SingletonExtensionPoint should return instantiated Component?

[Alec Thomas]

I think it would be more consistent if the default implementation argument of SingletonExtensionPoint were returned as an insantiated component.

ergo this patch:

trac/core.py

@@ -65 +65 @@
             if impl.__class__.__name__ == cfgvalue:
                 return impl
         if self.default is not None:
-            return self.default
+            return self.default(component.env)
         raise AttributeError('Cannot find an implementation of the "%s" '
                              'interface named "%s".  Please update your '
                              'trac.ini setting "%s.%s"'

Which would, of course, be used like this:

    workflow = SingletonExtensionPoint(ITicketWorkflow, 'ticket', 'workflow',
                                       DefaultTicketWorkflow)
...

    workflow = TicketSystem(self.env).workflow

# as opposed to this

    workflow = TicketSystem(self.env).workflow(self.env)

A minor nit.

[Matthew Good]

Actually I would consider that a defect since the return type is inconsistent.

Anyways, fixed in [2939].