From 0ed397a2980d15e47b927689516ada7e34de5c90 Mon Sep 17 00:00:00 2001
From: nineteendo <nineteendo19d0@gmail.com>
Date: Sat, 6 Apr 2024 17:36:01 +0200
Subject: [PATCH 01/16] Remove _get_sep()

---
 Lib/posixpath.py           | 23 +++++++++--------------
 Lib/test/test_posixpath.py |  2 ++
 2 files changed, 11 insertions(+), 14 deletions(-)

diff --git a/Lib/posixpath.py b/Lib/posixpath.py
index 0e8bb5ab10d916..56cbad6bd0895c 100644
--- a/Lib/posixpath.py
+++ b/Lib/posixpath.py
@@ -38,12 +38,6 @@
            "commonpath", "isjunction","isdevdrive"]
 
 
-def _get_sep(path):
-    if isinstance(path, bytes):
-        return b'/'
-    else:
-        return '/'
-
 # Normalize the case of a pathname.  Trivial in Posix, string.lower on Mac.
 # On MS-DOS this may also turn slashes into backslashes; however, other
 # normalizations (such as optimizing '../' away) are not allowed
@@ -60,7 +54,7 @@ def normcase(s):
 def isabs(s):
     """Test whether a path is absolute"""
     s = os.fspath(s)
-    sep = _get_sep(s)
+    sep = b'/' if isinstance(s, bytes) else '/'
     return s.startswith(sep)
 
 
@@ -74,15 +68,15 @@ def join(a, *p):
     will be discarded.  An empty last part will result in a path that
     ends with a separator."""
     a = os.fspath(a)
-    sep = _get_sep(a)
+    sep = b'/' if isinstance(a, bytes) else '/'
     path = a
     try:
         if not p:
             path[:0] + sep  #23780: Ensure compatible data type even if p is null.
         for b in map(os.fspath, p):
-            if b.startswith(sep):
+            if b.startswith(sep) or not path:  # startswith ensures no mixing
                 path = b
-            elif not path or path.endswith(sep):
+            elif path.endswith(sep):
                 path += b
             else:
                 path += sep + b
@@ -101,7 +95,7 @@ def split(p):
     """Split a pathname.  Returns tuple "(head, tail)" where "tail" is
     everything after the final slash.  Either part may be empty."""
     p = os.fspath(p)
-    sep = _get_sep(p)
+    sep = b'/' if isinstance(p, bytes) else '/'
     i = p.rfind(sep) + 1
     head, tail = p[:i], p[i:]
     if head and head != sep*len(head):
@@ -169,7 +163,7 @@ def splitroot(p):
 def basename(p):
     """Returns the final component of a pathname"""
     p = os.fspath(p)
-    sep = _get_sep(p)
+    sep = b'/' if isinstance(p, bytes) else '/'
     i = p.rfind(sep) + 1
     return p[i:]
 
@@ -179,7 +173,7 @@ def basename(p):
 def dirname(p):
     """Returns the directory component of a pathname"""
     p = os.fspath(p)
-    sep = _get_sep(p)
+    sep = b'/' if isinstance(p, bytes) else '/'
     i = p.rfind(sep) + 1
     head = p[:i]
     if head and head != sep*len(head):
@@ -232,11 +226,12 @@ def expanduser(path):
     path = os.fspath(path)
     if isinstance(path, bytes):
         tilde = b'~'
+        sep = b'/'
     else:
         tilde = '~'
+        sep = '/'
     if not path.startswith(tilde):
         return path
-    sep = _get_sep(path)
     i = path.find(sep, 1)
     if i < 0:
         i = len(path)
diff --git a/Lib/test/test_posixpath.py b/Lib/test/test_posixpath.py
index 807f985f7f4df7..932344f1115909 100644
--- a/Lib/test/test_posixpath.py
+++ b/Lib/test/test_posixpath.py
@@ -56,6 +56,8 @@ def test_join(self):
         self.assertEqual(fn(b"/foo", b"bar", b"baz"),          b"/foo/bar/baz")
         self.assertEqual(fn(b"/foo/", b"bar/", b"baz/"),       b"/foo/bar/baz/")
 
+        self.assertEqual(fn("a", ""),          "a/")
+        self.assertEqual(fn("a", "", ""),      "a/")
         self.assertEqual(fn("a", "b"),         "a/b")
         self.assertEqual(fn("a", "b/"),        "a/b/")
         self.assertEqual(fn("a/", "b"),        "a/b")

