Add echo messages, either with the echo-message capability or simulated.

Plugin can opt in to getting echo messages by setting the class attribute
'echo_message = True' if they want to get echos.
This defaults to False in order not to break existing plugins, and because
they usually don't need it (there's outFilter for most cases).

src/irclib.py

@@ -117,6 +117,7 @@ class IrcCallback(IrcCommandDispatcher, log.Firewalled):
     """
     callAfter = ()
     callBefore = ()
+    echo_message = False
     __firewalled__ = {'die': None,
                       'reset': None,
                       '__call__': None,
@@ -181,6 +182,20 @@ class IrcCallback(IrcCommandDispatcher, log.Firewalled):
 
     def __call__(self, irc, msg):
         """Used for handling each message."""
+        if not self.echo_message \
+                and msg.command in ('PRIVMSG', 'NOTICE', 'TAGMSG') \
+                and ('label' in msg.server_tags
+                     or not msg.tagged('receivedAt')):
+            # This is an echo of a message we sent; and the plugin didn't
+            # opt-in to receiving echos; ignoring it.
+            # `'label' in msg.server_tags` detects echos when labeled-response
+            # is enabled; and `not msg.tag('receivedAt')` detects simulated
+            # echos. As we don't enable real echo-message unless
+            # labeled-response is enabled; this is an exhaustive check of echos
+            # in all cases.
+            # See "When a client sends a private message to its own nick" at
+            # <https://ircv3.net/specs/extensions/labeled-response>
+            return
         method = self.dispatchCommand(msg.command, msg.args)
         if method is not None:
             method(irc, msg)
@@ -1057,6 +1072,13 @@ class Irc(IrcCommandDispatcher, log.Firewalled):
 
             self._truncateMsg(msg)
 
+            if msg.command.upper() in ('PRIVMSG', 'NOTICE', 'TAGMSG') \
+                    and 'echo-message' not in self.state.capabilities_ack:
+                # echo-message is not implemented by server; let's emulate it
+                # here, just before sending it to the driver.
+                assert not msg.tagged('receivedAt')
+                self.feedMsg(msg, tag=False)
+            else:
                 # I don't think we should do this.  Why should it matter?  If it's
                 # something important, then the server will send it back to us,
                 # and if it's just a privmsg/notice/etc., we don't care.
@@ -1098,8 +1120,12 @@ class Irc(IrcCommandDispatcher, log.Firewalled):
         return channel.lstrip(statusmsg_chars)
 
     _numericErrorCommandRe = re.compile(r'^[45][0-9][0-9]$')
-    def feedMsg(self, msg):
+    def feedMsg(self, msg, tag=True):
-        """Called by the IrcDriver; feeds a message received."""
+        """Called by the IrcDriver; feeds a message received.
+
+        `tag=False` is used when simulating echo messages, to skip adding
+        received* tags."""
+        if tag:
             self._tagMsg(msg)
         channel = msg.channel
 
@@ -1250,11 +1276,12 @@ class Irc(IrcCommandDispatcher, log.Firewalled):
             self.REQUEST_CAPABILITIES.add('sasl')
 
 
+    # Note: echo-message is only requested if labeled-response is available.
     REQUEST_CAPABILITIES = set(['account-notify', 'extended-join',
         'multi-prefix', 'metadata-notify', 'account-tag',
         'userhost-in-names', 'invite-notify', 'server-time',
         'chghost', 'batch', 'away-notify', 'message-tags',
-        'msgid', 'setname', 'labeled-response'])
+        'msgid', 'setname', 'labeled-response', 'echo-message'])
 
     def _queueConnectMessages(self):
         if self.zombie:
@@ -1654,7 +1681,24 @@ class Irc(IrcCommandDispatcher, log.Firewalled):
     def _requestCaps(self, caps):
         self.state.capabilities_req |= caps
 
