[3.8] bpo-27657: Fix urlparse() with numeric paths (GH-661)backport-5a88d50-3.8

* bpo-27657: Fix urlparse() with numeric paths

Revert parsing decision from bpo-754016 in favor of the documented
consensus in bpo-16932 of how to treat strings without a // to
designate the netloc.

* bpo-22891: Remove urlsplit() optimization for 'http' prefixed inputs.
(cherry picked from commit 5a88d50ff013a64fbdb25b877c87644a9034c969)

Co-authored-by: Tim Graham <timograham@gmail.com>

3 files changed, 9 insertions, 25 deletions

diff --git a/Lib/test/test_urlparse.py b/Lib/test/test_urlparse.py
index 4ae6ed3385..762500789f 100644
--- a/Lib/test/test_urlparse.py
+++ b/Lib/test/test_urlparse.py
@@ -709,15 +709,17 @@ class UrlParseTestCase(unittest.TestCase):
 
     def test_portseparator(self):
         # Issue 754016 makes changes for port separator ':' from scheme separator
-        self.assertEqual(urllib.parse.urlparse("path:80"),
-                ('','','path:80','','',''))
+        self.assertEqual(urllib.parse.urlparse("http:80"), ('http','','80','','',''))
+        self.assertEqual(urllib.parse.urlparse("https:80"), ('https','','80','','',''))
+        self.assertEqual(urllib.parse.urlparse("path:80"), ('path','','80','','',''))
         self.assertEqual(urllib.parse.urlparse("http:"),('http','','','','',''))
         self.assertEqual(urllib.parse.urlparse("https:"),('https','','','','',''))
         self.assertEqual(urllib.parse.urlparse("http://www.python.org:80"),
                 ('http','www.python.org:80','','','',''))
         # As usual, need to check bytes input as well
-        self.assertEqual(urllib.parse.urlparse(b"path:80"),
-                (b'',b'',b'path:80',b'',b'',b''))
+        self.assertEqual(urllib.parse.urlparse(b"http:80"), (b'http',b'',b'80',b'',b'',b''))
+        self.assertEqual(urllib.parse.urlparse(b"https:80"), (b'https',b'',b'80',b'',b'',b''))
+        self.assertEqual(urllib.parse.urlparse(b"path:80"), (b'path',b'',b'80',b'',b'',b''))
         self.assertEqual(urllib.parse.urlparse(b"http:"),(b'http',b'',b'',b'',b'',b''))
         self.assertEqual(urllib.parse.urlparse(b"https:"),(b'https',b'',b'',b'',b'',b''))
         self.assertEqual(urllib.parse.urlparse(b"http://www.python.org:80"),
diff --git a/Lib/urllib/parse.py b/Lib/urllib/parse.py
index b6608783a8..d497925b94 100644
--- a/Lib/urllib/parse.py
+++ b/Lib/urllib/parse.py
@@ -431,31 +431,11 @@ def urlsplit(url, scheme='', allow_fragments=True):
     netloc = query = fragment = ''
     i = url.find(':')
     if i > 0:
-        if url[:i] == 'http': # optimize the common case
-            url = url[i+1:]
-            if url[:2] == '//':
-                netloc, url = _splitnetloc(url, 2)
-                if (('[' in netloc and ']' not in netloc) or
-                        (']' in netloc and '[' not in netloc)):
-                    raise ValueError("Invalid IPv6 URL")
-            if allow_fragments and '#' in url:
-                url, fragment = url.split('#', 1)
-            if '?' in url:
-                url, query = url.split('?', 1)
-            _checknetloc(netloc)
-            v = SplitResult('http', netloc, url, query, fragment)
-            _parse_cache[key] = v
-            return _coerce_result(v)
         for c in url[:i]:
             if c not in scheme_chars:
                 break
         else:
-            # make sure "url" is not actually a port number (in which case
-            # "scheme" is really part of the path)
-            rest = url[i+1:]
-            if not rest or any(c not in '0123456789' for c in rest):
-                # not a port number
-                scheme, url = url[:i].lower(), rest
+            scheme, url = url[:i].lower(), url[i+1:]
 
     if url[:2] == '//':
         netloc, url = _splitnetloc(url, 2)
diff --git a/Misc/NEWS.d/next/Library/2017-12-26-14-32-23.bpo-27657.6BhyVK.rst b/Misc/NEWS.d/next/Library/2017-12-26-14-32-23.bpo-27657.6BhyVK.rst
new file mode 100644
index 0000000000..77746c0ce6
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2017-12-26-14-32-23.bpo-27657.6BhyVK.rst
@@ -0,0 +1,2 @@
+Fix urllib.parse.urlparse() with numeric paths. A string like "path:80" is
+no longer parsed as a path but as a scheme ("path") and a path ("80").