From 0868dc6d48f3b0bc609259f9b60f0becb8624493 Mon Sep 17 00:00:00 2001
From: nineteendo <nineteendo19d0@gmail.com>
Date: Sat, 6 Apr 2024 18:21:06 +0200
Subject: [PATCH 02/16] Remove type check

---
 Lib/ntpath.py    |  2 --
 Lib/posixpath.py | 15 +++++----------
 2 files changed, 5 insertions(+), 12 deletions(-)

diff --git a/Lib/ntpath.py b/Lib/ntpath.py
index f9f6c78566e8ed..43763bd4aed082 100644
--- a/Lib/ntpath.py
+++ b/Lib/ntpath.py
@@ -108,8 +108,6 @@ def join(path, *paths):
         seps = '\\/'
         colon_seps = ':\\/'
     try:
-        if not paths:
-            path[:0] + sep  #23780: Ensure compatible data type even if p is null.
         result_drive, result_root, result_path = splitroot(path)
         for p in map(os.fspath, paths):
             p_drive, p_root, p_path = splitroot(p)
diff --git a/Lib/posixpath.py b/Lib/posixpath.py
index 56cbad6bd0895c..0a10b3ae0b98f8 100644
--- a/Lib/posixpath.py
+++ b/Lib/posixpath.py
@@ -71,8 +71,6 @@ def join(a, *p):
     sep = b'/' if isinstance(a, bytes) else '/'
     path = a
     try:
-        if not p:
-            path[:0] + sep  #23780: Ensure compatible data type even if p is null.
         for b in map(os.fspath, p):
             if b.startswith(sep) or not path:  # startswith ensures no mixing
                 path = b
@@ -155,7 +153,7 @@ def splitroot(p):
     else:
         # Precisely two leading slashes, e.g.: '//foo'. Implementation defined per POSIX, see
         # https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap04.html#tag_04_13
-        return empty, p[:2], p[2:]
+        return empty, sep + sep, p[2:]
 
 
 # Return the tail (basename) part of a path, same as split(path)[1].
@@ -225,11 +223,11 @@ def expanduser(path):
     do nothing."""
     path = os.fspath(path)
     if isinstance(path, bytes):
-        tilde = b'~'
         sep = b'/'
+        tilde = b'~'
     else:
-        tilde = '~'
         sep = '/'
+        tilde = '~'
     if not path.startswith(tilde):
         return path
     i = path.find(sep, 1)
@@ -271,11 +269,8 @@ def expanduser(path):
         return path
     if isinstance(path, bytes):
         userhome = os.fsencode(userhome)
-        root = b'/'
-    else:
-        root = '/'
-    userhome = userhome.rstrip(root)
-    return (userhome + path[i:]) or root
+    userhome = userhome.rstrip(sep)
+    return (userhome + path[i:]) or sep
 
 
 # Expand paths containing shell variable substitutions.

From a431caa6efabaa2c0962e238ad3341576150d7c2 Mon Sep 17 00:00:00 2001
From: nineteendo <nineteendo19d0@gmail.com>
Date: Sat, 6 Apr 2024 18:37:00 +0200
Subject: [PATCH 03/16] Remove `os.fspath()` call on `curdir`

---
 Lib/ntpath.py | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/Lib/ntpath.py b/Lib/ntpath.py
index 43763bd4aed082..4941f984b48384 100644
--- a/Lib/ntpath.py
+++ b/Lib/ntpath.py
@@ -782,7 +782,11 @@ def realpath(path, *, strict=False):
 
 def relpath(path, start=None):
     """Return a relative version of a path"""
+
     path = os.fspath(path)
+    if not path:
+        raise ValueError("no path specified")
+
     if isinstance(path, bytes):
         sep = b'\\'
         curdir = b'.'
@@ -794,11 +798,9 @@ def relpath(path, start=None):
 
     if start is None:
         start = curdir
+    else:
+        start = os.fspath(start)
 
-    if not path:
-        raise ValueError("no path specified")
-
-    start = os.fspath(start)
     try:
         start_abs = abspath(normpath(start))
         path_abs = abspath(normpath(path))

From 51d93eaba73cd6467ef8890910c27782f06334c4 Mon Sep 17 00:00:00 2001
From: nineteendo <nineteendo19d0@gmail.com>
Date: Sat, 6 Apr 2024 22:37:09 +0200
Subject: [PATCH 04/16] `str.join()`

