Fix tests on Python 2, and fix broken timeout on Python 2

src/gevent/resolver/dnspython.py

 # Copyright (c) 2018  gevent contributors. See LICENSE for details.
 
 import _socket
-from socket import AI_NUMERICHOST
-from socket import gaierror
+from _socket import AI_NUMERICHOST
+from _socket import error
+from _socket import NI_NUMERICSERV
+
+import socket
 
 from . import AbstractResolver
 
 from dns import resolver
-from dns.resolver import _getaddrinfo
-
-from gevent import Timeout
-
-def _safe_getaddrinfo(*args, **kwargs):
-    try:
-        return _getaddrinfo(*args, **kwargs)
-    except gaierror as ex:
-        if isinstance(getattr(ex, '__context__', None),
-                      (Timeout, KeyboardInterrupt, SystemExit)):
-            raise ex.__context__
-        raise
+import dns
 
-resolver._getaddrinfo = _safe_getaddrinfo
 
 __all__ = [
     'Resolver',
 ]
 
+# This is a copy of resolver._getaddrinfo with the crucial change that it
+# doesn't have a bare except:, because that breaks Timeout and KeyboardInterrupt
+# See https://github.com/rthalley/dnspython/pull/300
+def _getaddrinfo(host=None, service=None, family=socket.AF_UNSPEC, socktype=0,
+                 proto=0, flags=0):
+    # pylint:disable=too-many-locals,broad-except,too-many-statements
+    # pylint:disable=too-many-branches
+    # pylint:disable=redefined-argument-from-local
+    if flags & (socket.AI_ADDRCONFIG | socket.AI_V4MAPPED) != 0:
+        raise NotImplementedError
+    if host is None and service is None:
+        raise socket.gaierror(socket.EAI_NONAME)
+    v6addrs = []
+    v4addrs = []
+    canonical_name = None
+    try:
+        # Is host None or a V6 address literal?
+        if host is None:
+            canonical_name = 'localhost'
+            if flags & socket.AI_PASSIVE != 0:
+                v6addrs.append('::')
+                v4addrs.append('0.0.0.0')
+            else:
+                v6addrs.append('::1')
+                v4addrs.append('127.0.0.1')
+        else:
+            parts = host.split('%')
+            if len(parts) == 2:
+                ahost = parts[0]
+            else:
+                ahost = host
+            addr = dns.ipv6.inet_aton(ahost)
+            v6addrs.append(host)
+            canonical_name = host
+    except Exception:
+        try:
+            # Is it a V4 address literal?
+            addr = dns.ipv4.inet_aton(host)
+            v4addrs.append(host)
+            canonical_name = host
+        except Exception:
+            if flags & socket.AI_NUMERICHOST == 0:
+                try:
+                    if family == socket.AF_INET6 or family == socket.AF_UNSPEC:
+                        v6 = resolver._resolver.query(host, dns.rdatatype.AAAA,
+                                                      raise_on_no_answer=False)
+                        # Note that setting host ensures we query the same name
+                        # for A as we did for AAAA.
+                        host = v6.qname
+                        canonical_name = v6.canonical_name.to_text(True)
+                        if v6.rrset is not None:
+                            for rdata in v6.rrset:
+                                v6addrs.append(rdata.address)
+                    if family == socket.AF_INET or family == socket.AF_UNSPEC:
+                        v4 = resolver._resolver.query(host, dns.rdatatype.A,
+                                                      raise_on_no_answer=False)
+                        host = v4.qname
+                        canonical_name = v4.canonical_name.to_text(True)
+                        if v4.rrset is not None:
+                            for rdata in v4.rrset:
+                                v4addrs.append(rdata.address)
+                except dns.resolver.NXDOMAIN:
+                    raise socket.gaierror(socket.EAI_NONAME)
+                except Exception:
+                    raise socket.gaierror(socket.EAI_SYSTEM)
+    port = None
+    try:
+        # Is it a port literal?
+        if service is None:
+            port = 0
+        else:
+            port = int(service)
+    except Exception:
+        if flags & socket.AI_NUMERICSERV == 0:
+            try:
+                port = socket.getservbyname(service)
+            except Exception:
+                pass
+    if port is None:
+        raise socket.gaierror(socket.EAI_NONAME)
+    tuples = []
+    if socktype == 0:
+        socktypes = [socket.SOCK_DGRAM, socket.SOCK_STREAM]
+    else:
+        socktypes = [socktype]
+    if flags & socket.AI_CANONNAME != 0:
+        cname = canonical_name
+    else:
+        cname = ''
+    if family == socket.AF_INET6 or family == socket.AF_UNSPEC:
+        for addr in v6addrs:
+            for socktype in socktypes:
+                for proto in resolver._protocols_for_socktype[socktype]:
+                    tuples.append((socket.AF_INET6, socktype, proto,
+                                   cname, (addr, port, 0, 0)))
+    if family == socket.AF_INET or family == socket.AF_UNSPEC:
+        for addr in v4addrs:
+            for socktype in socktypes:
+                for proto in resolver._protocols_for_socktype[socktype]:
+                    tuples.append((socket.AF_INET, socktype, proto,
+                                   cname, (addr, port)))
+    if len(tuples) == 0: # pylint:disable=len-as-condition
+        raise socket.gaierror(socket.EAI_NONAME)
+    return tuples
+
+
 class Resolver(AbstractResolver):
     """
     A resolver that uses dnspython.
@@ -37,10 +134,8 @@ class Resolver(AbstractResolver):
     This uses thread locks and sockets, so it only functions if the system
     has been monkey-patched. Otherwise it will raise a ``ValueError``.
 
