clientbot: add option to always autorejoin channels

Closes #647.

example-conf.yml

@@ -541,6 +541,10 @@ servers:
         #   - "MODE $nick +B"
         #   - "NOTICE somebody :hello, i've connected"
 
+        # Determines whether we should always attempt to rejoin channels we've been removed from.
+        # These attempts take place in the same interval as pingfreq. Defaults to false if not set.
+        #always_autorejoin: true
+
         # Determines whether oper statuses should be tracked on this Clientbot network. This
         # defaults to False for the best security, since oper status may allow more access to the
         # entire PyLink service than what's desired, even when PyLink is only connected as a bot.

protocols/clientbot.py

@@ -398,6 +398,13 @@ class ClientbotWrapperProtocol(ClientbotBaseProtocol, IRCCommonProtocol):
             for channel in self.pseudoclient.channels:
                 self._send_who(channel)
 
+            # Join persistent channels if always_autorejoin is enabled and there are any we're not in
+            if self.serverdata.get('always_autorejoin') and self.has_cap('can-manage-bot-channels'):
+                for channel in world.services['pylink'].get_persistent_channels(self):
+                    if channel not in self.pseudoclient.channels:
+                        log.info('(%s) Attempting to rejoin %s', self.name, channel)
+                        self.join(self.pseudoclient.uid, channel)
+
     def part(self, source, channel, reason=''):
         """STUB: Parts a user from a channel."""
         self._channels[channel].remove_user(source)