---
 Lib/ntpath.py    | 2 +-
 Lib/posixpath.py | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/Lib/ntpath.py b/Lib/ntpath.py
index 4941f984b48384..56c226d3c648cf 100644
--- a/Lib/ntpath.py
+++ b/Lib/ntpath.py
@@ -822,7 +822,7 @@ def relpath(path, start=None):
         rel_list = [pardir] * (len(start_list)-i) + path_list[i:]
         if not rel_list:
             return curdir
-        return join(*rel_list)
+        return sep.join(rel_list)
     except (TypeError, ValueError, AttributeError, BytesWarning, DeprecationWarning):
         genericpath._check_arg_types('relpath', path, start)
         raise
diff --git a/Lib/posixpath.py b/Lib/posixpath.py
index 0a10b3ae0b98f8..15d272ea4e8117 100644
--- a/Lib/posixpath.py
+++ b/Lib/posixpath.py
@@ -184,6 +184,7 @@ def dirname(p):
 
 def ismount(path):
     """Test whether a path is a mount point"""
+    path = os.fspath(path)
     try:
         s1 = os.lstat(path)
     except (OSError, ValueError):
@@ -194,7 +195,6 @@ def ismount(path):
         if stat.S_ISLNK(s1.st_mode):
             return False
 
-    path = os.fspath(path)
     if isinstance(path, bytes):
         parent = join(path, b'..')
     else:
@@ -519,7 +519,7 @@ def relpath(path, start=None):
         rel_list = [pardir] * (len(start_list)-i) + path_list[i:]
         if not rel_list:
             return curdir
-        return join(*rel_list)
+        return sep.join(rel_list)
     except (TypeError, AttributeError, BytesWarning, DeprecationWarning):
         genericpath._check_arg_types('relpath', path, start)
         raise

From a64e87b6c07eecda6ac9f3af6082755dd4f9b7b9 Mon Sep 17 00:00:00 2001
From: nineteendo <nineteendo19d0@gmail.com>
Date: Sun, 7 Apr 2024 08:00:24 +0200
Subject: [PATCH 05/16] simplify split

---
 Lib/ntpath.py    | 4 ++--
 Lib/posixpath.py | 6 ++++--
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/Lib/ntpath.py b/Lib/ntpath.py
index 56c226d3c648cf..03210587cb820e 100644
--- a/Lib/ntpath.py
+++ b/Lib/ntpath.py
@@ -810,8 +810,8 @@ def relpath(path, start=None):
             raise ValueError("path is on mount %r, start on mount %r" % (
                 path_drive, start_drive))
 
-        start_list = [x for x in start_rest.split(sep) if x]
-        path_list = [x for x in path_rest.split(sep) if x]
+        start_list = start_rest.split(sep) if start_rest else []
+        path_list = path_rest.split(sep) if path_rest else []
         # Work out how much of the filepath is shared by start and path.
         i = 0
         for e1, e2 in zip(start_list, path_list):
diff --git a/Lib/posixpath.py b/Lib/posixpath.py
index 15d272ea4e8117..a1d3c040204b3c 100644
--- a/Lib/posixpath.py
+++ b/Lib/posixpath.py
@@ -511,8 +511,10 @@ def relpath(path, start=None):
         start = os.fspath(start)
 
     try:
-        start_list = [x for x in abspath(start).split(sep) if x]
-        path_list = [x for x in abspath(path).split(sep) if x]
+        start_rest = abspath(start).lstrip(sep)
+        path_rest = abspath(path).lstrip(sep)
+        start_list = start_rest.split(sep) if start_rest else []
+        path_list = path_rest.split(sep) if path_rest else []
         # Work out how much of the filepath is shared by start and path.
         i = len(commonprefix([start_list, path_list]))
 

From 906fecb8be1471b201d481ea9bae1c372464223b Mon Sep 17 00:00:00 2001
From: nineteendo <nineteendo19d0@gmail.com>
Date: Sun, 7 Apr 2024 14:08:49 +0200
Subject: [PATCH 06/16] don't normalise cwd

