Open Radar

 
Sample code:
https://www.dropbox.com/s/k5m73zgnehqcfib/navbar-status-bar-hidden-glitch.m.txt?dl=0

Summary:
In a navigation controller where the top view controller has its status bar hidden but the previous one does not, if the user taps the back button, the navigation bar will be updated erroneously.

For instance, let's say you have a stack of view controller One, Two, Three where both One and Two have their `prefersStatusBarHidden` method return NO while Three has it returning YES. If the user taps the back button, the navigation controller will pop Three and display the contents of Two as expected, but the navbar will show One's title instead of Two's.

The behavior is different but still broken if the user swipes to pop Three but cancels in the middle. Tapping the back button will then take the user to the right contents + nav bar title (showing Two's contents and title), but tapping back again will cause a glitch where the nav bar remains showing Two's title forever.

Steps to Reproduce:
1. Push 3 controllers onto the stack of a nav controller: One, Two and Three, where One and Two have their `prefersStatusBarHidden` method return NO while Three has it returning YES.
2. Tap the back button on Three.


Expected Results:
It should show view controller Two's view in the contents alongside Two's title in the nav bar and a back button leading to One.

Actual Results:
It shows view controller Two's view but with One's title in the nav bar, with no back button.

Version:
iOS 8 (12A365)

Notes:
I confirmed that this does not happen on 7.1.

Configuration:
iPhone 6 Simulator