Debug display traces decorator instead of view on error

[briand]

I'm not sure what other error conditions may cause this to happen, but in my case it was a decorated view function where I forgot to return an HttpResponse object.

The view function:

@login_required
def index(request):
    pass

Throws the debugger page message:

The view django.contrib.auth.decorators._CheckLogin.__call__ didn't return an HttpResponse object.

And only shows the traceback on the decorator, no traceback context for the actual failing view is displayed. Any reasonably astute developer would realize where the error is really coming from, but given an otherwise complete view it took me a few minutes to realize my last statement was a render_to_response call without a preceeding return statement.

[Malcolm Tredinnick]

This is essentially a variation on #5701 (and some other related tickets) regarding setting up attributes on decorators correctly.