-    This can cause timeouts to be lost: there is a bare `except:` clause
-    in the dnspython code that will catch all timeout exceptions gevent raises and
-    translate them into socket errors. On Python 3 we can detect this, but
-    on Python 2 we cannot.
+    Under Python 2, if the ``idna`` package is installed, this resolver
+    can resolve Unicode host names that the system resolver cannot.
 
     .. versionadded:: 1.3a2
     """
@@ -51,6 +146,8 @@ class Resolver(AbstractResolver):
             raise ValueError("Can only be used when monkey-patched")
         if resolver._resolver is None:
             resolver._resolver = resolver.get_default_resolver()
+        if resolver._getaddrinfo is not _getaddrinfo:
+            resolver._getaddrinfo = _getaddrinfo
 
     def close(self):
         pass
@@ -64,13 +161,21 @@ class Resolver(AbstractResolver):
             # 3) AI_NUMERICHOST flag is set
             return _socket.getaddrinfo(host, port, family, socktype, proto, flags)
 
-        return resolver._getaddrinfo(host, port, family, socktype, proto, flags)
+        return _getaddrinfo(host, port, family, socktype, proto, flags)
 
     def getnameinfo(self, sockaddr, flags):
-        if sockaddr and isinstance(sockaddr, (list, tuple)) and sockaddr[0] in ('::1', '127.0.0.1'):
+        if (sockaddr
+                and isinstance(sockaddr, (list, tuple))
+                and sockaddr[0] in ('::1', '127.0.0.1', 'localhost')):
             return _socket.getnameinfo(sockaddr, flags)
-
+        try:
             return resolver._getnameinfo(sockaddr, flags)
+        except error:
+            if not flags:
+                # dnspython doesn't like getting ports it can't resolve.
+                # We have one test, test__socket_dns.py:Test_getnameinfo_geventorg.test_port_zero
+                # that does this. We conservatively fix it here; this could be expanded later.
+                return resolver._getnameinfo(sockaddr, NI_NUMERICSERV)
 
     def gethostbyaddr(self, ip_address):
         if ip_address in (u'127.0.0.1', u'::1',

src/greentest/test__socket_dns.py

@@ -8,12 +8,13 @@ if ['gevent.resolver.dnspython.Resolver'] == gevent.get_hub().resolver_class:
     # dnspython requires monkey-patching
     monkey.patch_all()
 
-
+import os
 import re
 import greentest
 import unittest
 import socket
 from time import time
+import traceback
 import gevent.socket as gevent_socket
 from greentest.util import log
 from greentest import six
@@ -34,7 +35,7 @@ from greentest.sysinfo import PY2
 assert gevent_socket.gaierror is socket.gaierror
 assert gevent_socket.error is socket.error
 
-DEBUG = False
+DEBUG = os.getenv('GEVENT_DEBUG', '') == 'trace'
 
 
 def _run(function, *args):
@@ -43,6 +44,8 @@ def _run(function, *args):
         assert not isinstance(result, BaseException), repr(result)
         return result
     except Exception as ex:
+        if DEBUG:
+            traceback.print_exc()
         return ex
 
 
@@ -545,12 +548,15 @@ class Test_getaddrinfo(TestCase):
 class TestInternational(TestCase):
     pass
 
-add(TestInternational, u'президент.рф', 'russian')
+if not (PY2 and RESOLVER_DNSPYTHON):
+    # dns python can actually resolve these: it uses
+    # the 2008 version of idna encoding, whereas on Python 2,
+    # with the default resolver, it tries to encode to ascii and
+    # raises a UnicodeEncodeError. So we get different results.
+    add(TestInternational, u'президент.рф', 'russian')
 add(TestInternational, u'президент.рф'.encode('idna'), 'idna')
 
 
-@unittest.skipIf(RESOLVER_DNSPYTHON and PY2,
-                 "dnspython has a bare except and we can't workaround it on Python 2.")
 class TestInterrupted_gethostbyname(greentest.GenericWaitTestCase):
 
     # There are refs to a Waiter in the C code that don't go
@@ -562,7 +568,6 @@ class TestInterrupted_gethostbyname(greentest.GenericWaitTestCase):
     def wait(self, timeout):
         with gevent.Timeout(timeout, False):
             for index in xrange(1000000):
-                print("Resolving", index)
                 try:
                     gevent_socket.gethostbyname('www.x%s.com' % index)
                 except socket.error: