gh-76646: Fix proxy_bypass_registry trailing semicolon on Windows

Lib/test/test_urllib.py

@@ -1,7 +1,8 @@
 """Regression tests for what was in Python 2's "urllib" module"""
 
 import urllib.parse
-import urllib.request
+import urllib.request 
+import _proxy_bypass_winreg_override as proxy_bypass_winreg
 import urllib.error
 import http.client
 import email.message
@@ -1686,6 +1687,14 @@ def test_with_method_arg(self):
         request.method = 'HEAD'
         self.assertEqual(request.get_method(), 'HEAD')
 
+class ProxyBypassRegistryTests(unittest.TestCase):
+    def test_proxy_bypass_registry_trailing_semicolon(self):
+        fake_proxy_override = "localhost;*.example.com;"
+
+        # Directly test the internal function
+        self.assertFalse(proxy_bypass_winreg("notmatching.com", fake_proxy_override))
+        self.assertTrue(proxy_bypass_winreg("localhost", fake_proxy_override))
+        self.assertTrue(proxy_bypass_winreg("sub.example.com", fake_proxy_override))
 
 if __name__ == '__main__':
     unittest.main()

Lib/urllib/request.py

@@ -1996,7 +1996,7 @@ def ip2num(ipAddr):
 
 
 # Same as _proxy_bypass_macosx_sysconf, testable on all platforms
-def _proxy_bypass_winreg_override(host, override):
+def _proxy_bypass_winreg_override(host, proxyOverride):
     """Return True if the host should bypass the proxy server.
 
     The proxy override list is obtained from the Windows
@@ -2008,15 +2008,18 @@ def _proxy_bypass_winreg_override(host, override):
     from fnmatch import fnmatch
 
     host, _ = _splitport(host)
-    proxy_override = override.split(';')
-    for test in proxy_override:
-        test = test.strip()
+
+    # Split and remove empty or whitespace-only entries
+    proxyOverride = [x.strip() for x in proxyOverride.split(';') if x.strip()]
+
+    for test in proxyOverride:
         # "<local>" should bypass the proxy server for all intranet addresses
         if test == '<local>':
             if '.' not in host:
                 return True
         elif fnmatch(host, test):
             return True
+
     return False
 
 

Misc/NEWS.d/next/32465.proxy_bypass_trailing_semicolon.rst

@@ -0,0 +1,2 @@
+bpo-32465: _proxy_bypass_winreg_override strips empty entries from ProxyOverride on Windows.
+