-        caps = ' '.join(sorted(caps))
+        caps = list(sorted(caps))
+        cap_lines = []
+        if 'echo-message' in caps \
+                and 'labeled-response' not in self.state.capabilities_ack:
+            # Make sure echo-message is never requested unless we either have
+            # labeled-response already, or we request it *on the same line*
+            # so they are both accepted or both rejected). The reason for this
+            # is that this is required to properly deal with PRIVMSGs sent to
+            # oneself.
+            # See "When a client sends a private message to its own nick" at
+            # <https://ircv3.net/specs/extensions/labeled-response>
+            caps.remove('echo-message')
+            if 'labeled-response' in caps:
+                caps.remove('labeled-response')
+                # This makes sure they are always on the same line (which
+                # happens to be the first):
+                caps = ['echo-message', 'labeled-response'] + caps
+        caps = ' '.join(caps)
         # textwrap works here because in ASCII, all chars are 1 bytes:
         cap_lines = textwrap.wrap(
             caps, MAX_LINE_SIZE-len('CAP REQ :'),

test/test_irclib.py

@@ -498,6 +498,68 @@ class IrcCapsTestCase(SupyTestCase):
         self.assertEqual(m.args[0], 'REQ', m)
         self.assertEqual(m.args[1], 'b'*400)
 
+    def testNoEchomessageWithoutLabeledresponse(self):
+        self.irc = irclib.Irc('test')
+
+        m = self.irc.takeMsg()
+        self.assertTrue(m.command == 'CAP', 'Expected CAP, got %r.' % m)
+        self.assertTrue(m.args == ('LS', '302'), 'Expected CAP LS 302, got %r.' % m)
+
+        m = self.irc.takeMsg()
+        self.assertTrue(m.command == 'NICK', 'Expected NICK, got %r.' % m)
+
+        m = self.irc.takeMsg()
+        self.assertTrue(m.command == 'USER', 'Expected USER, got %r.' % m)
+
+        self.irc.feedMsg(ircmsgs.IrcMsg(command='CAP',
+            args=('*', 'LS', 'account-notify echo-message')))
+
+        m = self.irc.takeMsg()
+        self.assertTrue(m.command == 'CAP', 'Expected CAP, got %r.' % m)
+        self.assertEqual(m.args[0], 'REQ', m)
+        self.assertEqual(m.args[1], 'account-notify')
+
+        m = self.irc.takeMsg()
+        self.assertIsNone(m)
+
+    def testEchomessageLabeledresponseGrouped(self):
+        self.irc = irclib.Irc('test')
+
+        m = self.irc.takeMsg()
+        self.assertTrue(m.command == 'CAP', 'Expected CAP, got %r.' % m)
+        self.assertTrue(m.args == ('LS', '302'), 'Expected CAP LS 302, got %r.' % m)
+
+        m = self.irc.takeMsg()
+        self.assertTrue(m.command == 'NICK', 'Expected NICK, got %r.' % m)
+
+        m = self.irc.takeMsg()
+        self.assertTrue(m.command == 'USER', 'Expected USER, got %r.' % m)
+
+        self.irc.REQUEST_CAPABILITIES = set([
+            'account-notify', 'a'*490, 'echo-message', 'labeled-response'])
+        self.irc.feedMsg(ircmsgs.IrcMsg(command='CAP', args=(
+            '*', 'LS',
+            'account-notify ' + 'a'*490 + ' echo-message labeled-response')))
+
+        m = self.irc.takeMsg()
+        self.assertTrue(m.command == 'CAP', 'Expected CAP, got %r.' % m)
+        self.assertEqual(m.args[0], 'REQ', m)
+        self.assertEqual(m.args[1], 'echo-message labeled-response')
+
+        m = self.irc.takeMsg()
+        self.assertTrue(m.command == 'CAP', 'Expected CAP, got %r.' % m)
+        self.assertEqual(m.args[0], 'REQ', m)
+        self.assertEqual(m.args[1], 'a'*490)
+
+        m = self.irc.takeMsg()
+        self.assertTrue(m.command == 'CAP', 'Expected CAP, got %r.' % m)
+        self.assertEqual(m.args[0], 'REQ', m)
+        self.assertEqual(m.args[1], 'account-notify')
+
+        m = self.irc.takeMsg()
+        self.assertIsNone(m)
+
+
 class StsTestCase(SupyTestCase):
     def setUp(self):
         self.irc = irclib.Irc('test')