gh-67693: Fix urlunparse() and urlunsplit() for URIs with path starting with multiple slashes and no authority

Lib/test/test_urlparse.py

@@ -103,15 +103,17 @@
 
 class UrlParseTestCase(unittest.TestCase):
 
- def checkRoundtrips(self, url, parsed, split):
+ def checkRoundtrips(self, url, parsed, split, url2=None):
+ if url2 is None:
+ url2 = url
  result = urllib.parse.urlparse(url)
  self.assertSequenceEqual(result, parsed)
  t = (result.scheme, result.netloc, result.path,
  result.params, result.query, result.fragment)
  self.assertSequenceEqual(t, parsed)
  # put it back together and it should be the same
  result2 = urllib.parse.urlunparse(result)
- self.assertSequenceEqual(result2, url)
+ self.assertSequenceEqual(result2, url2)
  self.assertSequenceEqual(result2, result.geturl())
 
  # the result of geturl() is a fixpoint; we can always parse it
@@ -137,7 +139,7 @@ def checkRoundtrips(self, url, parsed, split):
  result.query, result.fragment)
  self.assertSequenceEqual(t, split)
  result2 = urllib.parse.urlunsplit(result)
- self.assertSequenceEqual(result2, url)
+ self.assertSequenceEqual(result2, url2)
  self.assertSequenceEqual(result2, result.geturl())
 
  # check the fixpoint property of re-parsing the result of geturl()
@@ -175,9 +177,39 @@ def test_qs(self):
 
  def test_roundtrips(self):
  str_cases = [
+ ('path/to/file',
+ ('', '', 'path/to/file', '', '', ''),
+ ('', '', 'path/to/file', '', '')),
+ ('/path/to/file',
+ ('', '', '/path/to/file', '', '', ''),
+ ('', '', '/path/to/file', '', '')),
+ ('//path/to/file',
+ ('', 'path', '/to/file', '', '', ''),
+ ('', 'path', '/to/file', '', '')),
+ ('////path/to/file',
+ ('', '', '//path/to/file', '', '', ''),
+ ('', '', '//path/to/file', '', '')),
+ ('scheme:path/to/file',
+ ('scheme', '', 'path/to/file', '', '', ''),
+ ('scheme', '', 'path/to/file', '', '')),
+ ('scheme:/path/to/file',
+ ('scheme', '', '/path/to/file', '', '', ''),
+ ('scheme', '', '/path/to/file', '', '')),
+ ('scheme://path/to/file',
+ ('scheme', 'path', '/to/file', '', '', ''),
+ ('scheme', 'path', '/to/file', '', '')),
+ ('scheme:////path/to/file',
+ ('scheme', '', '//path/to/file', '', '', ''),
+ ('scheme', '', '//path/to/file', '', '')),
  ('file:///tmp/junk.txt',
  ('file', '', '/tmp/junk.txt', '', '', ''),
  ('file', '', '/tmp/junk.txt', '', '')),
+ ('file:////tmp/junk.txt',
+ ('file', '', '//tmp/junk.txt', '', '', ''),
+ ('file', '', '//tmp/junk.txt', '', '')),
+ ('file://///tmp/junk.txt',
+ ('file', '', '///tmp/junk.txt', '', '', ''),
+ ('file', '', '///tmp/junk.txt', '', '')),
  ('imap://mail.python.org/mbox1',
  ('imap', 'mail.python.org', '/mbox1', '', '', ''),
  ('imap', 'mail.python.org', '/mbox1', '', '')),
@@ -213,6 +245,38 @@ def _encode(t):
  for url, parsed, split in str_cases + bytes_cases:
  self.checkRoundtrips(url, parsed, split)
 
+ def test_roundtrips_normalization(self):
+ str_cases = [
+ ('///path/to/file',
+ '/path/to/file',
+ ('', '', '/path/to/file', '', '', ''),
+ ('', '', '/path/to/file', '', '')),
+ ('scheme:///path/to/file',
+ 'scheme:/path/to/file',
+ ('scheme', '', '/path/to/file', '', '', ''),
+ ('scheme', '', '/path/to/file', '', '')),
+ ('file:/tmp/junk.txt',
+ 'file:///tmp/junk.txt',
+ ('file', '', '/tmp/junk.txt', '', '', ''),
+ ('file', '', '/tmp/junk.txt', '', '')),
+ ('http:/tmp/junk.txt',
+ 'http:///tmp/junk.txt',
+ ('http', '', '/tmp/junk.txt', '', '', ''),
+ ('http', '', '/tmp/junk.txt', '', '')),
+ ('https:/tmp/junk.txt',
+ 'https:///tmp/junk.txt',
+ ('https', '', '/tmp/junk.txt', '', '', ''),
+ ('https', '', '/tmp/junk.txt', '', '')),
+ ]
+ def _encode(t):
+ return (t[0].encode('ascii'),
+ t[1].encode('ascii'),
+ tuple(x.encode('ascii') for x in t[2]),
+ tuple(x.encode('ascii') for x in t[3]))
+ bytes_cases = [_encode(x) for x in str_cases]
+ for url, url2, parsed, split in str_cases + bytes_cases:
+ self.checkRoundtrips(url, parsed, split, url2)
+
  def test_http_roundtrips(self):
  # urllib.parse.urlsplit treats 'http:' as an optimized special case,
  # so we test both 'http:' and 'https:' in all the following.

Lib/urllib/parse.py

@@ -525,7 +525,7 @@ def urlunsplit(components):
  empty query; the RFC states that these are equivalent)."""
  scheme, netloc, url, query, fragment, _coerce_result = (
  _coerce_args(*components))
- if netloc or (scheme and scheme in uses_netloc and url[:2] != '//'):
+ if netloc or (scheme and scheme in uses_netloc) or url[:2] == '//':
  if url and url[:1] != '/': url = '/' + url
  url = '//' + (netloc or '') + url
  if scheme:

Misc/NEWS.d/next/Library/2019-08-27-01-16-50.gh-issue-67693.4NIAiy.rst

@@ -0,0 +1,2 @@
+Fix :func:`urllib.parse.urlunparse` and :func:`urllib.parse.urlunsplit` for URIs with path starting with multiple slashes and no authority.
+Based on patch by Ashwin Ramaswami.