---
 Lib/ntpath.py    |  6 ++++--
 Lib/posixpath.py | 14 +++++++++-----
 2 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/Lib/ntpath.py b/Lib/ntpath.py
index 03210587cb820e..cae46646211f9e 100644
--- a/Lib/ntpath.py
+++ b/Lib/ntpath.py
@@ -791,10 +791,12 @@ def relpath(path, start=None):
         sep = b'\\'
         curdir = b'.'
         pardir = b'..'
+        getcwd = os.getcwdb
     else:
         sep = '\\'
         curdir = '.'
         pardir = '..'
+        getcwd = os.getcwd
 
     if start is None:
         start = curdir
@@ -802,8 +804,8 @@ def relpath(path, start=None):
         start = os.fspath(start)
 
     try:
-        start_abs = abspath(normpath(start))
-        path_abs = abspath(normpath(path))
+        start_abs = getcwd() if not start or start == curdir else abspath(start)
+        path_abs = abspath(path)
         start_drive, _, start_rest = splitroot(start_abs)
         path_drive, _, path_rest = splitroot(path_abs)
         if normcase(start_drive) != normcase(path_drive):
diff --git a/Lib/posixpath.py b/Lib/posixpath.py
index 62b54f461168cd..59718ed110f864 100644
--- a/Lib/posixpath.py
+++ b/Lib/posixpath.py
@@ -348,7 +348,7 @@ def normpath(path):
             sep = '/'
             dot = '.'
             dotdot = '..'
-        if not path:
+        if not path or path == dot:
             return dot
         _, initial_slashes, path = splitroot(path)
         comps = path.split(sep)
@@ -500,10 +500,12 @@ def relpath(path, start=None):
         curdir = b'.'
         sep = b'/'
         pardir = b'..'
+        getcwd = os.getcwdb
     else:
         curdir = '.'
         sep = '/'
         pardir = '..'
+        getcwd = os.getcwd
 
     if start is None:
         start = curdir
@@ -511,10 +513,12 @@ def relpath(path, start=None):
         start = os.fspath(start)
 
     try:
-        start_rest = abspath(start).lstrip(sep)
-        path_rest = abspath(path).lstrip(sep)
-        start_list = start_rest.split(sep) if start_rest else []
-        path_list = path_rest.split(sep) if path_rest else []
+        start_abs = getcwd() if not start or start == curdir else abspath(start)
+        path_abs = abspath(path)
+        start_tail = start_abs.lstrip(sep)
+        path_tail = path_abs.lstrip(sep)
+        start_list = start_tail.split(sep) if start_tail else []
+        path_list = path_tail.split(sep) if path_tail else []
         # Work out how much of the filepath is shared by start and path.
         i = len(commonprefix([start_list, path_list]))
 

From bd30c3c4436131064b6c1ff16abff06a44c52faa Mon Sep 17 00:00:00 2001
From: nineteendo <nineteendo19d0@gmail.com>
Date: Sun, 7 Apr 2024 14:22:49 +0200
Subject: [PATCH 07/16] clean up mix check

---
 Lib/posixpath.py | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/Lib/posixpath.py b/Lib/posixpath.py
index 59718ed110f864..250b2d22d6ebef 100644
--- a/Lib/posixpath.py
+++ b/Lib/posixpath.py
@@ -554,10 +554,8 @@ def commonpath(paths):
     try:
         split_paths = [path.split(sep) for path in paths]
 
-        try:
-            isabs, = set(p[:1] == sep for p in paths)
-        except ValueError:
-            raise ValueError("Can't mix absolute and relative paths") from None
+        if len({p.startswith(sep) for p in paths}) != 1:
+            raise ValueError("Can't mix absolute and relative paths")
 
         split_paths = [[c for c in s if c and c != curdir] for s in split_paths]
         s1 = min(split_paths)
@@ -568,7 +566,7 @@ def commonpath(paths):
                 common = s1[:i]
                 break
 
-        prefix = sep if isabs else sep[:0]
+        prefix = sep if paths[0].startswith(sep) else sep[:0]
         return prefix + sep.join(common)
     except (TypeError, AttributeError):
         genericpath._check_arg_types('commonpath', *paths)

From 07b1bd3b24986841599f82d34afa7d53367de859 Mon Sep 17 00:00:00 2001
From: nineteendo <nineteendo19d0@gmail.com>
Date: Sun, 7 Apr 2024 14:44:47 +0200
Subject: [PATCH 08/16] remove `_get_bothseps`

---
 Lib/ntpath.py | 20 +++++++++-----------
 1 file changed, 9 insertions(+), 11 deletions(-)

diff --git a/Lib/ntpath.py b/Lib/ntpath.py
index cae46646211f9e..719354709091b1 100644
--- a/Lib/ntpath.py
+++ b/Lib/ntpath.py
@@ -32,12 +32,6 @@
            "samefile", "sameopenfile", "samestat", "commonpath", "isjunction",
            "isdevdrive"]
 
