From eac855f514446411a2561504db8066cd49592406 Mon Sep 17 00:00:00 2001
From: barneygale <barney.gale@gmail.com>
Date: Wed, 23 Jul 2025 19:16:44 +0100
Subject: [PATCH 01/17] Stop using `pathname2url()` and `url2pathname()` in
 `urls`

`urllib.request.pathname2url()` and `url2pathname()` are:

- Fine in 3.14
- Awkward in latest 3.13 and 3.12
- Buggy in previous versions

In this patch we provide our own conversion functions (copy-pasted from the
Python 3.14 source tree), rather than calling `urllib.request` functions.
This allows us to remove workarounds for upstream bugs.
---
 ...3b-d572-41f8-b080-58cebf24b89a.trivial.rst |  0
 src/pip/_internal/utils/urls.py               | 61 +++++++++++--------
 2 files changed, 34 insertions(+), 27 deletions(-)
 create mode 100644 news/47850a3b-d572-41f8-b080-58cebf24b89a.trivial.rst

diff --git a/news/47850a3b-d572-41f8-b080-58cebf24b89a.trivial.rst b/news/47850a3b-d572-41f8-b080-58cebf24b89a.trivial.rst
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/src/pip/_internal/utils/urls.py b/src/pip/_internal/utils/urls.py
index 9f34f882a1a..26ce5ca7cc3 100644
--- a/src/pip/_internal/utils/urls.py
+++ b/src/pip/_internal/utils/urls.py
@@ -1,7 +1,6 @@
 import os
-import string
+import sys
 import urllib.parse
-import urllib.request
 
 from .compat import WINDOWS
 
@@ -12,8 +11,24 @@ def path_to_url(path: str) -> str:
     quoted path parts.
     """
     path = os.path.normpath(os.path.abspath(path))
-    url = urllib.parse.urljoin("file:", urllib.request.pathname2url(path))
-    return url
+    if WINDOWS:
+        path = path.replace("\\", "/")
+    encoding = sys.getfilesystemencoding()
+    errors = sys.getfilesystemencodeerrors()
+
+    drive, tail = os.path.splitdrive(path)
+    if drive:
+        if drive[:4] == "//?/":
+            drive = drive[4:]
+            if drive[:4].upper() == "UNC/":
+                drive = "//" + drive[4:]
+        if drive[1:] == ":":
+            drive = "///" + drive
+        drive = urllib.parse.quote(drive, "/:", encoding, errors)
+    elif tail.startswith("/"):
+        tail = "//" + tail
+    tail = urllib.parse.quote(tail, "/", encoding, errors)
+    return "file:" + drive + tail
 
 
 def url_to_path(url: str) -> str:
@@ -26,30 +41,22 @@ def url_to_path(url: str) -> str:
 
     _, netloc, path, _, _ = urllib.parse.urlsplit(url)
 
-    if not netloc or netloc == "localhost":
-        # According to RFC 8089, same as empty authority.
-        netloc = ""
-    elif WINDOWS:
-        # If we have a UNC path, prepend UNC share notation.
-        netloc = "\\\\" + netloc
-    else:
+    if WINDOWS:
+        if netloc and netloc != "localhost":
+            path = "//" + netloc + path
+        elif path[:3] == "///":
+            path = path[1:]
+        else:
+            if path[:1] == "/" and path[2:3] in (":", "|"):
+                path = path[1:]
+            if path[1:2] == "|":
+                path = path[:1] + ":" + path[2:]
+        path = path.replace("/", "\\")
+    elif netloc and netloc != "localhost":
         raise ValueError(
             f"non-local file URIs are not supported on this platform: {url!r}"
         )
 
-    path = urllib.request.url2pathname(netloc + path)
-
-    # On Windows, urlsplit parses the path as something like "/C:/Users/foo".
-    # This creates issues for path-related functions like io.open(), so we try
-    # to detect and strip the leading slash.
-    if (
-        WINDOWS
-        and not netloc  # Not UNC.
-        and len(path) >= 3
-        and path[0] == "/"  # Leading slash to strip.
-        and path[1] in string.ascii_letters  # Drive letter.
-        and path[2:4] in (":", ":/")  # Colon + end of string, or colon + absolute path.
-    ):
-        path = path[1:]
-
-    return path
+    encoding = sys.getfilesystemencoding()
+    errors = sys.getfilesystemencodeerrors()
+    return urllib.parse.unquote(path, encoding, errors)

From 3fb3599c2446b177ff807cc0c7abce29e00de22e Mon Sep 17 00:00:00 2001
From: barneygale <barney.gale@gmail.com>
Date: Wed, 23 Jul 2025 20:06:21 +0100
Subject: [PATCH 02/17] Add `clean_file_url()` utility.

---
 src/pip/_internal/models/link.py | 30 +++++------------------
 src/pip/_internal/utils/urls.py  | 20 +++++++++++++--
 src/pip/_internal/vcs/git.py     | 19 +++------------
 tests/lib/__init__.py            | 13 ----------
 tests/unit/test_collector.py     | 42 +++-----------------------------
 tests/unit/test_urls.py          | 35 +++++++++++++++++++++-----
 6 files changed, 59 insertions(+), 100 deletions(-)

diff --git a/src/pip/_internal/models/link.py b/src/pip/_internal/models/link.py
index 87651c76e25..20c7ad35333 100644
--- a/src/pip/_internal/models/link.py
+++ b/src/pip/_internal/models/link.py
@@ -24,7 +24,7 @@
     split_auth_from_netloc,
     splitext,
 )
-from pip._internal.utils.urls import path_to_url, url_to_path
+from pip._internal.utils.urls import clean_file_url, path_to_url, url_to_path
 
 if TYPE_CHECKING:
     from pip._internal.index.collector import IndexContent
@@ -121,39 +121,21 @@ def _clean_url_path_part(part: str) -> str:
     return urllib.parse.quote(urllib.parse.unquote(part))
 
 
-def _clean_file_url_path(part: str) -> str:
-    """
-    Clean the first part of a URL path that corresponds to a local
-    filesystem path (i.e. the first part after splitting on "@" characters).
-    """
-    # We unquote prior to quoting to make sure nothing is double quoted.
-    # Also, on Windows the path part might contain a drive letter which
-    # should not be quoted. On Linux where drive letters do not
-    # exist, the colon should be quoted. We rely on urllib.request
-    # to do the right thing here.
-    return urllib.request.pathname2url(urllib.request.url2pathname(part))
-
-
 # percent-encoded:                   /
 _reserved_chars_re = re.compile("(@|%2F)", re.IGNORECASE)
 
 
-def _clean_url_path(path: str, is_local_path: bool) -> str:
+def _clean_url_path(path: str) -> str:
     """
     Clean the path portion of a URL.
     """
-    if is_local_path:
-        clean_func = _clean_file_url_path
-    else:
-        clean_func = _clean_url_path_part
-
     # Split on the reserved characters prior to cleaning so that
     # revision strings in VCS URLs are properly preserved.
     parts = _reserved_chars_re.split(path)
 
     cleaned_parts = []
     for to_clean, reserved in pairwise(itertools.chain(parts, [""])):
-        cleaned_parts.append(clean_func(to_clean))
+        cleaned_parts.append(_clean_url_path_part(to_clean))
         # Normalize %xx escapes (e.g. %2f -> %2F)
         cleaned_parts.append(reserved.upper())
 
@@ -166,12 +148,12 @@ def _ensure_quoted_url(url: str) -> str:
     For example, if ' ' occurs in the URL, it will be replaced with "%20",
     and without double-quoting other characters.
     """
+    if url.startswith("file:"):
+        return clean_file_url(url)
     # Split the URL into parts according to the general structure
     # `scheme://netloc/path?query#fragment`.
     result = urllib.parse.urlsplit(url)
-    # If the netloc is empty, then the URL refers to a local filesystem path.
-    is_local_path = not result.netloc
-    path = _clean_url_path(result.path, is_local_path=is_local_path)
+    path = _clean_url_path(result.path)
     return urllib.parse.urlunsplit(result._replace(path=path))
 
 
diff --git a/src/pip/_internal/utils/urls.py b/src/pip/_internal/utils/urls.py
index 26ce5ca7cc3..5bdd5b65fad 100644
--- a/src/pip/_internal/utils/urls.py
+++ b/src/pip/_internal/utils/urls.py
@@ -5,12 +5,13 @@
 from .compat import WINDOWS
 
