Fix FutureWarning related to nested sets.

See https://bugs.python.org/issue30349

plugins/ChannelStats/plugin.py

@@ -292,7 +292,7 @@ class ChannelStats(callbacks.Plugin):
                              name, channel))
     stats = wrap(stats, ['channeldb', additional('something')])
 
-    _calc_match_forbidden_chars = re.compile('[_[\]]')
+    _calc_match_forbidden_chars = re.compile('[_\[\]]')
     _env = {'__builtins__': types.ModuleType('__builtins__')}
     _env.update(math.__dict__)
     def _factorial(x):

plugins/Math/plugin.py

@@ -157,7 +157,7 @@ class Math(callbacks.Plugin):
         else:
             return '%s%s' % (realS, imagS)
 
-    _calc_match_forbidden_chars = re.compile('[_[\]]')
+    _calc_match_forbidden_chars = re.compile('[_\[\]]')
     _calc_remover = utils.str.MultipleRemover('_[] \t')
     ###
     # So this is how the 'calc' command works:

plugins/Nickometer/plugin.py

@@ -151,7 +151,7 @@ class Nickometer(callbacks.Plugin):
             nickInitial = nick
             nick=re.sub('^([^()]*)(\()(.*)(\))([^()]*)$', '\1\3\5', nick, 1)
             nick=re.sub('^([^{}]*)(\{)(.*)(\})([^{}]*)$', '\1\3\5', nick, 1)
-            nick=re.sub('^([^[\]]*)(\[)(.*)(\])([^[\]]*)$', '\1\3\5', nick, 1)
+            nick=re.sub('^([^\[\]]*)(\[)(.*)(\])([^\[\]]*)$', '\1\3\5', nick, 1)
             if nick == nickInitial:
                 break
             self.log.debug('Removed some matching brackets %r => %r',

src/ircutils.py

@@ -181,7 +181,7 @@ def _hostmaskPatternEqual(pattern, hostmask):
             elif c == '?':
                 fd.write('.')
             elif c in '[{':
-                fd.write('[[{]')
+                fd.write(r'[\[{]')
             elif c in '}]':
                 fd.write(r'[}\]]')
             elif c in '|\\':