-def _get_bothseps(path):
-    if isinstance(path, bytes):
-        return b'\\/'
-    else:
-        return '\\/'
-
 # Normalize the case of a pathname and map slashes to backslashes.
 # Other normalizations (such as optimizing '../' away) are not done
 # (this is done by normpath).
@@ -230,7 +224,7 @@ def split(p):
     Return tuple (head, tail) where tail is everything after the final slash.
     Either part may be empty."""
     p = os.fspath(p)
-    seps = _get_bothseps(p)
+    seps = b'\\/' if isinstance(p, bytes) else '\\/'
     d, r, p = splitroot(p)
     # set i to index beyond p's last slash
     i = len(p)
@@ -301,7 +295,7 @@ def ismount(path):
     """Test whether a path is a mount point (a drive root, the root of a
     share, or a mounted volume)"""
     path = os.fspath(path)
-    seps = _get_bothseps(path)
+    seps = b'\\/' if isinstance(path, bytes) else '\\/'
     path = abspath(path)
     drive, root, rest = splitroot(path)
     if drive and drive[0] in seps:
@@ -366,13 +360,15 @@ def expanduser(path):
     If user or $HOME is unknown, do nothing."""
     path = os.fspath(path)
     if isinstance(path, bytes):
+        seps = b'\\/'
         tilde = b'~'
     else:
+        seps = '\\/'
         tilde = '~'
     if not path.startswith(tilde):
         return path
     i, n = 1, len(path)
-    while i < n and path[i] not in _get_bothseps(path):
+    while i < n and path[i] not in seps:
         i += 1
 
     if 'USERPROFILE' in os.environ:
@@ -433,6 +429,7 @@ def expandvars(path):
         brace = b'{'
         rbrace = b'}'
         dollar = b'$'
+        empty = b''
         environ = getattr(os, 'environb', None)
     else:
         if '$' not in path and '%' not in path:
@@ -444,8 +441,9 @@ def expandvars(path):
         brace = '{'
         rbrace = '}'
         dollar = '$'
+        empty = ''
         environ = os.environ
-    res = path[:0]
+    res = empty
     index = 0
     pathlen = len(path)
     while index < pathlen:
@@ -504,7 +502,7 @@ def expandvars(path):
                         value = dollar + brace + var + rbrace
                     res += value
             else:
-                var = path[:0]
+                var = empty
                 index += 1
                 c = path[index:index + 1]
                 while c and c in varchars:

From c2d73f6f9f2ebd78a6025c6dda9a086162978d22 Mon Sep 17 00:00:00 2001
From: nineteendo <nineteendo19d0@gmail.com>
Date: Sun, 7 Apr 2024 16:36:16 +0200
Subject: [PATCH 09/16] speedup `realpath()` for relative paths

---
 Lib/ntpath.py    | 10 +++++++---
 Lib/posixpath.py | 14 ++++++++++----
 2 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/Lib/ntpath.py b/Lib/ntpath.py
index 719354709091b1..c1a79de4d86ecb 100644
--- a/Lib/ntpath.py
+++ b/Lib/ntpath.py
@@ -587,9 +587,13 @@ def _abspath_fallback(path):
     path = os.fspath(path)
     if not isabs(path):
         if isinstance(path, bytes):
+            curdir = b'.'
             cwd = os.getcwdb()
         else:
+            curdir = '.'
             cwd = os.getcwd()
+        if not path or path == curdir:
+            return cwd
         path = join(cwd, path)
     return normpath(path)
 
@@ -716,7 +720,7 @@ def realpath(path, *, strict=False):
             prefix = b'\\\\?\\'
             unc_prefix = b'\\\\?\\UNC\\'
             new_unc_prefix = b'\\\\'
-            cwd = os.getcwdb()
+            getcwd = os.getcwdb
             # bpo-38081: Special case for realpath(b'nul')
             devnull = b'nul'
             if normcase(path) == devnull:
@@ -725,14 +729,14 @@ def realpath(path, *, strict=False):
             prefix = '\\\\?\\'
             unc_prefix = '\\\\?\\UNC\\'
             new_unc_prefix = '\\\\'
-            cwd = os.getcwd()
+            getcwd = os.getcwd
             # bpo-38081: Special case for realpath('nul')
             devnull = 'nul'
             if normcase(path) == devnull:
                 return '\\\\.\\NUL'
         had_prefix = path.startswith(prefix)
         if not had_prefix and not isabs(path):
-            path = join(cwd, path)
+            path = join(getcwd(), path)
         try:
             path = _getfinalpathname(path)
             initial_winerror = 0
diff --git a/Lib/posixpath.py b/Lib/posixpath.py
index 250b2d22d6ebef..b3ca2acae4c4fc 100644
--- a/Lib/posixpath.py
+++ b/Lib/posixpath.py
@@ -378,11 +378,17 @@ def abspath(path):
     """Return an absolute path."""
     path = os.fspath(path)
     if isinstance(path, bytes):
-        if not path.startswith(b'/'):
-            path = join(os.getcwdb(), path)
+        sep = b'/'
+        curdir = b'.'
+        getcwd = os.getcwdb
     else:
-        if not path.startswith('/'):
-            path = join(os.getcwd(), path)
+        sep = '/'
+        curdir = '.'
+        getcwd = os.getcwd
+    if not path.startswith(sep):
+        if not path or path == curdir:
+            return getcwd()
+        path = join(getcwd(), path)
     return normpath(path)
 