 
-def path_to_url(path: str) -> str:
+def path_to_url(path: str, normalize_path: bool = True) -> str:
     """
     Convert a path to a file: URL.  The path will be made absolute and have
     quoted path parts.
     """
-    path = os.path.normpath(os.path.abspath(path))
+    if normalize_path:
+        path = os.path.normpath(os.path.abspath(path))
     if WINDOWS:
         path = path.replace("\\", "/")
     encoding = sys.getfilesystemencoding()
@@ -60,3 +61,18 @@ def url_to_path(url: str) -> str:
     encoding = sys.getfilesystemencoding()
     errors = sys.getfilesystemencodeerrors()
     return urllib.parse.unquote(path, encoding, errors)
+
+
+def clean_file_url(url: str) -> str:
+    """
+    Fix up quoting and leading slashes in the given file: URL.
+
+    e.g. 'file:/c:/foo bar' --> 'file:///c:/foo%20bar'.
+    """
+    tok = "-_-PIP_AT_SYMBOL_-_"
+    orig_url = url.replace("@", tok)
+    tidy_url = path_to_url(url_to_path(orig_url), normalize_path=False)
+    orig_parts = urllib.parse.urlsplit(orig_url)
+    tidy_parts = urllib.parse.urlsplit(tidy_url)
+    merged_url = urllib.parse.urlunsplit(tidy_parts[:3] + orig_parts[3:])
+    return merged_url.replace(tok, "@")
diff --git a/src/pip/_internal/vcs/git.py b/src/pip/_internal/vcs/git.py
index 1769da791cb..f387f171d78 100644
--- a/src/pip/_internal/vcs/git.py
+++ b/src/pip/_internal/vcs/git.py
@@ -4,14 +4,13 @@
 import os.path
 import pathlib
 import re
-import urllib.parse
-import urllib.request
 from dataclasses import replace
 from typing import Any
 
 from pip._internal.exceptions import BadCommand, InstallationError
 from pip._internal.utils.misc import HiddenText, display_path, hide_url
 from pip._internal.utils.subprocess import make_command
+from pip._internal.utils.urls import clean_file_url
 from pip._internal.vcs.versioncontrol import (
     AuthInfo,
     RemoteNotFoundError,
@@ -22,10 +21,6 @@
     vcs,
 )
 
-urlsplit = urllib.parse.urlsplit
-urlunsplit = urllib.parse.urlunsplit
-
-
 logger = logging.getLogger(__name__)
 
 
@@ -502,16 +497,8 @@ def get_url_rev_and_auth(cls, url: str) -> tuple[str, str | None, AuthInfo]:
         """
         # Works around an apparent Git bug
         # (see https://article.gmane.org/gmane.comp.version-control.git/146500)
-        scheme, netloc, path, query, fragment = urlsplit(url)
-        if scheme.endswith("file"):
-            initial_slashes = path[: -len(path.lstrip("/"))]
-            newpath = initial_slashes + urllib.request.url2pathname(path).replace(
-                "\\", "/"
-            ).lstrip("/")
-            after_plus = scheme.find("+") + 1
-            url = scheme[:after_plus] + urlunsplit(
-                (scheme[after_plus:], netloc, newpath, query, fragment),
-            )
+        if url.startswith("git+file:"):
+            url = "git+" + clean_file_url(url[4:])
 
         if "://" not in url:
             assert "file:" not in url
diff --git a/tests/lib/__init__.py b/tests/lib/__init__.py
index d67271e1885..5c050448524 100644
--- a/tests/lib/__init__.py
+++ b/tests/lib/__init__.py
@@ -17,7 +17,6 @@
 from textwrap import dedent
 from typing import Any, AnyStr, Callable, Literal, Protocol, Union, cast
 from urllib.parse import urlparse, urlunparse
-from urllib.request import pathname2url
 from zipfile import ZipFile
 
 import pytest
@@ -1385,15 +1384,3 @@ def __call__(
     sys.platform != "win32" or has_new_urlun_behavior,
     reason="testing windows behavior for older CPython",
 )
-
-# Trailing slashes are now preserved on Windows, matching POSIX behaviour.
-# BPO: https://github.com/python/cpython/issues/126212
-does_pathname2url_preserve_trailing_slash = pathname2url("C:/foo/").endswith("/")
-skip_needs_new_pathname2url_trailing_slash_behavior_win = pytest.mark.skipif(
-    sys.platform != "win32" or not does_pathname2url_preserve_trailing_slash,
-    reason="testing windows (pathname2url) behavior for newer CPython",
-)
-skip_needs_old_pathname2url_trailing_slash_behavior_win = pytest.mark.skipif(
-    sys.platform != "win32" or does_pathname2url_preserve_trailing_slash,
-    reason="testing windows (pathname2url) behavior for older CPython",
-)
diff --git a/tests/unit/test_collector.py b/tests/unit/test_collector.py
index d95fa10fea3..fd4ab55e05a 100644
--- a/tests/unit/test_collector.py
+++ b/tests/unit/test_collector.py
@@ -41,9 +41,7 @@
 from tests.lib import (
     TestData,
     make_test_link_collector,
-    skip_needs_new_pathname2url_trailing_slash_behavior_win,
     skip_needs_new_urlun_behavior_win,
-    skip_needs_old_pathname2url_trailing_slash_behavior_win,
     skip_needs_old_urlun_behavior_win,
 )
 
@@ -298,32 +296,8 @@ def test_get_simple_response_dont_log_clear_text_password(
         ("a %2f b", "a%20%2F%20b"),
     ],
 )
-@pytest.mark.parametrize("is_local_path", [True, False])
-def test_clean_url_path(path: str, expected: str, is_local_path: bool) -> None:
-    assert _clean_url_path(path, is_local_path=is_local_path) == expected
-
-
-@pytest.mark.parametrize(
-    "path, expected",
-    [
-        # Test a VCS path with a Windows drive letter and revision.
-        pytest.param(
-            "/T:/with space/repo.git@1.0",
-            "///T:/with%20space/repo.git@1.0",
-            marks=pytest.mark.skipif("sys.platform != 'win32'"),
-        ),
-        # Test a VCS path with a Windows drive letter and revision,
-        # running on non-windows platform.
-        pytest.param(
-            "/T:/with space/repo.git@1.0",
-            "/T%3A/with%20space/repo.git@1.0",
-            marks=pytest.mark.skipif("sys.platform == 'win32'"),
-        ),
-    ],
-)
-def test_clean_url_path_with_local_path(path: str, expected: str) -> None:
-    actual = _clean_url_path(path, is_local_path=True)
-    assert actual == expected
+def test_clean_url_path(path: str, expected: str) -> None:
+    assert _clean_url_path(path) == expected
 
 
 @pytest.mark.parametrize(
@@ -392,18 +366,9 @@ def test_clean_url_path_with_local_path(path: str, expected: str) -> None:
         # removed.
         pytest.param(
             "file:///T:/path/with spaces/",
-            "file:///T:/path/with%20spaces",
+            "file:///T:/path/with%20spaces/",
             marks=[
                 skip_needs_old_urlun_behavior_win,
-                skip_needs_old_pathname2url_trailing_slash_behavior_win,
-            ],
-        ),
-        pytest.param(
-            "file:///T:/path/with spaces/",
-            "file://///T:/path/with%20spaces",
-            marks=[
-                skip_needs_new_urlun_behavior_win,
-                skip_needs_old_pathname2url_trailing_slash_behavior_win,
             ],
         ),
         pytest.param(
@@ -411,7 +376,6 @@ def test_clean_url_path_with_local_path(path: str, expected: str) -> None:
             "file://///T:/path/with%20spaces/",
             marks=[
                 skip_needs_new_urlun_behavior_win,
-                skip_needs_new_pathname2url_trailing_slash_behavior_win,
             ],
         ),
         # URL with Windows drive letter, running on non-windows
diff --git a/tests/unit/test_urls.py b/tests/unit/test_urls.py
index 0c145255080..e63d84c2625 100644
--- a/tests/unit/test_urls.py
+++ b/tests/unit/test_urls.py
@@ -4,7 +4,7 @@
 
 import pytest
 
-from pip._internal.utils.urls import path_to_url, url_to_path
+from pip._internal.utils.urls import clean_file_url, path_to_url, url_to_path
 
