Open Radar

 
Area:
Core Bluetooth

Summary:
The sample App is the central and starts scanning when UIApplicationDidBecomeActive is fired and stops scanning when UIApplicationWillResignActive is fired. When pulling up the control center the app stops/starts scanning reliably. But when the app is suspended when pressing the home button and the user waits a little bit and opens the app again, scanning does NOT start.

Steps to Reproduce:
1. Add a service UUID to the sample project of a peripheral that is in the vicinity.
2. Open the App. The text view should be filled with logs of the peripherals properties and a log count.
3. Close the App by pressing the home button.
4. Wait for a short amount of time (~10s).
5. Open the App again.
6. The app now may NOT get new didDiscover peripheral calls.

Expected Results:
The app should get new didDiscover peripheral calls after scanForPeripherals was called when UIApplicationDidBecomeActive was fired.

Observed Results:
The app does NOT get new didDiscover peripheral calls after scanForPeripherals was called when UIApplicationDidBecomeActive was fired.

Version:
iOS 11 Beta 1 (15A5278f)
iPhone 6 (Model: NG4A2ZD/A)

Notes:
A sample project is attached with a video that shows the issue in action. The bug is not always reproducible.

Configuration:
The circumstances that show the bug are random and not clear.