matchHost: extend negation via "!" to regular hostmasks as well as exttargets

classes.py

@@ -1162,14 +1162,24 @@ class Irc(utils.DeprecatedAttributesObject):
         # Try to convert target into a UID. If this fails, it's probably a hostname.
         target = self.nickToUid(target) or target
 
+        # Allow queries like !$exttarget to invert the given match.
+        invert = glob.startswith('!')
+        if invert:
+            glob = glob.lstrip('!')
+
+        def match_host_core():
+            """
+            Core processor for matchHost(), minus the inversion check.
+            """
+            # Work with variables in the matchHost() scope, from
+            # http://stackoverflow.com/a/8178808
+            nonlocal glob
+
             # Prepare a list of hosts to check against.
             if target in self.users:
-            if glob.startswith(('$', '!$')):
-                # !$exttarget inverts the given match.
-                invert = glob.startswith('!$')
-
+                if glob.startswith('$'):
                     # Exttargets start with $. Skip regular ban matching and find the matching ban handler.
-                glob = glob.lstrip('$!')
+                    glob = glob.lstrip('$')
                     exttargetname = glob.split(':', 1)[0]
                     handler = world.exttarget_handlers.get(exttargetname)
 
@@ -1178,8 +1188,6 @@ class Irc(utils.DeprecatedAttributesObject):
                         result = handler(self, glob, target)
                         log.debug('(%s) Got %s from exttarget %s in matchHost() glob $%s for target %s',
                                   self.name, result, exttargetname, glob, target)
-                    if invert:  # Anti-exttarget was specified.
-                        result = not result
                         return result
                     else:
                         log.debug('(%s) Unknown exttarget %s in matchHost() glob $%s', self.name,
@@ -1222,6 +1230,11 @@ class Irc(utils.DeprecatedAttributesObject):
 
             return False
 
+        result = match_host_core()
+        if invert:
+            result = not result
+        return result
+
 class IrcUser():
     """PyLink IRC user class."""
     def __init__(self, nick, ts, uid, server, ident='null', host='null',