 
 @pytest.mark.skipif("sys.platform == 'win32'")
@@ -18,8 +18,8 @@ def test_path_to_url_unix() -> None:
 @pytest.mark.parametrize(
     "path, url",
     [
-        pytest.param("c:/tmp/file", "file:///C:/tmp/file", id="posix-path"),
-        pytest.param("c:\\tmp\\file", "file:///C:/tmp/file", id="nt-path"),
+        pytest.param("c:/tmp/file", "file:///c:/tmp/file", id="posix-path"),
+        pytest.param("c:\\tmp\\file", "file:///c:/tmp/file", id="nt-path"),
     ],
 )
 def test_path_to_url_win(path: str, url: str) -> None:
@@ -46,13 +46,13 @@ def test_relative_path_to_url_win() -> None:
     "url,win_expected,non_win_expected",
     [
         ("file:tmp", "tmp", "tmp"),
-        ("file:c:/path/to/file", r"C:\path\to\file", "c:/path/to/file"),
+        ("file:c:/path/to/file", r"c:\path\to\file", "c:/path/to/file"),
         ("file:/path/to/file", r"\path\to\file", "/path/to/file"),
         ("file://localhost/tmp/file", r"\tmp\file", "/tmp/file"),
-        ("file://localhost/c:/tmp/file", r"C:\tmp\file", "/c:/tmp/file"),
+        ("file://localhost/c:/tmp/file", r"c:\tmp\file", "/c:/tmp/file"),
         ("file://somehost/tmp/file", r"\\somehost\tmp\file", None),
         ("file:///tmp/file", r"\tmp\file", "/tmp/file"),
-        ("file:///c:/tmp/file", r"C:\tmp\file", "/c:/tmp/file"),
+        ("file:///c:/tmp/file", r"c:\tmp\file", "/c:/tmp/file"),
     ],
 )
 def test_url_to_path(url: str, win_expected: str, non_win_expected: str) -> None:
@@ -75,3 +75,26 @@ def test_url_to_path_path_to_url_symmetry_win() -> None:
 
     unc_path = r"\\unc\share\path"
     assert url_to_path(path_to_url(unc_path)) == unc_path
+
+
+@pytest.mark.parametrize(
+    "url, expected",
+    [
+        # Test a VCS path with a Windows drive letter and revision.
+        pytest.param(
+            "file:/T:/with space/repo.git@1.0",
+            "file:///T:/with%20space/repo.git@1.0",
+            marks=pytest.mark.skipif("sys.platform != 'win32'"),
+        ),
+        # Test a VCS path with a Windows drive letter and revision,
+        # running on non-windows platform.
+        pytest.param(
+            "file:/T:/with space/repo.git@1.0",
+            "file:///T%3A/with%20space/repo.git@1.0",
+            marks=pytest.mark.skipif("sys.platform == 'win32'"),
+        ),
+    ],
+)
+def test_clean_file_url(url: str, expected: str) -> None:
+    actual = clean_file_url(url)
+    assert actual == expected

From 9860f51d0dc43f205871d8d05be0806aee577aa4 Mon Sep 17 00:00:00 2001
From: barneygale <barney.gale@gmail.com>
Date: Wed, 23 Jul 2025 20:29:02 +0100
Subject: [PATCH 03/17] Windows tests fixes

---
 src/pip/_internal/models/link.py |  5 +++--
 src/pip/_internal/utils/urls.py  | 13 +++++++------
 src/pip/_internal/vcs/git.py     |  2 +-
 tests/lib/__init__.py            | 21 ---------------------
 tests/unit/test_collector.py     | 27 ++++-----------------------
 5 files changed, 15 insertions(+), 53 deletions(-)

diff --git a/src/pip/_internal/models/link.py b/src/pip/_internal/models/link.py
index 20c7ad35333..4181d1e402a 100644
--- a/src/pip/_internal/models/link.py
+++ b/src/pip/_internal/models/link.py
@@ -148,11 +148,12 @@ def _ensure_quoted_url(url: str) -> str:
     For example, if ' ' occurs in the URL, it will be replaced with "%20",
     and without double-quoting other characters.
     """
-    if url.startswith("file:"):
-        return clean_file_url(url)
     # Split the URL into parts according to the general structure
     # `scheme://netloc/path?query#fragment`.
     result = urllib.parse.urlsplit(url)
+    # If the netloc is empty, then the URL refers to a local filesystem path
+    if not result.netloc:
+        return clean_file_url(url)
     path = _clean_url_path(result.path)
     return urllib.parse.urlunsplit(result._replace(path=path))
 
diff --git a/src/pip/_internal/utils/urls.py b/src/pip/_internal/utils/urls.py
index 5bdd5b65fad..43145ac79d8 100644
--- a/src/pip/_internal/utils/urls.py
+++ b/src/pip/_internal/utils/urls.py
@@ -36,11 +36,9 @@ def url_to_path(url: str) -> str:
     """
     Convert a file: URL to a path.
     """
-    assert url.startswith(
-        "file:"
-    ), f"You can only turn file: urls into filenames (not {url!r})"
-
-    _, netloc, path, _, _ = urllib.parse.urlsplit(url)
+    scheme, netloc, path, _, _ = urllib.parse.urlsplit(url)
+    if scheme != "file" and not scheme.endswith("+file"):
+        raise ValueError(f"You can only turn file: urls into filenames (not {url!r})")
 
     if WINDOWS:
         if netloc and netloc != "localhost":
@@ -70,9 +68,12 @@ def clean_file_url(url: str) -> str:
     e.g. 'file:/c:/foo bar' --> 'file:///c:/foo%20bar'.
     """
     tok = "-_-PIP_AT_SYMBOL_-_"
+    assert tok not in url
     orig_url = url.replace("@", tok)
     tidy_url = path_to_url(url_to_path(orig_url), normalize_path=False)
-    orig_parts = urllib.parse.urlsplit(orig_url)
     tidy_parts = urllib.parse.urlsplit(tidy_url)
+    orig_parts = urllib.parse.urlsplit(orig_url)
     merged_url = urllib.parse.urlunsplit(tidy_parts[:3] + orig_parts[3:])
+    if orig_parts.scheme != "file":
+        merged_url = orig_parts.scheme + merged_url[4:]
     return merged_url.replace(tok, "@")
diff --git a/src/pip/_internal/vcs/git.py b/src/pip/_internal/vcs/git.py
index f387f171d78..dba49389d77 100644
--- a/src/pip/_internal/vcs/git.py
+++ b/src/pip/_internal/vcs/git.py
@@ -498,7 +498,7 @@ def get_url_rev_and_auth(cls, url: str) -> tuple[str, str | None, AuthInfo]:
         # Works around an apparent Git bug
         # (see https://article.gmane.org/gmane.comp.version-control.git/146500)
         if url.startswith("git+file:"):
-            url = "git+" + clean_file_url(url[4:])
+            url = clean_file_url(url)
 
         if "://" not in url:
             assert "file:" not in url
diff --git a/tests/lib/__init__.py b/tests/lib/__init__.py
index 5c050448524..01a5955572c 100644
--- a/tests/lib/__init__.py
+++ b/tests/lib/__init__.py
@@ -16,7 +16,6 @@
 from io import BytesIO, StringIO
 from textwrap import dedent
 from typing import Any, AnyStr, Callable, Literal, Protocol, Union, cast
-from urllib.parse import urlparse, urlunparse
 from zipfile import ZipFile
 
