Revert relpath()

nineteendo · Apr 6, 2024 · Apr 6, 2024 · Apr 6, 2024 · Apr 6, 2024 · Apr 7, 2024
commit da7e437d64aa1679dbedd7f8242491f45c711053
diff --git 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
@@ -506,32 +506,26 @@ 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
     else:
         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