gh-85681: Make ntpath.abspath() platform independent

Lib/ntpath.py

@@ -516,6 +516,26 @@ def normpath(path):
  from nt import _getfullpathname
 
 except ImportError: # not running on Windows - mock up something sensible
+ def _strip_dots_and_spaces(path):
+ # As the Windows path normalization does.
+ if isinstance(path, bytes):
+ sep = b'\\'
+ dot = b'.'
+ dots_and_spaces = b'. '
+ else:
+ sep = '\\'
+ dot = '.'
+ dots_and_spaces = '. '
+ drive, root, tail = splitroot(path)
+ if not tail:
+ return path
+ comps = tail.split(sep)
+ for i, comp in enumerate(comps[:-1]):
+ if len(comp) > 1 and comp.endswith(dot) and not comp.endswith(dot*2):
+ comps[i] = comp[:-1]
+ comps[-1] = comps[-1].rstrip(dots_and_spaces)
+ return drive + root + sep.join(comps)
+
  def abspath(path):
  """Return the absolute version of a path."""
  path = os.fspath(path)
@@ -525,7 +545,7 @@ def abspath(path):
  else:
  cwd = os.getcwd()
  path = join(cwd, path)
- return normpath(path)
+ return _strip_dots_and_spaces(normpath(path))
 
 else: # use native Windows method on Windows
  def abspath(path):

Lib/test/test_ntpath.py

@@ -1210,6 +1210,35 @@ def test_expanduser(self):
 
 
 
+ def test_abspath_dots_and_spaces(self):
+ # gh-85681: trailing dots and spaces are stripped from the last
+ # component, and a single trailing dot from other components.
+ tester('ntpath.abspath("C:/spam. . .")', "C:\\spam")
+ tester('ntpath.abspath("C:/spam.")', "C:\\spam")
+ tester('ntpath.abspath("C:/spam ")', "C:\\spam")
+ tester('ntpath.abspath("C:/spam..")', "C:\\spam")
+ tester('ntpath.abspath("C:/.spam")', "C:\\.spam")
+ tester('ntpath.abspath("C:/spam./eggs")', "C:\\spam\\eggs")
+ tester('ntpath.abspath("C:/spam.b./eggs")', "C:\\spam.b\\eggs")
+ tester('ntpath.abspath("C:/spam ./eggs")', "C:\\spam \\eggs")
+ # A trailing dot preceded by a dot is not stripped.
+ tester('ntpath.abspath("C:/spam../eggs")', "C:\\spam..\\eggs")
+ tester('ntpath.abspath("C:/spam.../eggs")', "C:\\spam...\\eggs")
+ # Trailing dots and spaces are stripped even in extended paths.
+ tester('ntpath.abspath("\\\\?\\C:/spam. . .")', "\\\\?\\C:\\spam")
+ tester('ntpath.abspath("\\\\.\\C:/spam. . .")', "\\\\.\\C:\\spam")
+ tester('ntpath.abspath("//server/share/spam. ")',
+ "\\\\server\\share\\spam")
+
+ def test_relpath_dots_and_spaces(self):
+ # gh-85681: relpath() is based on abspath().
+ tester('ntpath.relpath("foo ", "foo")', ".")
+ tester('ntpath.relpath("foo.", "foo")', ".")
+ tester('ntpath.relpath("foo/bar ", "foo")', "bar")
+ tester('ntpath.relpath("foo/bar.", "foo")', "bar")
+ # "foo.." denotes "foo" as the last component, but not as other.
+ tester('ntpath.relpath("foo../bar", "foo..")', "..\\foo..\\bar")
+
  @unittest.skipUnless(nt, "abspath requires 'nt' module")
  def test_abspath(self):
  tester('ntpath.abspath("C:\\")', "C:\\")

Misc/NEWS.d/next/Library/2026-08-08-23-30-00.gh-issue-85681.ntabs.rst

@@ -0,0 +1,3 @@
+:func:`ntpath.abspath` on non-Windows platforms now strips trailing dots and
+spaces like the Windows path normalization does. This makes
+:func:`ntpath.relpath` and other functions based on it platform independent.