 import pytest
@@ -1364,23 +1363,3 @@ def __call__(
 
 
 CertFactory = Callable[[], str]
-
-# -------------------------------------------------------------------------
-# Accommodations for Windows path and URL changes in recent Python releases
-# -------------------------------------------------------------------------
-
-# versions containing fix/backport from https://github.com/python/cpython/pull/113563
-# which changed the behavior of `urllib.parse.urlun{parse,split}`
-url = "////path/to/file"
-has_new_urlun_behavior = url == urlunparse(urlparse(url))
-
-# the above change seems to only impact tests on Windows, so just add skips for that
-skip_needs_new_urlun_behavior_win = pytest.mark.skipif(
-    sys.platform != "win32" or not has_new_urlun_behavior,
-    reason="testing windows behavior for newer CPython",
-)
-
-skip_needs_old_urlun_behavior_win = pytest.mark.skipif(
-    sys.platform != "win32" or has_new_urlun_behavior,
-    reason="testing windows behavior for older CPython",
-)
diff --git a/tests/unit/test_collector.py b/tests/unit/test_collector.py
index fd4ab55e05a..6b306c53432 100644
--- a/tests/unit/test_collector.py
+++ b/tests/unit/test_collector.py
@@ -38,12 +38,7 @@
 )
 from pip._internal.network.session import PipSession
 
-from tests.lib import (
-    TestData,
-    make_test_link_collector,
-    skip_needs_new_urlun_behavior_win,
-    skip_needs_old_urlun_behavior_win,
-)
+from tests.lib import TestData, make_test_link_collector
 
 ACCEPT = ", ".join(
     [
@@ -367,16 +362,7 @@ def test_clean_url_path(path: str, expected: str) -> None:
         pytest.param(
             "file:///T:/path/with spaces/",
             "file:///T:/path/with%20spaces/",
-            marks=[
-                skip_needs_old_urlun_behavior_win,
-            ],
-        ),
-        pytest.param(
-            "file:///T:/path/with spaces/",
-            "file://///T:/path/with%20spaces/",
-            marks=[
-                skip_needs_new_urlun_behavior_win,
-            ],
+            marks=pytest.mark.skipif("sys.platform != 'win32'"),
         ),
         # URL with Windows drive letter, running on non-windows
         # platform. The `:` after the drive should be quoted.
@@ -389,18 +375,13 @@ def test_clean_url_path(path: str, expected: str) -> None:
         pytest.param(
             "git+file:///T:/with space/repo.git@1.0#egg=my-package-1.0",
             "git+file:///T:/with%20space/repo.git@1.0#egg=my-package-1.0",
-            marks=skip_needs_old_urlun_behavior_win,
-        ),
-        pytest.param(
-            "git+file:///T:/with space/repo.git@1.0#egg=my-package-1.0",
-            "git+file://///T:/with%20space/repo.git@1.0#egg=my-package-1.0",
-            marks=skip_needs_new_urlun_behavior_win,
+            marks=pytest.mark.skipif("sys.platform != 'win32'"),
         ),
         # Test a VCS URL with a Windows drive letter and revision,
         # running on non-windows platform.
         pytest.param(
             "git+file:///T:/with space/repo.git@1.0#egg=my-package-1.0",
-            "git+file:/T%3A/with%20space/repo.git@1.0#egg=my-package-1.0",
+            "git+file:///T%3A/with%20space/repo.git@1.0#egg=my-package-1.0",
             marks=pytest.mark.skipif("sys.platform == 'win32'"),
         ),
     ],

From 2f3d8d990f69ceca9ffbb187d5a274d223756e14 Mon Sep 17 00:00:00 2001
From: barneygale <barney.gale@gmail.com>
Date: Wed, 23 Jul 2025 21:13:05 +0100
Subject: [PATCH 04/17] More Windows gubbins

---
 src/pip/_internal/models/link.py | 2 +-
 tests/unit/test_req.py           | 3 ++-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/pip/_internal/models/link.py b/src/pip/_internal/models/link.py
index 4181d1e402a..dc18e752a1c 100644
--- a/src/pip/_internal/models/link.py
+++ b/src/pip/_internal/models/link.py
@@ -151,7 +151,7 @@ def _ensure_quoted_url(url: str) -> str:
     # Split the URL into parts according to the general structure
     # `scheme://netloc/path?query#fragment`.
     result = urllib.parse.urlsplit(url)
-    # If the netloc is empty, then the URL refers to a local filesystem path
+    # If the netloc is empty, then the URL refers to a local filesystem path.
     if not result.netloc:
         return clean_file_url(url)
     path = _clean_url_path(result.path)
diff --git a/tests/unit/test_req.py b/tests/unit/test_req.py
index 0547131134e..f0d30c00634 100644
--- a/tests/unit/test_req.py
+++ b/tests/unit/test_req.py
@@ -51,6 +51,7 @@
     handle_requirement_line,
 )
 from pip._internal.resolution.legacy.resolver import Resolver
+from pip._internal.utils.urls import url_to_path
 
 from tests.lib import TestData, make_test_finder, requirements_file, wheel
 
@@ -224,7 +225,7 @@ def test_unsupported_hashes(self, data: TestData) -> None:
         dir_path = data.packages.joinpath("FSPkg")
         reqset.add_unnamed_requirement(
             get_processed_req_from_line(
-                f"file://{dir_path}",
+                url_to_path(dir_path),
                 lineno=2,
             )
         )

From 60edfd85dd69a6960e8b123b9b00111e7434d8dc Mon Sep 17 00:00:00 2001
From: barneygale <barney.gale@gmail.com>
Date: Wed, 23 Jul 2025 21:17:09 +0100
Subject: [PATCH 05/17] Tweak

---
 tests/unit/test_req.py | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/tests/unit/test_req.py b/tests/unit/test_req.py
index f0d30c00634..69152dedfa9 100644
--- a/tests/unit/test_req.py
+++ b/tests/unit/test_req.py
@@ -51,7 +51,6 @@
     handle_requirement_line,
 )
 from pip._internal.resolution.legacy.resolver import Resolver
-from pip._internal.utils.urls import url_to_path
 
 from tests.lib import TestData, make_test_finder, requirements_file, wheel
 
@@ -225,7 +224,7 @@ def test_unsupported_hashes(self, data: TestData) -> None:
         dir_path = data.packages.joinpath("FSPkg")
         reqset.add_unnamed_requirement(
             get_processed_req_from_line(
-                url_to_path(dir_path),
+                f"file:{dir_path}",
                 lineno=2,
             )
         )

From 0757e0d2254fd75b1db533a12301d3d487bda81e Mon Sep 17 00:00:00 2001
From: barneygale <barney.gale@gmail.com>
Date: Wed, 23 Jul 2025 21:22:08 +0100
Subject: [PATCH 06/17] Tweak test regex

---
 tests/unit/test_req.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/unit/test_req.py b/tests/unit/test_req.py
index 69152dedfa9..e0074c5de4c 100644
--- a/tests/unit/test_req.py
+++ b/tests/unit/test_req.py
@@ -244,7 +244,7 @@ def test_unsupported_hashes(self, data: TestData) -> None:
                     r"file \(line 1\)\)\n"
                     r"Can't verify hashes for these file:// requirements because "
                     r"they point to directories:\n"
-                    rf"    file://.*{sep}data{sep}packages{sep}FSPkg "
+                    rf"    file:.*{sep}data{sep}packages{sep}FSPkg "
                     r"\(from -r file \(line 2\)\)"
                 ),
             ):

From f846efde00241a6a86e332e789be69a55ec4aee1 Mon Sep 17 00:00:00 2001
From: barneygale <barney.gale@gmail.com>
Date: Wed, 23 Jul 2025 21:34:19 +0100
Subject: [PATCH 07/17] More Windows test fixes, cleanups.

