Make NoValidConnectionsError picklable correctly

Fixes #617.

3 files changed, 21 insertions, 1 deletions

diff --git a/paramiko/ssh_exception.py b/paramiko/ssh_exception.py
index 016a411e..b61000ae 100644
--- a/paramiko/ssh_exception.py
+++ b/paramiko/ssh_exception.py
@@ -173,3 +173,6 @@ class NoValidConnectionsError(socket.error):
             msg.format(addrs[0][1], body, tail)
         )
         self.errors = errors
+
+    def __reduce__(self):
+        return (NoValidConnectionsError, (self.errors, ))
diff --git a/test.py b/test.py
index 37fc5a6f..a1f13d85 100755
--- a/test.py
+++ b/test.py
@@ -43,8 +43,9 @@ from tests.test_kex import KexTest
 from tests.test_packetizer import PacketizerTest
 from tests.test_auth import AuthTest
 from tests.test_transport import TransportTest
+from tests.test_ssh_exception import NoValidConnectionsErrorTest
 from tests.test_client import SSHClientTest
-from test_client import SSHClientTest
+from test_client import SSHClientTest  # XXX why shadow the above import?
 from test_gssapi import GSSAPITest
 from test_ssh_gss import GSSAuthTest
 from test_kex_gss import GSSKexTest
@@ -156,6 +157,7 @@ def main():
     if options.use_transport:
         suite.addTest(unittest.makeSuite(AuthTest))
         suite.addTest(unittest.makeSuite(TransportTest))
+    suite.addTest(unittest.makeSuite(NoValidConnectionsErrorTest))
     suite.addTest(unittest.makeSuite(SSHClientTest))
     if options.use_sftp:
         suite.addTest(unittest.makeSuite(SFTPTest))
diff --git a/tests/test_ssh_exception.py b/tests/test_ssh_exception.py
new file mode 100644
index 00000000..2d1f899f
--- /dev/null
+++ b/tests/test_ssh_exception.py
@@ -0,0 +1,15 @@
+import pickle
+import unittest
+
+from paramiko.ssh_exception import NoValidConnectionsError
+
+
+class NoValidConnectionsErrorTest (unittest.TestCase):
+
+    def test_pickling(self):
+        # Regression test for https://github.com/paramiko/paramiko/issues/617
+        exc = NoValidConnectionsError({'ab': ''})
+        new_exc = pickle.loads(pickle.dumps(exc))
+        self.assertEqual(type(exc), type(new_exc))
+        self.assertEqual(str(exc), str(new_exc))
+        self.assertEqual(exc.args, new_exc.args)