[3.13] GH-126212: Fix removal of slashes in file URIs on Windows (GH-126214)

Lib/nturl2path.py

@@ -24,23 +24,15 @@ def url2pathname(url):
             # convert this to \\host\path\on\remote\host
             # (notice halving of slashes at the start of the path)
             url = url[2:]
-        components = url.split('/')
         # make sure not to convert quoted slashes :-)
-        return urllib.parse.unquote('\\'.join(components))
+        return urllib.parse.unquote(url.replace('/', '\\'))
     comp = url.split('|')
     if len(comp) != 2 or comp[0][-1] not in string.ascii_letters:
         error = 'Bad URL: ' + url
         raise OSError(error)
     drive = comp[0][-1].upper()
-    components = comp[1].split('/')
-    path = drive + ':'
-    for comp in components:
-        if comp:
-            path = path + '\\' + urllib.parse.unquote(comp)
-    # Issue #11474 - handing url such as |c/|
-    if path.endswith(':') and url.endswith('/'):
-        path += '\\'
-    return path
+    tail = urllib.parse.unquote(comp[1].replace('/', '\\'))
+    return drive + ':' + tail
 
 def pathname2url(p):
     """OS-specific conversion from a file system path to a relative URL
@@ -60,17 +52,12 @@ def pathname2url(p):
             raise OSError('Bad path: ' + p)
     if not ':' in p:
         # No drive specifier, just convert slashes and quote the name
-        components = p.split('\\')
-        return urllib.parse.quote('/'.join(components))
+        return urllib.parse.quote(p.replace('\\', '/'))
     comp = p.split(':', maxsplit=2)
     if len(comp) != 2 or len(comp[0]) > 1:
         error = 'Bad path: ' + p
         raise OSError(error)
 
     drive = urllib.parse.quote(comp[0].upper())
-    components = comp[1].split('\\')
-    path = '///' + drive + ':'
-    for comp in components:
-        if comp:
-            path = path + '/' + urllib.parse.quote(comp)
-    return path
+    tail = urllib.parse.quote(comp[1].replace('\\', '/'))
+    return '///' + drive + ':' + tail

Lib/test/test_urllib.py

@@ -1526,8 +1526,10 @@ def test_pathname2url_win(self):
         self.assertEqual(fn('\\\\?\\C:\\dir'), '///C:/dir')
         self.assertEqual(fn('\\\\?\\unc\\server\\share\\dir'), '//server/share/dir')
         self.assertEqual(fn("C:"), '///C:')
-        self.assertEqual(fn("C:\\"), '///C:')
+        self.assertEqual(fn("C:\\"), '///C:/')
         self.assertEqual(fn('C:\\a\\b.c'), '///C:/a/b.c')
+        self.assertEqual(fn('C:\\a\\b.c\\'), '///C:/a/b.c/')
+        self.assertEqual(fn('C:\\a\\\\b.c'), '///C:/a//b.c')
         self.assertEqual(fn('C:\\a\\b%#c'), '///C:/a/b%25%23c')
         self.assertEqual(fn('C:\\a\\b\xe9'), '///C:/a/b%C3%A9')
         self.assertEqual(fn('C:\\foo\\bar\\spam.foo'), "///C:/foo/bar/spam.foo")
@@ -1563,13 +1565,15 @@ def test_url2pathname_win(self):
         self.assertEqual(fn("///C|"), 'C:')
         self.assertEqual(fn("///C:"), 'C:')
         self.assertEqual(fn('///C:/'), 'C:\\')
-        self.assertEqual(fn('/C|//'), 'C:\\')
+        self.assertEqual(fn('/C|//'), 'C:\\\\')
         self.assertEqual(fn('///C|/path'), 'C:\\path')
         # No DOS drive
         self.assertEqual(fn("///C/test/"), '\\\\\\C\\test\\')
         self.assertEqual(fn("////C/test/"), '\\\\C\\test\\')
         # DOS drive paths
         self.assertEqual(fn('C:/path/to/file'), 'C:\\path\\to\\file')
+        self.assertEqual(fn('C:/path/to/file/'), 'C:\\path\\to\\file\\')
+        self.assertEqual(fn('C:/path/to//file'), 'C:\\path\\to\\\\file')
         self.assertEqual(fn('C|/path/to/file'), 'C:\\path\\to\\file')
         self.assertEqual(fn('/C|/path/to/file'), 'C:\\path\\to\\file')
         self.assertEqual(fn('///C|/path/to/file'), 'C:\\path\\to\\file')
@@ -1583,6 +1587,9 @@ def test_url2pathname_win(self):
         # Localhost paths
         self.assertEqual(fn('//localhost/C:/path/to/file'), 'C:\\path\\to\\file')
         self.assertEqual(fn('//localhost/C|/path/to/file'), 'C:\\path\\to\\file')
+        # Percent-encoded forward slashes are preserved for backwards compatibility
+        self.assertEqual(fn('C:/foo%2fbar'), 'C:\\foo/bar')
+        self.assertEqual(fn('//server/share/foo%2fbar'), '\\\\server\\share\\foo/bar')
         # Round-tripping
         paths = ['C:',
                  r'\\\C\test\\',

Misc/NEWS.d/next/Library/2024-10-30-23-59-36.gh-issue-126212._9uYjT.rst

@@ -0,0 +1,3 @@
+Fix issue where :func:`urllib.request.pathname2url` and
+:func:`~urllib.request.url2pathname` removed slashes from Windows DOS drive
+paths and URLs.