id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
16386	Handle subclasses in signal dispatcher	Patryk Zawadzki	nobody	"Currently the signal dispatcher stores just the identity of the passed object instead. Because of that the `_live_receivers` method can only perform equality tests. The result is that the moment you use Python inheritance for models, the signals stop working.

You can work around that by setting sender to `None` but it adds a bit of an overhead due to the fact that your handler is called for each and every object and there are places where you can't change how signals are connected (like the generic relations).

Therefore I propose modifying the `_make_id` function a bit so when passed a type (class) or a list/tuple of types it returns it verbatim without identity casting. Then `_live_receivers` could test for `issubclass` dealing with classes.

While this would technically result in a different behavior from what Django 1.3 does, I doubt it would be a problem. I don't think there are many cases when you want a signal from a base class but not from subclasses and the few remaining uses can manually test for that in the handler."	New feature	closed	Core (Other)	1.3	Normal	wontfix			Design decision needed	0	0	0	0	0	0