 

From 62c7b972dd9cbbefc1f311e803689108c8da722f Mon Sep 17 00:00:00 2001
From: nineteendo <nineteendo19d0@gmail.com>
Date: Sun, 7 Apr 2024 16:56:20 +0200
Subject: [PATCH 10/16] save `normcase(path)` in variable

---
 Lib/ntpath.py | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/Lib/ntpath.py b/Lib/ntpath.py
index c1a79de4d86ecb..40da83cf18bea1 100644
--- a/Lib/ntpath.py
+++ b/Lib/ntpath.py
@@ -563,10 +563,8 @@ def normpath(path):
                     i += 1
             else:
                 i += 1
-        # If the path is now empty, substitute '.'
-        if not prefix and not comps:
-            comps.append(curdir)
-        return prefix + sep.join(comps)
+        path = prefix + sep.join(comps)
+        return path or curdir
 
 else:
     def normpath(path):
@@ -636,8 +634,9 @@ def _readlink_deep(path):
         allowed_winerror = 1, 2, 3, 5, 21, 32, 50, 67, 87, 4390, 4392, 4393
 
         seen = set()
-        while normcase(path) not in seen:
-            seen.add(normcase(path))
+        normp = normcase(path)
+        while normp not in seen:
+            seen.add(normp)
             try:
                 old_path = path
                 path = _nt_readlink(path)
@@ -651,6 +650,7 @@ def _readlink_deep(path):
                         path = old_path
                         break
                     path = normpath(join(dirname(old_path), path))
+                    normp = normcase(path)
             except OSError as ex:
                 if ex.winerror in allowed_winerror:
                     break

From 6dfe0886b2fda79ffe6da5516d7b337462aa6ab0 Mon Sep 17 00:00:00 2001
From: nineteendo <nineteendo19d0@gmail.com>
Date: Sun, 7 Apr 2024 19:05:03 +0200
Subject: [PATCH 11/16] Remove newline

---
 Lib/ntpath.py | 1 -
 1 file changed, 1 deletion(-)

diff --git a/Lib/ntpath.py b/Lib/ntpath.py
index 40da83cf18bea1..f9885f69267391 100644
--- a/Lib/ntpath.py
+++ b/Lib/ntpath.py
@@ -784,7 +784,6 @@ def realpath(path, *, strict=False):
 
 def relpath(path, start=None):
     """Return a relative version of a path"""
-
     path = os.fspath(path)
     if not path:
         raise ValueError("no path specified")

From d968aa010ea4a59349e4c7e50ca71ece92c3e7c1 Mon Sep 17 00:00:00 2001
From: nineteendo <nineteendo19d0@gmail.com>
Date: Sun, 7 Apr 2024 19:16:42 +0200
Subject: [PATCH 12/16] remove empty slice

---
 Lib/posixpath.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/Lib/posixpath.py b/Lib/posixpath.py
index b3ca2acae4c4fc..7ac5e2a26aab37 100644
--- a/Lib/posixpath.py
+++ b/Lib/posixpath.py
@@ -553,9 +553,11 @@ def commonpath(paths):
     if isinstance(paths[0], bytes):
         sep = b'/'
         curdir = b'.'
+        empty = b''
     else:
         sep = '/'
         curdir = '.'
+        empty = ''
 
     try:
         split_paths = [path.split(sep) for path in paths]
@@ -572,7 +574,7 @@ def commonpath(paths):
                 common = s1[:i]
                 break
 
-        prefix = sep if paths[0].startswith(sep) else sep[:0]
+        prefix = sep if paths[0].startswith(sep) else empty
         return prefix + sep.join(common)
     except (TypeError, AttributeError):
         genericpath._check_arg_types('commonpath', *paths)

