The command finder function (I forget the name) would find serendipitously named methods in PrivmsgRegexp, and that's bad. Fixed and added a test for the known case of it.

src/callbacks.py

@@ -249,9 +249,10 @@ def findCallbackForCommand(irc, commandName):
     """Given a command name and an Irc object, returns the callback that
     command is in.  Returns None if there is no callback with that command."""
     for callback in irc.callbacks:
-        if hasattr(callback, 'isCommand'):
+        if not isinstance(callback, PrivmsgRegexp):
-            if callback.isCommand(commandName):
+            if hasattr(callback, 'isCommand'):
-                return callback
+                if callback.isCommand(commandName):
+                    return callback
     return None
 
 class IrcObjectProxy:

test/test_Ctcp.py

@@ -0,0 +1,41 @@
+#!/usr/bin/env python
+
+###
+# Copyright (c) 2002, Jeremiah Fincher
+# All rights reserved.
+#
+# 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 test import *
+
+class CtcpTestCase(PluginTestCase):
+    plugins = ('Ctcp',)
+    def testVersion(self):
+        self.assertNoResponse('version', 1)
+
+
+# vim:set shiftwidth=4 tabstop=8 expandtab textwidth=78:
+