registry: fix Regexp initialization when the default value is not None.

src/registry.py

@@ -751,14 +751,21 @@ class Regexp(Value):
     """Value must be a valid regular expression."""
     errormsg = _('Value must be a valid regular expression, not %r.')
 
+    def __init__(self, default, *args, **kwargs):
+        # We're not supposed to do convertions here, BUT this is needed
+        # when the value is set programmatically because the value
+        # plugins set (a string) is not the same as the one they get
+        # (a compiled pattern object)
+        default = self._convertFromString(default)
+        super().__init__(default, *args, **kwargs)
+
     def error(self, e):
         s = 'Value must be a regexp of the form m/.../ or /.../. %s' % e
         e = InvalidRegistryValue(s)
         e.value = self
         raise e
 
-    def set(self, s):
-        try:
+    def _convertFromString(self, s):
         if s:
             # We need to preserve the original string, as it's shown in
             # the user interface and the config file.
@@ -766,9 +773,13 @@ class Regexp(Value):
             # attribute, but doing so would result in inconsistent states
             # for childs of this variable, should they be reset, or the
             # value of there parent change.
-                v = (s, utils.str.perlReToPythonRe(s))
+            return (s, utils.str.perlReToPythonRe(s))
         else:
-                v = None
+            return None
+
+    def set(self, s):
+        try:
+            v = self._convertFromString(s)
         except ValueError as e:
             self.error(e)
         else:

test/test_registry.py

@@ -183,6 +183,16 @@ class ValuesTestCase(SupyTestCase):
         v.set('')
         self.assertEqual(v(), None)
 
+    def testRegexpDefaultString(self):
+        v = registry.Regexp('m/foo/', 'help')
+        self.assertEqual(v(), re.compile('foo'))
+
+        v = registry.Regexp('', 'help')
+        self.assertEqual(v(), None)
+
+        v = registry.Regexp(None, 'help')
+        self.assertEqual(v(), None)
+
     def testBackslashesKeys(self):
         conf.supybot.reply.whenAddressedBy.strings.get(':foo').set('=/*')
         filename = conf.supybot.directories.conf.dirize('backslashes1.conf')