Open Radar

 
Summary:
Not sure if this is an intended change, but...

When you  turn rotation lock on, this doesn't always force apps to go to portrait anymore. It just locks the rotation. This behavior is different from iOS8. Even if it's intended, it feels a bit off.

Steps to Reproduce:
1. make sure rotation lock is off and phone is in portrait
2. Open an app that supports full rotation (e.g, Mail)
3. rotate to landscape, the app UI adapts
4. go to the homescreen by pressing home button (the phone is now visually back in portrait)
5. rotate physically to portrait
6. open control center and engage rotation lock
7. go back to the previous app (in this case: Mail)

Expected Results:
The app is presented in portrait since we're locked to portrait.

Actual Results:
The app remains locked in it's last orientation (in this case landscape). Rotating has no effect. 

Notes:
Turning rotation lock off while in a "locked" app and then rotating the phone does change the app's orientation.