Component's {{link-to}} tabindex doesn't toggle based on component property when tabindex starts at -1

[melodyma]

When tabindex starts at -1 for a {{link-to}} in a component and bound to a component's property, the {{link-to}}'s tabindex doesn't toggle based on the component's property even though the property is toggling. It's not updating the DOM.

See jsbin here for example: See jbin: http://emberjs.jsbin.com/zixohejive/edit?html,js,output

Proper tabindex toggling based on state is required for writing accessible components.

[raytiley]

I imagine this has the same root cause as #11699
Seems link-to has issues with updating attributes after initial render

[rwjblue]

Closing this in favor of #11699 (trying to consolidate).

[rwjblue]

Fixed by #11960.