---
 src/pip/_internal/utils/urls.py  | 7 ++++---
 tests/functional/test_install.py | 2 +-
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/pip/_internal/utils/urls.py b/src/pip/_internal/utils/urls.py
index 43145ac79d8..567cdded679 100644
--- a/src/pip/_internal/utils/urls.py
+++ b/src/pip/_internal/utils/urls.py
@@ -11,7 +11,7 @@ def path_to_url(path: str, normalize_path: bool = True) -> str:
     quoted path parts.
     """
     if normalize_path:
-        path = os.path.normpath(os.path.abspath(path))
+        path = os.path.abspath(path)
     if WINDOWS:
         path = path.replace("\\", "/")
     encoding = sys.getfilesystemencoding()
@@ -37,8 +37,9 @@ def url_to_path(url: str) -> str:
     Convert a file: URL to a path.
     """
     scheme, netloc, path, _, _ = urllib.parse.urlsplit(url)
-    if scheme != "file" and not scheme.endswith("+file"):
-        raise ValueError(f"You can only turn file: urls into filenames (not {url!r})")
+    assert scheme == "file" or scheme.endswith(
+        "+file"
+    ), f"You can only turn file: urls into filenames (not {url!r})"
 
     if WINDOWS:
         if netloc and netloc != "localhost":
diff --git a/tests/functional/test_install.py b/tests/functional/test_install.py
index f23b156dcf7..8c4e1682a4a 100644
--- a/tests/functional/test_install.py
+++ b/tests/functional/test_install.py
@@ -1880,7 +1880,7 @@ def test_install_editable_with_wrong_egg_name(
     result = script.pip(
         "install",
         "--editable",
-        f"file://{pkga_path}#egg=pkgb",
+        f"file:{pkga_path}#egg=pkgb",
         expect_error=(resolver_variant == "resolvelib"),
     )
     assert (

From 359557e1144bc9e88cea5a1c593988ba02ec91c7 Mon Sep 17 00:00:00 2001
From: barneygale <barney.gale@gmail.com>
Date: Wed, 23 Jul 2025 22:00:24 +0100
Subject: [PATCH 08/17] Undo test changes

---
 src/pip/_internal/utils/urls.py  | 7 +++++--
 tests/functional/test_install.py | 2 +-
 tests/unit/test_req.py           | 4 ++--
 3 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/src/pip/_internal/utils/urls.py b/src/pip/_internal/utils/urls.py
index 567cdded679..f99e6c26905 100644
--- a/src/pip/_internal/utils/urls.py
+++ b/src/pip/_internal/utils/urls.py
@@ -42,8 +42,11 @@ def url_to_path(url: str) -> str:
     ), f"You can only turn file: urls into filenames (not {url!r})"
 
     if WINDOWS:
-        if netloc and netloc != "localhost":
-            path = "//" + netloc + path
+        if netloc:
+            if netloc[1:] == ":":
+                path = netloc + path
+            elif netloc != "localhost":
+                path = "//" + netloc + path
         elif path[:3] == "///":
             path = path[1:]
         else:
diff --git a/tests/functional/test_install.py b/tests/functional/test_install.py
index 8c4e1682a4a..f23b156dcf7 100644
--- a/tests/functional/test_install.py
+++ b/tests/functional/test_install.py
@@ -1880,7 +1880,7 @@ def test_install_editable_with_wrong_egg_name(
     result = script.pip(
         "install",
         "--editable",
-        f"file:{pkga_path}#egg=pkgb",
+        f"file://{pkga_path}#egg=pkgb",
         expect_error=(resolver_variant == "resolvelib"),
     )
     assert (
diff --git a/tests/unit/test_req.py b/tests/unit/test_req.py
index e0074c5de4c..0547131134e 100644
--- a/tests/unit/test_req.py
+++ b/tests/unit/test_req.py
@@ -224,7 +224,7 @@ def test_unsupported_hashes(self, data: TestData) -> None:
         dir_path = data.packages.joinpath("FSPkg")
         reqset.add_unnamed_requirement(
             get_processed_req_from_line(
-                f"file:{dir_path}",
+                f"file://{dir_path}",
                 lineno=2,
             )
         )
@@ -244,7 +244,7 @@ def test_unsupported_hashes(self, data: TestData) -> None:
                     r"file \(line 1\)\)\n"
                     r"Can't verify hashes for these file:// requirements because "
                     r"they point to directories:\n"
-                    rf"    file:.*{sep}data{sep}packages{sep}FSPkg "
+                    rf"    file://.*{sep}data{sep}packages{sep}FSPkg "
                     r"\(from -r file \(line 2\)\)"
                 ),
             ):

From d07a876732c2c3283dd2696e688ac673a777154c Mon Sep 17 00:00:00 2001
From: barneygale <barney.gale@gmail.com>
Date: Wed, 23 Jul 2025 22:19:26 +0100
Subject: [PATCH 09/17] Support backslashes in URLs

---
 src/pip/_internal/utils/urls.py | 25 ++++++++++++-------------
 1 file changed, 12 insertions(+), 13 deletions(-)

diff --git a/src/pip/_internal/utils/urls.py b/src/pip/_internal/utils/urls.py
index f99e6c26905..d668650cf47 100644
--- a/src/pip/_internal/utils/urls.py
+++ b/src/pip/_internal/utils/urls.py
@@ -42,11 +42,10 @@ def url_to_path(url: str) -> str:
     ), f"You can only turn file: urls into filenames (not {url!r})"
 
     if WINDOWS:
-        if netloc:
-            if netloc[1:] == ":":
-                path = netloc + path
-            elif netloc != "localhost":
-                path = "//" + netloc + path
+        if netloc[1:2] == ":":
+            path = netloc + path
+        elif netloc and netloc != "localhost":
+            path = "//" + netloc + path
         elif path[:3] == "///":
             path = path[1:]
         else:
@@ -71,13 +70,13 @@ def clean_file_url(url: str) -> str:
 
     e.g. 'file:/c:/foo bar' --> 'file:///c:/foo%20bar'.
     """
-    tok = "-_-PIP_AT_SYMBOL_-_"
-    assert tok not in url
-    orig_url = url.replace("@", tok)
+    at_symbol_token = "-_-PIP_AT_SYMBOL_-_"
+    assert at_symbol_token not in url
+    orig_url = url.replace("@", at_symbol_token)
     tidy_url = path_to_url(url_to_path(orig_url), normalize_path=False)
-    tidy_parts = urllib.parse.urlsplit(tidy_url)
     orig_parts = urllib.parse.urlsplit(orig_url)
-    merged_url = urllib.parse.urlunsplit(tidy_parts[:3] + orig_parts[3:])
-    if orig_parts.scheme != "file":
-        merged_url = orig_parts.scheme + merged_url[4:]
-    return merged_url.replace(tok, "@")
+    tidy_parts = urllib.parse.urlsplit(tidy_url)
+    url = urllib.parse.urlunsplit(tidy_parts[:3] + orig_parts[3:])
+    url = url.replace(tidy_parts.scheme, orig_parts.scheme, 1)
+    url = url.replace(at_symbol_token, "@")
+    return url

From 071a7e3bd4dfdaac78302f6dc1700e5c55fb3cbf Mon Sep 17 00:00:00 2001
From: barneygale <barney.gale@gmail.com>
Date: Wed, 23 Jul 2025 22:37:10 +0100
Subject: [PATCH 10/17] Add news blurb

---
 news/13501.bugfix.rst                                 | 1 +
 news/47850a3b-d572-41f8-b080-58cebf24b89a.trivial.rst | 0
 2 files changed, 1 insertion(+)
 create mode 100644 news/13501.bugfix.rst
 delete mode 100644 news/47850a3b-d572-41f8-b080-58cebf24b89a.trivial.rst

diff --git a/news/13501.bugfix.rst b/news/13501.bugfix.rst
new file mode 100644
index 00000000000..cb06bbb90d1
--- /dev/null
+++ b/news/13501.bugfix.rst
@@ -0,0 +1 @@
+Make conversion of file URLs more consistent across Python versions.
diff --git a/news/47850a3b-d572-41f8-b080-58cebf24b89a.trivial.rst b/news/47850a3b-d572-41f8-b080-58cebf24b89a.trivial.rst
deleted file mode 100644
index e69de29bb2d..00000000000

From 5c23ec0a29f170ae024b5c7b0a9067eb20f93357 Mon Sep 17 00:00:00 2001
From: barneygale <barney.gale@gmail.com>
Date: Wed, 23 Jul 2025 23:25:15 +0100
Subject: [PATCH 11/17] Add comments, improve naming.

