Multiple apps break view -> controller bindings as of 1.12

[botandrose]

Hi folks, thanks for Ember!

I just upgraded my app to the latest stable release (1.12) and noticed a regression: If you have multiple Ember apps on a single page, some of the view -> controller bindings stop working on the first app. Below is a JSbin reproducing the bug, with steps to reproduce.

http://emberjs.jsbin.com/topehoyewu/1/

If you change the links in the HTML to link to ember v1.11.3, the bindings work, so the regression was introduced in 1.12, so my guess is that its related to some of the fastboot groundwork. I've tried it in 1.13.beta.1 and 2.0 canary, and the bug is there as well.

I'd love to help get this fixed, but I'll need some guidance on how to turn this into a failing test, since it involves multiple apps. Any advice?

[botandrose]

Okay, got a big ugly integration test that reproduces the failure, and git bisect reveals that 6a71ff2 caused this regression. For completeness, here is the failing test: https://gist.github.com/botandrose/afe8cae68ec031362640

I don't understand Ember's internals well enough to know what's the best thing to do here. But I could always open a PR that adds the test and reverts that commit. What do you think?

[rwjblue]

@botandrose - That was very helpful, thank you for taking the time to bisect.

[botandrose]

No problem. Let me know if there's anything else I can do to help.