Windows pathnames.')
diff --git a/Lib/urllib/request.py b/Lib/urllib/request.py
index 390a172877e760..32d5bdd5fdf687 100644
--- a/Lib/urllib/request.py
+++ b/Lib/urllib/request.py
@@ -1466,7 +1466,7 @@ def get_names(self):
     def open_local_file(self, req):
         import email.utils
         import mimetypes
-        localfile = url2pathname(req.full_url, require_scheme=True, resolve_netloc=True)
+        localfile = url2pathname(req.full_url, require_scheme=True, resolve_host=True)
         try:
             stats = os.stat(localfile)
             size = stats.st_size
@@ -1645,14 +1645,14 @@ def data_open(self, req):
 
 # Code moved from the old urllib module
 
-def url2pathname(url, *, require_scheme=False, resolve_netloc=False):
+def url2pathname(url, *, require_scheme=False, resolve_host=False):
     """Convert the given file URL to a local file system path.
 
     The 'file:' scheme prefix must be omitted unless *require_scheme*
     is set to true.
 
     The URL authority may be resolved with gethostbyname() if
-    *resolve_netloc* is set to true.
+    *resolve_host* is set to true.
     """
     if require_scheme:
         scheme, url = _splittype(url)
@@ -1660,7 +1660,7 @@ def url2pathname(url, *, require_scheme=False, resolve_netloc=False):
             raise URLError("URL is missing a 'file:' scheme")
     authority, url = _splithost(url)
     if os.name == 'nt':
-        if not _is_local_authority(authority, resolve_netloc):
+        if not _is_local_authority(authority, resolve_host):
             # e.g. file://server/share/file.txt
             url = '//' + authority + url
         elif url[:3] == '///':
@@ -1674,7 +1674,7 @@ def url2pathname(url, *, require_scheme=False, resolve_netloc=False):
                 # Older URLs use a pipe after a drive letter
                 url = url[:1] + ':' + url[2:]
         url = url.replace('/', '\\')
-    elif not _is_local_authority(authority, resolve_netloc):
+    elif not _is_local_authority(authority, resolve_host):
         raise URLError("file:// scheme is supported only on localhost")
     encoding = sys.getfilesystemencoding()
     errors = sys.getfilesystemencodeerrors()
diff --git a/Misc/NEWS.d/next/Library/2024-11-14-21-17-48.gh-issue-126838.Yr5vKF.rst b/Misc/NEWS.d/next/Library/2024-11-14-21-17-48.gh-issue-126838.Yr5vKF.rst
index 9b24fa2f4afe49..aac6b41b5e87f3 100644
--- a/Misc/NEWS.d/next/Library/2024-11-14-21-17-48.gh-issue-126838.Yr5vKF.rst
+++ b/Misc/NEWS.d/next/Library/2024-11-14-21-17-48.gh-issue-126838.Yr5vKF.rst
@@ -1,9 +1,3 @@
-Fix issue where :func:`urllib.request.url2pathname` mishandled file URLs with
-authorities. The process now works as follows:
-
-1. Discard authority if it is empty or ``localhost``; otherwise
-2. (New) Discard authority if it matches the local hostname; otherwise
-3. (New) If the new *resolve_netloc* keyword-only argument is set to true,
-   discard authority if it resolves to a local IP address; otherwise
-4. On Windows, return a UNC path; otherwise
-5. (New) Raise :exc:`urllib.error.URLError`.
+Add *resolve_host* keyword-only argument to
+:func:`urllib.request.url2pathname`, and fix handling of file URLs with
+authorities.

From 4bbeef68abb1213e972f4916c085c04cf6adadef Mon Sep 17 00:00:00 2001
From: Barney Gale <barney.gale@gmail.com>
Date: Mon, 5 May 2025 12:52:54 +0100
Subject: [PATCH 8/9] Update Lib/urllib/request.py

Co-authored-by: Steve Dower <steve.dower@microsoft.com>
---
 Lib/urllib/request.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Lib/urllib/request.py b/Lib/urllib/request.py
index 32d5bdd5fdf687..41dc5d7b35dedb 100644
--- a/Lib/urllib/request.py
+++ b/Lib/urllib/request.py
@@ -1498,7 +1498,7 @@ def _is_local_authority(authority, resolve):
         return False
     try:
         address = socket.gethostbyname(authority)
-    except (socket.gaierror, AttributeError):
+    except (socket.gaierror, AttributeError, UnicodeEncodeError):
         return False
     return address in FileHandler().get_names()
 

From 2a42d88012dc9c7131dba8ec02db9a1365804c00 Mon Sep 17 00:00:00 2001
From: barneygale <barney.gale@gmail.com>
Date: Mon, 5 May 2025 12:56:04 +0100
Subject: [PATCH 9/9] argument -> parameter

---
 Doc/library/urllib.request.rst                                | 4 ++--
 .../Library/2024-11-14-21-17-48.gh-issue-126838.Yr5vKF.rst    | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/Doc/library/urllib.request.rst b/Doc/library/urllib.request.rst
index 53eddad0fd03bb..234827132bfaf0 100644
--- a/Doc/library/urllib.request.rst
+++ b/Doc/library/urllib.request.rst
@@ -172,7 +172,7 @@ The :mod:`urllib.request` module defines the following functions:
       the URL ``///etc/hosts``.
 
    .. versionchanged:: next
-      The *add_scheme* argument was added.
+      The *add_scheme* parameter was added.
 
 
 .. function:: url2pathname(url, *, require_scheme=False, resolve_host=False)
@@ -211,7 +211,7 @@ The :mod:`urllib.request` module defines the following functions:
       :exc:`~urllib.error.URLError` is raised.
 
    .. versionchanged:: next
-      The *require_scheme* and *resolve_host* arguments were added.
+      The *require_scheme* and *resolve_host* parameters were added.
 
 
 .. function:: getproxies()
diff --git a/Misc/NEWS.d/next/Library/2024-11-14-21-17-48.gh-issue-126838.Yr5vKF.rst b/Misc/NEWS.d/next/Library/2024-11-14-21-17-48.gh-issue-126838.Yr5vKF.rst
index aac6b41b5e87f3..c45c22e73448db 100644
--- a/Misc/NEWS.d/next/Library/2024-11-14-21-17-48.gh-issue-126838.Yr5vKF.rst
+++ b/Misc/NEWS.d/next/Library/2024-11-14-21-17-48.gh-issue-126838.Yr5vKF.rst
@@ -1,3 +1,3 @@
-Add *resolve_host* keyword-only argument to
+Add *resolve_host* keyword-only parameter to
 :func:`urllib.request.url2pathname`, and fix handling of file URLs with
 authorities.