---
 src/pip/_internal/utils/urls.py | 43 +++++++++++++++++++++------------
 1 file changed, 28 insertions(+), 15 deletions(-)

diff --git a/src/pip/_internal/utils/urls.py b/src/pip/_internal/utils/urls.py
index d668650cf47..bfa3f0b88a2 100644
--- a/src/pip/_internal/utils/urls.py
+++ b/src/pip/_internal/utils/urls.py
@@ -14,8 +14,6 @@ def path_to_url(path: str, normalize_path: bool = True) -> str:
         path = os.path.abspath(path)
     if WINDOWS:
         path = path.replace("\\", "/")
-    encoding = sys.getfilesystemencoding()
-    errors = sys.getfilesystemencodeerrors()
 
     drive, tail = os.path.splitdrive(path)
     if drive:
@@ -25,9 +23,12 @@ def path_to_url(path: str, normalize_path: bool = True) -> str:
                 drive = "//" + drive[4:]
         if drive[1:] == ":":
             drive = "///" + drive
-        drive = urllib.parse.quote(drive, "/:", encoding, errors)
     elif tail.startswith("/"):
         tail = "//" + tail
+
+    encoding = sys.getfilesystemencoding()
+    errors = sys.getfilesystemencodeerrors()
+    drive = urllib.parse.quote(drive, "/:", encoding, errors)
     tail = urllib.parse.quote(tail, "/", encoding, errors)
     return "file:" + drive + tail
 
@@ -42,17 +43,22 @@ def url_to_path(url: str) -> str:
     ), f"You can only turn file: urls into filenames (not {url!r})"
 
     if WINDOWS:
+        # e.g. file://c:/foo
         if netloc[1:2] == ":":
             path = netloc + path
+
+        # e.g. file://server/share/foo
         elif netloc and netloc != "localhost":
             path = "//" + netloc + path
+
+        # e.g. file://///server/share/foo
         elif path[:3] == "///":
             path = path[1:]
-        else:
-            if path[:1] == "/" and path[2:3] in (":", "|"):
-                path = path[1:]
-            if path[1:2] == "|":
-                path = path[:1] + ":" + path[2:]
+
+        # e.g. file:///c:/foo
+        elif path[:1] == "/" and path[2:3] == ":":
+            path = path[1:]
+
         path = path.replace("/", "\\")
     elif netloc and netloc != "localhost":
         raise ValueError(
@@ -70,13 +76,20 @@ def clean_file_url(url: str) -> str:
 
     e.g. 'file:/c:/foo bar' --> 'file:///c:/foo%20bar'.
     """
+    # Replace "@" characters to protect them from percent-encoding.
     at_symbol_token = "-_-PIP_AT_SYMBOL_-_"
     assert at_symbol_token not in url
-    orig_url = url.replace("@", at_symbol_token)
-    tidy_url = path_to_url(url_to_path(orig_url), normalize_path=False)
-    orig_parts = urllib.parse.urlsplit(orig_url)
+    url = url.replace("@", at_symbol_token)
+    parts = urllib.parse.urlsplit(url)
+
+    # Convert to a file path and back. This normalizes the URL, but removes
+    # the original scheme, query and fragment components.
+    tidy_url = path_to_url(url_to_path(url), normalize_path=False)
     tidy_parts = urllib.parse.urlsplit(tidy_url)
-    url = urllib.parse.urlunsplit(tidy_parts[:3] + orig_parts[3:])
-    url = url.replace(tidy_parts.scheme, orig_parts.scheme, 1)
-    url = url.replace(at_symbol_token, "@")
-    return url
+
+    # Restore the original scheme, query and fragment components.
+    url = urllib.parse.urlunsplit(tidy_parts[:3] + parts[3:])
+    url = url.replace(tidy_parts.scheme, parts.scheme, 1)
+
+    # Restore "@" characters that were replaced earlier.
+    return url.replace(at_symbol_token, "@")

From 8c817be90afb972cb77bb51d789ae82f3b6a7cee Mon Sep 17 00:00:00 2001
From: barneygale <barney.gale@gmail.com>
Date: Wed, 23 Jul 2025 23:39:13 +0100
Subject: [PATCH 12/17] =?UTF-8?q?Enable=20Python=203.14=20CI=20?=
 =?UTF-8?q?=F0=9F=A4=9E?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .github/workflows/ci.yml | 2 ++
 noxfile.py               | 2 +-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 815617e1c19..f3d69fa5763 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -122,6 +122,7 @@ jobs:
           - "3.11"
           - "3.12"
           - "3.13"
+          - "3.14"
 
     steps:
       - uses: actions/checkout@v4
@@ -181,6 +182,7 @@ jobs:
           # - "3.11"
           # - "3.12"
           - "3.13"
+          - "3.14"
         group:
           - { number: 1, pytest-filter: "not test_install" }
           - { number: 2, pytest-filter: "test_install" }
diff --git a/noxfile.py b/noxfile.py
index 160e823e9f1..88e9d5dec66 100644
--- a/noxfile.py
+++ b/noxfile.py
@@ -67,7 +67,7 @@ def should_update_common_wheels() -> bool:
 # -----------------------------------------------------------------------------
 # Development Commands
 # -----------------------------------------------------------------------------
-@nox.session(python=["3.9", "3.10", "3.11", "3.12", "3.13", "pypy3"])
+@nox.session(python=["3.9", "3.10", "3.11", "3.12", "3.13", "3.14", "pypy3"])
 def test(session: nox.Session) -> None:
     # Get the common wheels.
     if should_update_common_wheels():

From b2997be9a809129fd229eecfb9bc61b0eb7a9dfd Mon Sep 17 00:00:00 2001
From: barneygale <barney.gale@gmail.com>
Date: Thu, 24 Jul 2025 18:06:00 +0100
Subject: [PATCH 13/17] Undo drive letter case change

---
 tests/unit/test_urls.py | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/tests/unit/test_urls.py b/tests/unit/test_urls.py
index e63d84c2625..b88356c0caa 100644
--- a/tests/unit/test_urls.py
+++ b/tests/unit/test_urls.py
@@ -18,8 +18,8 @@ def test_path_to_url_unix() -> None:
 @pytest.mark.parametrize(
     "path, url",
     [
-        pytest.param("c:/tmp/file", "file:///c:/tmp/file", id="posix-path"),
-        pytest.param("c:\\tmp\\file", "file:///c:/tmp/file", id="nt-path"),
+        pytest.param("c:/tmp/file", "file:///C:/tmp/file", id="posix-path"),
+        pytest.param("c:\\tmp\\file", "file:///C:/tmp/file", id="nt-path"),
     ],
 )
 def test_path_to_url_win(path: str, url: str) -> None:
@@ -46,13 +46,13 @@ def test_relative_path_to_url_win() -> None:
     "url,win_expected,non_win_expected",
     [
         ("file:tmp", "tmp", "tmp"),
-        ("file:c:/path/to/file", r"c:\path\to\file", "c:/path/to/file"),
+        ("file:c:/path/to/file", r"C:\path\to\file", "c:/path/to/file"),
         ("file:/path/to/file", r"\path\to\file", "/path/to/file"),
         ("file://localhost/tmp/file", r"\tmp\file", "/tmp/file"),
-        ("file://localhost/c:/tmp/file", r"c:\tmp\file", "/c:/tmp/file"),
+        ("file://localhost/c:/tmp/file", r"C:\tmp\file", "/c:/tmp/file"),
         ("file://somehost/tmp/file", r"\\somehost\tmp\file", None),
         ("file:///tmp/file", r"\tmp\file", "/tmp/file"),
-        ("file:///c:/tmp/file", r"c:\tmp\file", "/c:/tmp/file"),
+        ("file:///c:/tmp/file", r"C:\tmp\file", "/c:/tmp/file"),
     ],
 )
 def test_url_to_path(url: str, win_expected: str, non_win_expected: str) -> None:

