Fix joins to many channels (#1473)

* Fix joins to many channels

If you have enough channels that the 512 byte message limit on the JOIN
message is hit then limnoria was losing the channel that put it over the
limit and not including it in the next JOIN message. This resulted in
losing one channel for every JOIN message that pushed us over 512 bytes.

We fix this by generating the JOIN message immediately after resetting
the channels list to ensure we include the channel that pushed us over
the limit. Then the next time through our JOIN msg construction we'll
add subsequent channels without forgetting the one that pushed us over.

* Add test for channel join lists

This adds a test for the issue that is fixed in the previous commit. We
ensure that when JOINs are split over multiple messages we JOIN to all
channels that were part of the input list and don't forget any of them.

src/conf.py

@@ -339,10 +339,19 @@ class SpaceSeparatedSetOfChannels(registry.SpaceSeparatedListOf):
                 channels.append(channel)
             msg = ircmsgs.joins(channels_with_key + channels, keys)
             if len(str(msg)) > 512:
+                # Use previous short enough join message
                 msgs.append(old)
+                # Reset and construct a new join message using the current
+                # channel.
                 keys = []
                 channels_with_key = []
                 channels = []
+                if key:
+                    keys.append(key)
+                    channels_with_key.append(channel)
+                else:
+                    channels.append(channel)
+                msg = ircmsgs.joins(channels_with_key + channels, keys)
             old = msg
         if msg:
             msgs.append(msg)

test/test_conf.py

@@ -0,0 +1,59 @@
+##
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+#
+#   * Redistributions of source code must retain the above copyright notice,
+#     this list of conditions, and the following disclaimer.
+#   * Redistributions in binary form must reproduce the above copyright notice,
+#     this list of conditions, and the following disclaimer in the
+#     documentation and/or other materials provided with the distribution.
+#   * Neither the name of the author of this software nor the name of
+#     contributors to this software may be used to endorse or promote products
+#     derived from this software without specific prior written consent.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+###
+
+from supybot.test import *
+
+import supybot.conf as conf
+import supybot.registry as registry
+import supybot.ircutils as ircutils
+
+
+class SupyConfTestCase(SupyTestCase):
+    def testJoinToOneChannel(self):
+        orig = conf.supybot.networks.test.channels()
+        channels = ircutils.IrcSet()
+        channels.add("#bar")
+        conf.supybot.networks.test.channels.setValue(channels)
+        msgs = conf.supybot.networks.test.channels.joins()
+        self.assertEqual(msgs[0].args, ("#bar",))
+        conf.supybot.networks.test.channels.setValue(orig)
+
+    def testJoinToManyChannels(self):
+        orig = conf.supybot.networks.test.channels()
+        channels = ircutils.IrcSet()
+        input_list = []
+        for x in range(1, 30):
+            name = "#verylongchannelname" + str(x)
+            channels.add(name)
+            input_list.append(name)
+        conf.supybot.networks.test.channels.setValue(channels)
+        msgs = conf.supybot.networks.test.channels.joins()
+        # Double check we split the messages
+        self.assertEqual(len(msgs), 2)
+        # Ensure all channel names are present
+        chan_list = (msgs[0].args[0] + ',' + msgs[1].args[0]).split(',')
+        self.assertCountEqual(input_list, chan_list)
+        conf.supybot.networks.test.channels.setValue(orig)