From: Ben Darnell <ben@bendarnell.com>
Date: Sun, 12 Jun 2016 16:22:44 +0000 (-0400)
Subject: Standardize exceptions raised by Resolvers
X-Git-Tag: v4.4.0b1~9
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5ae369754fcc83862c5905bf6b66fec69b5d3be7;p=thirdparty%2Ftornado.git

Standardize exceptions raised by Resolvers

Fixes #1721
---

diff --git a/tornado/netutil.py b/tornado/netutil.py
index 348f3519c..5cbcdb925 100644
--- a/tornado/netutil.py
+++ b/tornado/netutil.py
@@ -332,6 +332,11 @@ class Resolver(Configurable):
         port)`` pair for IPv4; additional fields may be present for
         IPv6). If a ``callback`` is passed, it will be run with the
         result as an argument when it is complete.
+
+        :raises IOError: if the address cannot be resolved.
+
+        .. versionchanged:: 4.4
+           Standardized all implementations to raise `IOError`.
         """
         raise NotImplementedError()
 
diff --git a/tornado/platform/caresresolver.py b/tornado/platform/caresresolver.py
index d68b3fcc4..4205de30c 100644
--- a/tornado/platform/caresresolver.py
+++ b/tornado/platform/caresresolver.py
@@ -61,8 +61,8 @@ class CaresResolver(Resolver):
             assert not callback_args.kwargs
             result, error = callback_args.args
             if error:
-                raise Exception('C-Ares returned error %s: %s while resolving %s' %
-                                (error, pycares.errno.strerror(error), host))
+                raise IOError('C-Ares returned error %s: %s while resolving %s' %
+                              (error, pycares.errno.strerror(error), host))
             addresses = result.addresses
         addrinfo = []
         for address in addresses:
@@ -73,7 +73,7 @@ class CaresResolver(Resolver):
             else:
                 address_family = socket.AF_UNSPEC
             if family != socket.AF_UNSPEC and family != address_family:
-                raise Exception('Requested socket family %d but got %d' %
-                                (family, address_family))
+                raise IOError('Requested socket family %d but got %d' %
+                              (family, address_family))
             addrinfo.append((address_family, (address, port)))
         raise gen.Return(addrinfo)
diff --git a/tornado/platform/twisted.py b/tornado/platform/twisted.py
index 653a79ffc..92157c7c0 100644
--- a/tornado/platform/twisted.py
+++ b/tornado/platform/twisted.py
@@ -556,7 +556,10 @@ class TwistedResolver(Resolver):
             deferred = self.resolver.getHostByName(utf8(host))
             resolved = yield gen.Task(deferred.addBoth)
             if isinstance(resolved, failure.Failure):
-                resolved.raiseException()
+                try:
+                    resolved.raiseException()
+                except twisted.names.error.DomainError as e:
+                    raise IOError(e)
             elif twisted.internet.abstract.isIPAddress(resolved):
                 resolved_family = socket.AF_INET
             elif twisted.internet.abstract.isIPv6Address(resolved):
diff --git a/tornado/test/netutil_test.py b/tornado/test/netutil_test.py
index 2f4207a3e..a645bef21 100644
--- a/tornado/test/netutil_test.py
+++ b/tornado/test/netutil_test.py
@@ -64,7 +64,7 @@ class _ResolverErrorTestMixin(object):
 
     @gen_test
     def test_future_interface_bad_host(self):
-        with self.assertRaises(Exception):
+        with self.assertRaises(IOError):
             yield self.resolver.resolve('an invalid domain', 80,
                                         socket.AF_UNSPEC)