From 7db59a0840be92cfea4c05849f57f2a5a455dc6f Mon Sep 17 00:00:00 2001
From: barneygale <barney.gale@gmail.com>
Date: Thu, 24 Jul 2025 19:51:18 +0100
Subject: [PATCH 14/17] Very minor tweaks

---
 src/pip/_internal/utils/urls.py | 14 +++++++-------
 tests/unit/test_collector.py    |  2 +-
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/src/pip/_internal/utils/urls.py b/src/pip/_internal/utils/urls.py
index bfa3f0b88a2..989311c016c 100644
--- a/src/pip/_internal/utils/urls.py
+++ b/src/pip/_internal/utils/urls.py
@@ -7,8 +7,8 @@
 
 def path_to_url(path: str, normalize_path: bool = True) -> str:
     """
-    Convert a path to a file: URL.  The path will be made absolute and have
-    quoted path parts.
+    Convert a path to a file: URL with quoted path parts. The path will be
+    normalized and made absolute if *normalize_path* is true (the default.)
     """
     if normalize_path:
         path = os.path.abspath(path)
@@ -37,7 +37,7 @@ def url_to_path(url: str) -> str:
     """
     Convert a file: URL to a path.
     """
-    scheme, netloc, path, _, _ = urllib.parse.urlsplit(url)
+    scheme, netloc, path = urllib.parse.urlsplit(url)[:3]
     assert scheme == "file" or scheme.endswith(
         "+file"
     ), f"You can only turn file: urls into filenames (not {url!r})"
@@ -74,16 +74,16 @@ def clean_file_url(url: str) -> str:
     """
     Fix up quoting and leading slashes in the given file: URL.
 
-    e.g. 'file:/c:/foo bar' --> 'file:///c:/foo%20bar'.
+    e.g. 'file:/c:/foo bar@1.0' --> 'file:///c:/foo%20bar@1.0'.
     """
     # Replace "@" characters to protect them from percent-encoding.
-    at_symbol_token = "-_-PIP_AT_SYMBOL_-_"
+    at_symbol_token = "---PIP_AT_SYMBOL---"
     assert at_symbol_token not in url
     url = url.replace("@", at_symbol_token)
     parts = urllib.parse.urlsplit(url)
 
-    # Convert to a file path and back. This normalizes the URL, but removes
-    # the original scheme, query and fragment components.
+    # Convert URL to a file path and back. This normalizes the netloc and
+    # path, but resets the other URL components.
     tidy_url = path_to_url(url_to_path(url), normalize_path=False)
     tidy_parts = urllib.parse.urlsplit(tidy_url)
 
diff --git a/tests/unit/test_collector.py b/tests/unit/test_collector.py
index 6b306c53432..5602d7616fd 100644
--- a/tests/unit/test_collector.py
+++ b/tests/unit/test_collector.py
@@ -358,7 +358,7 @@ def test_clean_url_path(path: str, expected: str) -> None:
         ),
         # URL with Windows drive letter. The `:` after the drive
         # letter should not be quoted. The trailing `/` should be
-        # removed.
+        # retained.
         pytest.param(
             "file:///T:/path/with spaces/",
             "file:///T:/path/with%20spaces/",

From 00b7fa04c10b39799197e771cd90a826a1d31864 Mon Sep 17 00:00:00 2001
From: barneygale <barney.gale@gmail.com>
Date: Thu, 24 Jul 2025 20:18:32 +0100
Subject: [PATCH 15/17] Undo change to `pip._internal.vcs.git` and un-move
 function.

---
 src/pip/_internal/models/link.py | 30 ++++++++++++++++++++++++++++--
 src/pip/_internal/utils/urls.py  | 25 -------------------------
 src/pip/_internal/vcs/git.py     | 19 ++++++++++++++++---
 tests/unit/test_collector.py     | 24 ++++++++++++++++++++++++
 tests/unit/test_urls.py          | 25 +------------------------
 5 files changed, 69 insertions(+), 54 deletions(-)

diff --git a/src/pip/_internal/models/link.py b/src/pip/_internal/models/link.py
index dc18e752a1c..6ef55dc1b27 100644
--- a/src/pip/_internal/models/link.py
+++ b/src/pip/_internal/models/link.py
@@ -24,7 +24,7 @@
     split_auth_from_netloc,
     splitext,
 )
-from pip._internal.utils.urls import clean_file_url, path_to_url, url_to_path
+from pip._internal.utils.urls import path_to_url, url_to_path
 
 if TYPE_CHECKING:
     from pip._internal.index.collector import IndexContent
@@ -121,6 +121,32 @@ def _clean_url_path_part(part: str) -> str:
     return urllib.parse.quote(urllib.parse.unquote(part))
 
 
+def _clean_file_url(url: str) -> str:
+    """
+    Clean a URL that corresponds to a local
+    filesystem path (i.e. the first part after splitting on "@" characters).
+    """
+    # Replace "@" characters to protect them from percent-encoding.
+    at_symbol_token = "---PIP_AT_SYMBOL---"
+    assert at_symbol_token not in url
+    url = url.replace("@", at_symbol_token)
+    parts = urllib.parse.urlsplit(url)
+
+    # We unquote prior to quoting to make sure nothing is double quoted.
+    # Also, on Windows the path part might contain a drive letter which
+    # should not be quoted. On Linux where drive letters do not
+    # exist, the colon should be quoted.
+    tidy_url = path_to_url(url_to_path(url), normalize_path=False)
+    tidy_parts = urllib.parse.urlsplit(tidy_url)
+
+    # Restore the original scheme, query and fragment components.
+    url = urllib.parse.urlunsplit(tidy_parts[:3] + parts[3:])
+    url = url.replace(tidy_parts.scheme, parts.scheme, 1)
+
+    # Restore "@" characters that were replaced earlier.
+    return url.replace(at_symbol_token, "@")
+
+
 # percent-encoded:                   /
 _reserved_chars_re = re.compile("(@|%2F)", re.IGNORECASE)
 
@@ -153,7 +179,7 @@ def _ensure_quoted_url(url: str) -> str:
     result = urllib.parse.urlsplit(url)
     # If the netloc is empty, then the URL refers to a local filesystem path.
     if not result.netloc:
-        return clean_file_url(url)
+        return _clean_file_url(url)
     path = _clean_url_path(result.path)
     return urllib.parse.urlunsplit(result._replace(path=path))
 
diff --git a/src/pip/_internal/utils/urls.py b/src/pip/_internal/utils/urls.py
index 989311c016c..e8f3cb25b5b 100644
--- a/src/pip/_internal/utils/urls.py
+++ b/src/pip/_internal/utils/urls.py
@@ -68,28 +68,3 @@ def url_to_path(url: str) -> str:
     encoding = sys.getfilesystemencoding()
     errors = sys.getfilesystemencodeerrors()
     return urllib.parse.unquote(path, encoding, errors)
-
-
-def clean_file_url(url: str) -> str:
-    """
-    Fix up quoting and leading slashes in the given file: URL.
-
-    e.g. 'file:/c:/foo bar@1.0' --> 'file:///c:/foo%20bar@1.0'.
-    """
-    # Replace "@" characters to protect them from percent-encoding.
-    at_symbol_token = "---PIP_AT_SYMBOL---"
-    assert at_symbol_token not in url
-    url = url.replace("@", at_symbol_token)
-    parts = urllib.parse.urlsplit(url)
-
-    # Convert URL to a file path and back. This normalizes the netloc and
-    # path, but resets the other URL components.
-    tidy_url = path_to_url(url_to_path(url), normalize_path=False)
-    tidy_parts = urllib.parse.urlsplit(tidy_url)
-
-    # Restore the original scheme, query and fragment components.
-    url = urllib.parse.urlunsplit(tidy_parts[:3] + parts[3:])
-    url = url.replace(tidy_parts.scheme, parts.scheme, 1)
-
-    # Restore "@" characters that were replaced earlier.
-    return url.replace(at_symbol_token, "@")
diff --git a/src/pip/_internal/vcs/git.py b/src/pip/_internal/vcs/git.py
index dba49389d77..1769da791cb 100644
--- a/src/pip/_internal/vcs/git.py
+++ b/src/pip/_internal/vcs/git.py
@@ -4,13 +4,14 @@
 import os.path
 import pathlib
 import re
+import urllib.parse
+import urllib.request
 from dataclasses import replace
 from typing import Any
 
