Generate dest for Options always

flake8/options/manager.py

@@ -72,7 +72,7 @@ class Option(object):
             'action': action,
             'default': default,
             'type': type,
-            'dest': dest,
+            'dest': self._make_dest(dest),
             'callback': callback,
             'callback_args': callback_args,
             'callback_kwargs': callback_kwargs,
@@ -93,7 +93,7 @@ class Option(object):
             if not long_option_name:
                 raise ValueError('When specifying parse_from_config=True, '
                                  'a long_option_name must also be specified.')
-            self.config_name = long_option_name.strip('-').replace('-', '_')
+            self.config_name = self.dest
 
     def __repr__(self):
         return (
@@ -103,6 +103,11 @@ class Option(object):
             'callback_kwargs={callback_kwargs}, metavar={metavar})'
             ).format(*self.option_args, **self.option_kwargs)
 
+    def _make_dest(self, dest):
+        if self.long_option_name:
+            return self.long_option_name[2:].replace('-', '_')
+        return self.short_option_name[1]
+
     def to_optparse(self):
         """Convert a Flake8 Option to an optparse Option."""
         if not hasattr(self, '_opt'):

tests/unit/test_option.py

@@ -32,7 +32,7 @@ def test_to_optparse_creates_an_option_as_we_expect(Option):
         'action': 'count',
         'default': None,
         'type': None,
-        'dest': None,
+        'dest': 'test',
         'callback': None,
         'callback_args': None,
         'callback_kwargs': None,