From da7e437d64aa1679dbedd7f8242491f45c711053 Mon Sep 17 00:00:00 2001
From: nineteendo <nineteendo19d0@gmail.com>
Date: Sun, 7 Apr 2024 20:46:04 +0200
Subject: [PATCH 13/16] Revert `relpath()`

---
 Lib/ntpath.py    | 21 +++++++++------------
 Lib/posixpath.py | 12 +++---------
 2 files changed, 12 insertions(+), 21 deletions(-)

diff --git a/Lib/ntpath.py b/Lib/ntpath.py
index f9885f69267391..70bcb3d6e414eb 100644
--- a/Lib/ntpath.py
+++ b/Lib/ntpath.py
@@ -785,36 +785,33 @@ def realpath(path, *, strict=False):
 def relpath(path, start=None):
     """Return a relative version of a path"""
     path = os.fspath(path)
-    if not path:
-        raise ValueError("no path specified")
-
     if isinstance(path, bytes):
         sep = b'\\'
         curdir = b'.'
         pardir = b'..'
-        getcwd = os.getcwdb
     else:
         sep = '\\'
         curdir = '.'
         pardir = '..'
-        getcwd = os.getcwd
 
     if start is None:
         start = curdir
-    else:
-        start = os.fspath(start)
 
+    if not path:
+        raise ValueError("no path specified")
+
+    start = os.fspath(start)
     try:
-        start_abs = getcwd() if not start or start == curdir else abspath(start)
-        path_abs = abspath(path)
+        start_abs = abspath(normpath(start))
+        path_abs = abspath(normpath(path))
         start_drive, _, start_rest = splitroot(start_abs)
         path_drive, _, path_rest = splitroot(path_abs)
         if normcase(start_drive) != normcase(path_drive):
             raise ValueError("path is on mount %r, start on mount %r" % (
                 path_drive, start_drive))
 
-        start_list = start_rest.split(sep) if start_rest else []
-        path_list = path_rest.split(sep) if path_rest else []
+        start_list = [x for x in start_rest.split(sep) if x]
+        path_list = [x for x in path_rest.split(sep) if x]
         # Work out how much of the filepath is shared by start and path.
         i = 0
         for e1, e2 in zip(start_list, path_list):
@@ -825,7 +822,7 @@ def relpath(path, start=None):
         rel_list = [pardir] * (len(start_list)-i) + path_list[i:]
         if not rel_list:
             return curdir
-        return sep.join(rel_list)
+        return join(*rel_list)
     except (TypeError, ValueError, AttributeError, BytesWarning, DeprecationWarning):
         genericpath._check_arg_types('relpath', path, start)
         raise
diff --git a/Lib/posixpath.py b/Lib/posixpath.py
index 7ac5e2a26aab37..29dc8e04a02471 100644
--- a/Lib/posixpath.py
+++ b/Lib/posixpath.py
@@ -506,12 +506,10 @@ def relpath(path, start=None):
         curdir = b'.'
         sep = b'/'
         pardir = b'..'
-        getcwd = os.getcwdb
     else:
         curdir = '.'
         sep = '/'
         pardir = '..'
-        getcwd = os.getcwd
 
     if start is None:
         start = curdir
@@ -519,19 +517,15 @@ def relpath(path, start=None):
         start = os.fspath(start)
 
     try:
-        start_abs = getcwd() if not start or start == curdir else abspath(start)
-        path_abs = abspath(path)
-        start_tail = start_abs.lstrip(sep)
-        path_tail = path_abs.lstrip(sep)
-        start_list = start_tail.split(sep) if start_tail else []
-        path_list = path_tail.split(sep) if path_tail else []
+        start_list = [x for x in abspath(start).split(sep) if x]
+        path_list = [x for x in abspath(path).split(sep) if x]
         # Work out how much of the filepath is shared by start and path.
         i = len(commonprefix([start_list, path_list]))
 
         rel_list = [pardir] * (len(start_list)-i) + path_list[i:]
         if not rel_list:
             return curdir
-        return sep.join(rel_list)
+        return join(*rel_list)
     except (TypeError, AttributeError, BytesWarning, DeprecationWarning):
         genericpath._check_arg_types('relpath', path, start)
         raise

