callbacks: Ignore chathistory batches in PluginRegexp

This is consistent with what we already do with commands; and generally
makes sense, as we don't want to re-send titles and others when cycling
on UnrealIRCd (which includes a chathistory batch when joining when
chmode +H is set, despite umode +B)

plugins/Owner/plugin.py

@@ -309,8 +309,9 @@ class Owner(callbacks.Plugin):
                 # Either sent automatically by the server upon join,
                 # or triggered by a plugin (why?!)
                 # Either way, replying to commands from the history would
-                # look weird, because it may have been sent a while ago,
+                # look weird, because they may have been sent a while ago,
-                # and we may have already answered to it.
+                # and we may have already answered to them.
+                # (this is the same behavior as in PluginRegexp.doPrivmsg)
                 return
 
         self._doPrivmsgs(irc, msg)

src/callbacks.py

@@ -1804,6 +1804,19 @@ class PluginRegexp(Plugin):
     def doPrivmsg(self, irc, msg):
         if msg.isError:
             return
+
+        if 'batch' in msg.server_tags:
+            parent_batches = irc.state.getParentBatches(msg)
+            parent_batch_types = [batch.type for batch in parent_batches]
+            if 'chathistory' in parent_batch_types:
+                # Either sent automatically by the server upon join,
+                # or triggered by a plugin (why?!)
+                # Either way, replying to messages from the history would
+                # look weird, because they may have been sent a while ago,
+                # and we may have already answered them.
+                # (this is the same behavior as in Owner.doPrivmsg)
+                return
+
         proxy = self.Proxy(irc, msg)
         if not msg.addressed:
             for (r, name) in self.unaddressedRes:

test/test_callbacks.py

@@ -1002,6 +1002,23 @@ class PluginRegexpTestCase(ChannelPluginTestCase):
             args=(self.channel, 'foo <bar> baz')))
         self.assertResponse(' ', 'hello')
 
+    def testIgnoreChathistory(self):
+        self.irc.feedMsg(ircmsgs.IrcMsg(
+            command='BATCH',
+            args=('+123', 'chathistory', self.channel)))
+
+        self.irc.feedMsg(ircmsgs.IrcMsg(
+            server_tags={'batch': '123'},
+            prefix=self.prefix,
+            command='PRIVMSG',
+            args=(self.channel, 'foo <bar> baz')))
+
+        self.irc.feedMsg(ircmsgs.IrcMsg(
+            command='BATCH',
+            args=('-123',)))
+
+        self.assertNoResponse(' ')
+
 class RichReplyMethodsTestCase(PluginTestCase):
     plugins = ('Config',)
     class NoCapability(callbacks.Plugin):