Connection: disconnect if we get no PONG for our PING

Previously we'd just send out a PING into the æther every n seconds, and
pay no attention to whether we ever got an answer. So it was perfectly
possible for the connection to just sit there until the TCP timeout
kicks in, which I think is a matter of hours by default.

With this patch, if we haven't heard a PONG 3 keepalive-intervals after
sending a PING, Idle throws its toys out of the pram.

This has been tested as follows:

* Put my laptop on a wired and wireless network simultaneously.
* Connect to an IRC server. (The wired network is used.)
* Pull the network cable out. Idle is too stupid to realise the link it
  was using is gone, and because we're still ostensibly online, nothing
  tells it to disconnect.
* Wait keepalive-interval * 4, and watch the connection get
  disconnected.

It works both with a direct connection to Freenode, and with a
connection over an SSH tunnel to irssi-proxy.

1 files changed, 16 insertions, 3 deletions

diff --git a/tests/twisted/connect/ping.py b/tests/twisted/connect/ping.py
index 7d77341..9c1f6ca 100644
--- a/tests/twisted/connect/ping.py
+++ b/tests/twisted/connect/ping.py
@@ -1,9 +1,10 @@
 """
-Test Idle sending PINGs.
+Test Idle sending PINGs and timing out if it doesn't get a reply.
 """
 
 from idletest import exec_test
-from servicetest import assertLength
+from servicetest import assertLength, EventPattern
+import constants as cs
 
 def test(q, bus, conn, stream):
     conn.Connect()
@@ -15,8 +16,20 @@ def test(q, bus, conn, stream):
     stream.sendMessage('PONG', 'idle.test.server', ':%s' % timestamp,
         prefix='idle.test.server')
 
+    q.expect('stream-PING')
+    # If we don't answer Idle's ping, after some period of time Idle should
+    # give up and close the connection.
+    q.expect_many(
+        EventPattern('irc-disconnected'),
+        EventPattern('dbus-signal', signal='StatusChanged',
+            args=[cs.CONN_STATUS_DISCONNECTED, cs.CSR_NETWORK_ERROR]),
+        )
+
 if __name__ == '__main__':
-    exec_test(test, params={
+    # We expect Idle to blow up the connection after three intervals without a
+    # reply. So the default 5-second test timeout *should* just be enough, but
+    # let's not risk it.
+    exec_test(test, timeout=10, params={
         'keepalive-interval': 1,
     })