From 11fcb2fc928b0dd19848b3370764326892c0c5e1 Mon Sep 17 00:00:00 2001
From: "blurb-it[bot]" <43283697+blurb-it[bot]@users.noreply.github.com>
Date: Sun, 7 Apr 2024 19:03:54 +0000
Subject: [PATCH 14/16] =?UTF-8?q?=F0=9F=93=9C=F0=9F=A4=96=20Added=20by=20b?=
 =?UTF-8?q?lurb=5Fit.?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../2024-04-07-19-03-53.gh-issue-117609.J-C6J2.rst               | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 Misc/NEWS.d/next/Core and Builtins/2024-04-07-19-03-53.gh-issue-117609.J-C6J2.rst

diff --git a/Misc/NEWS.d/next/Core and Builtins/2024-04-07-19-03-53.gh-issue-117609.J-C6J2.rst b/Misc/NEWS.d/next/Core and Builtins/2024-04-07-19-03-53.gh-issue-117609.J-C6J2.rst
new file mode 100644
index 00000000000000..7932a390ac150a
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2024-04-07-19-03-53.gh-issue-117609.J-C6J2.rst	
@@ -0,0 +1 @@
+Speedup some functions in :mod:`os.path`.

From 5f7025f5c68a0c19f0e5015c636277b53e1826ed Mon Sep 17 00:00:00 2001
From: nineteendo <nineteendo19d0@gmail.com>
Date: Mon, 8 Apr 2024 10:49:33 +0200
Subject: [PATCH 15/16] Fix tests

---
 Lib/ntpath.py | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/Lib/ntpath.py b/Lib/ntpath.py
index 70bcb3d6e414eb..f753ffaa71d0bd 100644
--- a/Lib/ntpath.py
+++ b/Lib/ntpath.py
@@ -585,13 +585,9 @@ def _abspath_fallback(path):
     path = os.fspath(path)
     if not isabs(path):
         if isinstance(path, bytes):
-            curdir = b'.'
             cwd = os.getcwdb()
         else:
-            curdir = '.'
             cwd = os.getcwd()
-        if not path or path == curdir:
-            return cwd
         path = join(cwd, path)
     return normpath(path)
 
@@ -650,7 +646,7 @@ def _readlink_deep(path):
                         path = old_path
                         break
                     path = normpath(join(dirname(old_path), path))
-                    normp = normcase(path)
+                normp = normcase(path)
             except OSError as ex:
                 if ex.winerror in allowed_winerror:
                     break

From d9680f011a70d1721f90b4122e17b19d3823bd1a Mon Sep 17 00:00:00 2001
From: nineteendo <nineteendo19d0@gmail.com>
Date: Mon, 8 Apr 2024 11:43:34 +0200
Subject: [PATCH 16/16] Revert empty slices

---
 Lib/ntpath.py    | 6 ++----
 Lib/posixpath.py | 4 +---
 2 files changed, 3 insertions(+), 7 deletions(-)

diff --git a/Lib/ntpath.py b/Lib/ntpath.py
index f753ffaa71d0bd..a8fa245857a7e3 100644
--- a/Lib/ntpath.py
+++ b/Lib/ntpath.py
@@ -429,7 +429,6 @@ def expandvars(path):
         brace = b'{'
         rbrace = b'}'
         dollar = b'$'
-        empty = b''
         environ = getattr(os, 'environb', None)
     else:
         if '$' not in path and '%' not in path:
@@ -441,9 +440,8 @@ def expandvars(path):
         brace = '{'
         rbrace = '}'
         dollar = '$'
-        empty = ''
         environ = os.environ
-    res = empty
+    res = path[:0]
     index = 0
     pathlen = len(path)
     while index < pathlen:
@@ -502,7 +500,7 @@ def expandvars(path):
                         value = dollar + brace + var + rbrace
                     res += value
             else:
-                var = empty
+                var = path[:0]
                 index += 1
                 c = path[index:index + 1]
                 while c and c in varchars:
diff --git a/Lib/posixpath.py b/Lib/posixpath.py
index 29dc8e04a02471..07073f26c94f09 100644
--- a/Lib/posixpath.py
+++ b/Lib/posixpath.py
@@ -547,11 +547,9 @@ def commonpath(paths):
     if isinstance(paths[0], bytes):
         sep = b'/'
         curdir = b'.'
-        empty = b''
     else:
         sep = '/'
         curdir = '.'
-        empty = ''
 
     try:
         split_paths = [path.split(sep) for path in paths]
@@ -568,7 +566,7 @@ def commonpath(paths):
                 common = s1[:i]
                 break
 
-        prefix = sep if paths[0].startswith(sep) else empty
+        prefix = sep if paths[0].startswith(sep) else sep[:0]
         return prefix + sep.join(common)
     except (TypeError, AttributeError):
         genericpath._check_arg_types('commonpath', *paths)