Merge pull request #431 from mdickinson/fix-heartbeat-bind-socket

Fix Heartbeat._bind_socket to return on the first successful bind.

Author: blink1073

ipykernel/heartbeat.py

@@ -83,6 +83,8 @@ def _bind_socket(self):
                     self.pick_port()
                 else:
                     raise
+            else:
+                return
 
     def run(self):
         self.socket = self.context.socket(zmq.ROUTER)

ipykernel/tests/test_heartbeat.py

@@ -21,6 +21,13 @@ def test_port_bind_failure_raises():
         assert mock_try_bind.call_count == 1
 
 
+def test_port_bind_success():
+    heart = Heartbeat(None)
+    with patch.object(heart, '_try_bind_socket') as mock_try_bind:
+        heart._bind_socket()
+        assert mock_try_bind.call_count == 1
+
+
 def test_port_bind_failure_recovery():
     try:
         errno.WSAEADDRINUSE