bpo-39057: Fix urllib.request.proxy_bypass_environment(). (GH-17619)

Ignore leading dots and no longer ignore a trailing newline. (cherry picked from commit 6a265f0) Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>

Author: miss-islington

Lib/test/test_urllib.py

@@ -253,14 +253,36 @@ def test_proxy_bypass_environment_host_match(self):
  self.assertTrue(bypass('localhost'))
  self.assertTrue(bypass('LocalHost')) # MixedCase
  self.assertTrue(bypass('LOCALHOST')) # UPPERCASE
+ self.assertTrue(bypass('.localhost'))
  self.assertTrue(bypass('newdomain.com:1234'))
+ self.assertTrue(bypass('.newdomain.com:1234'))
  self.assertTrue(bypass('foo.d.o.t')) # issue 29142
+ self.assertTrue(bypass('d.o.t'))
  self.assertTrue(bypass('anotherdomain.com:8888'))
+ self.assertTrue(bypass('.anotherdomain.com:8888'))
  self.assertTrue(bypass('www.newdomain.com:1234'))
  self.assertFalse(bypass('prelocalhost'))
  self.assertFalse(bypass('newdomain.com')) # no port
  self.assertFalse(bypass('newdomain.com:1235')) # wrong port
 
+ def test_proxy_bypass_environment_always_match(self):
+ bypass = urllib.request.proxy_bypass_environment
+ self.env.set('NO_PROXY', '*')
+ self.assertTrue(bypass('newdomain.com'))
+ self.assertTrue(bypass('newdomain.com:1234'))
+ self.env.set('NO_PROXY', '*, anotherdomain.com')
+ self.assertTrue(bypass('anotherdomain.com'))
+ self.assertFalse(bypass('newdomain.com'))
+ self.assertFalse(bypass('newdomain.com:1234'))
+
+ def test_proxy_bypass_environment_newline(self):
+ bypass = urllib.request.proxy_bypass_environment
+ self.env.set('NO_PROXY',
+ 'localhost, anotherdomain.com, newdomain.com:1234')
+ self.assertFalse(bypass('localhost\n'))
+ self.assertFalse(bypass('anotherdomain.com:8888\n'))
+ self.assertFalse(bypass('newdomain.com:1234\n'))
+
 
 class ProxyTests_withOrderedEnv(unittest.TestCase):
 

Lib/urllib/parse.py

@@ -997,9 +997,9 @@ def splitport(host):
  """splitport('host:port') --> 'host', 'port'."""
  global _portprog
  if _portprog is None:
- _portprog = re.compile('(.*):([0-9]*)$', re.DOTALL)
+ _portprog = re.compile('(.*):([0-9]*)', re.DOTALL)
 
- match = _portprog.match(host)
+ match = _portprog.fullmatch(host)
  if match:
  host, port = match.groups()
  if port:

Lib/urllib/request.py

@@ -2499,24 +2499,26 @@ def proxy_bypass_environment(host, proxies=None):
  try:
  no_proxy = proxies['no']
  except KeyError:
- return 0
+ return False
  # '*' is special case for always bypass
  if no_proxy == '*':
- return 1
+ return True
+ host = host.lower()
  # strip port off host
  hostonly, port = splitport(host)
  # check if the host ends with any of the DNS suffixes
- no_proxy_list = [proxy.strip() for proxy in no_proxy.split(',')]
- for name in no_proxy_list:
+ for name in no_proxy.split(','):
+  name = name.strip()
  if name:
  name = name.lstrip('.') # ignore leading dots
- name = re.escape(name)
- pattern = r'(.+\.)?%s$' % name
- if (re.match(pattern, hostonly, re.I)
- or re.match(pattern, host, re.I)):
- return 1
+ name = name.lower()
+ if hostonly == name or host == name:
+ return True
+ name = '.' + name
+ if hostonly.endswith(name) or host.endswith(name):
+ return True
  # otherwise, don't bypass
- return 0
+ return False
 
 
 # This code tests an OSX specific data structure but is testable on all
@@ -2642,7 +2644,7 @@ def getproxies_registry():
  for p in proxyServer.split(';'):
  protocol, address = p.split('=', 1)
  # See if address has a type:// prefix
- if not re.match('^([^/:]+)://', address):
+ if not re.match('(?:[^/:]+)://', address):
  address = '%s://%s' % (protocol, address)
  proxies[protocol] = address
  else:

Misc/NEWS.d/next/Library/2019-12-15-21-47-54.bpo-39057.FOxn-w.rst

@@ -0,0 +1,2 @@
+:func:`urllib.request.proxy_bypass_environment` now ignores leading dots and
+no longer ignores a trailing newline.