 from pip._internal.exceptions import BadCommand, InstallationError
 from pip._internal.utils.misc import HiddenText, display_path, hide_url
 from pip._internal.utils.subprocess import make_command
-from pip._internal.utils.urls import clean_file_url
 from pip._internal.vcs.versioncontrol import (
     AuthInfo,
     RemoteNotFoundError,
@@ -21,6 +22,10 @@
     vcs,
 )
 
+urlsplit = urllib.parse.urlsplit
+urlunsplit = urllib.parse.urlunsplit
+
+
 logger = logging.getLogger(__name__)
 
 
@@ -497,8 +502,16 @@ def get_url_rev_and_auth(cls, url: str) -> tuple[str, str | None, AuthInfo]:
         """
         # Works around an apparent Git bug
         # (see https://article.gmane.org/gmane.comp.version-control.git/146500)
-        if url.startswith("git+file:"):
-            url = clean_file_url(url)
+        scheme, netloc, path, query, fragment = urlsplit(url)
+        if scheme.endswith("file"):
+            initial_slashes = path[: -len(path.lstrip("/"))]
+            newpath = initial_slashes + urllib.request.url2pathname(path).replace(
+                "\\", "/"
+            ).lstrip("/")
+            after_plus = scheme.find("+") + 1
+            url = scheme[:after_plus] + urlunsplit(
+                (scheme[after_plus:], netloc, newpath, query, fragment),
+            )
 
         if "://" not in url:
             assert "file:" not in url
diff --git a/tests/unit/test_collector.py b/tests/unit/test_collector.py
index 5602d7616fd..318e6ef8a81 100644
--- a/tests/unit/test_collector.py
+++ b/tests/unit/test_collector.py
@@ -33,6 +33,7 @@
     Link,
     LinkHash,
     MetadataFile,
+    _clean_file_url,
     _clean_url_path,
     _ensure_quoted_url,
 )
@@ -295,6 +296,29 @@ def test_clean_url_path(path: str, expected: str) -> None:
     assert _clean_url_path(path) == expected
 
 
+@pytest.mark.parametrize(
+    "url, expected",
+    [
+        # Test a VCS path with a Windows drive letter and revision.
+        pytest.param(
+            "file:/T:/with space/repo.git@1.0",
+            "file:///T:/with%20space/repo.git@1.0",
+            marks=pytest.mark.skipif("sys.platform != 'win32'"),
+        ),
+        # Test a VCS path with a Windows drive letter and revision,
+        # running on non-windows platform.
+        pytest.param(
+            "file:/T:/with space/repo.git@1.0",
+            "file:///T%3A/with%20space/repo.git@1.0",
+            marks=pytest.mark.skipif("sys.platform == 'win32'"),
+        ),
+    ],
+)
+def test_clean_file_url(url: str, expected: str) -> None:
+    actual = _clean_file_url(url)
+    assert actual == expected
+
+
 @pytest.mark.parametrize(
     "url, clean_url",
     [
diff --git a/tests/unit/test_urls.py b/tests/unit/test_urls.py
index b88356c0caa..0c145255080 100644
--- a/tests/unit/test_urls.py
+++ b/tests/unit/test_urls.py
@@ -4,7 +4,7 @@
 
 import pytest
 
-from pip._internal.utils.urls import clean_file_url, path_to_url, url_to_path
+from pip._internal.utils.urls import path_to_url, url_to_path
 
 
 @pytest.mark.skipif("sys.platform == 'win32'")
@@ -75,26 +75,3 @@ def test_url_to_path_path_to_url_symmetry_win() -> None:
 
     unc_path = r"\\unc\share\path"
     assert url_to_path(path_to_url(unc_path)) == unc_path
-
-
-@pytest.mark.parametrize(
-    "url, expected",
-    [
-        # Test a VCS path with a Windows drive letter and revision.
-        pytest.param(
-            "file:/T:/with space/repo.git@1.0",
-            "file:///T:/with%20space/repo.git@1.0",
-            marks=pytest.mark.skipif("sys.platform != 'win32'"),
-        ),
-        # Test a VCS path with a Windows drive letter and revision,
-        # running on non-windows platform.
-        pytest.param(
-            "file:/T:/with space/repo.git@1.0",
-            "file:///T%3A/with%20space/repo.git@1.0",
-            marks=pytest.mark.skipif("sys.platform == 'win32'"),
-        ),
-    ],
-)
-def test_clean_file_url(url: str, expected: str) -> None:
-    actual = clean_file_url(url)
-    assert actual == expected

From f30c187f3f5ce28279d01cbd3b360b3b6e26ef21 Mon Sep 17 00:00:00 2001
From: barneygale <barney.gale@gmail.com>
Date: Sun, 27 Jul 2025 21:07:21 +0100
Subject: [PATCH 16/17] Fix lint

---
 src/pip/_internal/models/link.py | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/pip/_internal/models/link.py b/src/pip/_internal/models/link.py
index 4ce42173453..f1bacd7bca1 100644
--- a/src/pip/_internal/models/link.py
+++ b/src/pip/_internal/models/link.py
@@ -6,7 +6,6 @@
 import os
 import posixpath
 import re
-import sys
 import urllib.parse
 from collections.abc import Mapping
 from dataclasses import dataclass

From 1ad7fbebe449e2c81cceffe07eab38328eb591cb Mon Sep 17 00:00:00 2001
From: barneygale <barney.gale@gmail.com>
Date: Sun, 27 Jul 2025 21:07:30 +0100
Subject: [PATCH 17/17] =?UTF-8?q?Revert=20"Enable=20Python=203.14=20CI=20?=
 =?UTF-8?q?=F0=9F=A4=9E"?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

This reverts commit 8c817be90afb972cb77bb51d789ae82f3b6a7cee.
---
 .github/workflows/ci.yml | 2 --
 noxfile.py               | 2 +-
 2 files changed, 1 insertion(+), 3 deletions(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index f3d69fa5763..815617e1c19 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -122,7 +122,6 @@ jobs:
           - "3.11"
           - "3.12"
           - "3.13"
-          - "3.14"
 
     steps:
       - uses: actions/checkout@v4
@@ -182,7 +181,6 @@ jobs:
           # - "3.11"
           # - "3.12"
           - "3.13"
-          - "3.14"
         group:
           - { number: 1, pytest-filter: "not test_install" }
           - { number: 2, pytest-filter: "test_install" }
diff --git a/noxfile.py b/noxfile.py
index 88e9d5dec66..160e823e9f1 100644
--- a/noxfile.py
+++ b/noxfile.py
@@ -67,7 +67,7 @@ def should_update_common_wheels() -> bool:
 # -----------------------------------------------------------------------------
 # Development Commands
 # -----------------------------------------------------------------------------
-@nox.session(python=["3.9", "3.10", "3.11", "3.12", "3.13", "3.14", "pypy3"])
+@nox.session(python=["3.9", "3.10", "3.11", "3.12", "3.13", "pypy3"])
 def test(session: nox.Session) -> None:
     # Get the common wheels.
     if should_update_common_wheels():