Mapbox-gl-native: [iOS] Mapbox continuously asks for permission to access location on first launch.

[rweindl]

Platform: iOS (only on Device not in Simulator)
Mapbox SDK version: 3.7.4

Steps to trigger behavior

1. Configure the App to support MapBox and set NSLocationWhenInUseUsageDescription and NSLocationAlwaysUsageDescription in its Info.plist.
2. Instantiate a new MGLMapView.
3. Set showsUserLocation to true.

Expected behavior

When a user opens the map the first time I want the popup Allow "AppName" to access your location? to appear exactly once.

Actual behavior

When a user opens the map the first time the popup Allow "AppName" to access your location? appears in an infinite loop and I cannot tap any button like Only While Using the App, Always Allows or Don't Allow. The popup is visible for about 1 second and then reappears.

Workaround

Downgrading to version 3.7.3 solves the issue on our devices.

Screenshot

[friedbunny]

A few questions:

• Which iOS version(s) are you seeing this on?
• Which are you specifying: NSLocationAlwaysUsageDescription or NSLocationAlwaysAndWhenInUseUsageDescription? Both?
• Does the app a separate CLLocationManager that could be requesting permission?

[rweindl]

Hi @friedbunny thanks for taking such a quick look on that issue. To your questions:

• iOS Version is 11.2.5.
• Device is iPhone 6s / iPhone 7 and iPhone 8.
• Both NSLocationAlwaysUsageDescription and NSLocationAlwaysAndWhenInUseUsageDescription are specified.
• App is not using another CLLocationManager. The App also uses Firebase SDK which might use CLLocationManager in their SDK but this is only a hypothesis.

[friedbunny]

@rweindl Hrm, so I can’t reproduce this — neither by enabling showsUserLocation in viewDidLoad nor in a storyboard, with any combination of usage descriptions.

• Can you say more about how/where/when you instantiate the map view?
• Do you implement any of our location delegate methods or set any user location properties?

Oh, and if you have a test app that you can share that’d be greatly appreciated. 🙇

[captainbarbosa]

I can reproduce this with the Mapbox Studio Preview app.

[rweindl]

Hi @friedbunny I created a small test project for you illustrating this behavior. The only dependency is Mapbox 3.7.4. One note: The home button seems no longer to work as soon this behavior starts.

Execution:

1. pod install
2. Set MGLMapboxAccessToken in the Info.plist
3. Select a Developer Team to deploy on device.
4. Build on Device.

Zip File of the Test project:

MapBoxCrash.zip

Screenshot:

[friedbunny]

Thanks for your help @rweindl and @captainbarbosa — this is happening because #11151 re-added a listener for UIApplicationWillResignActiveNotification in 3.7.4.

After a bit of preliminary digging, it looks like this is the sequence of events leading to the loop:

• The app gets UIApplicationWillResignActiveNotification when the permission dialog appears.
• We catch the notification and call sleepGL:, which disables location services.
• The dialog disappears, because location services have been disabled and the permissions request effectively cancelled.
• With the dialog gone, the app gets UIApplicationDidBecomeActiveNotification and calls wakeGL:, which re-enables location services and asks for permission.

The quick fix would be to just remove the listener for UIApplicationWillResignActiveNotification (which we’ve evidently judged to be unnecessary in the past: https://github.com/mapbox/mapbox-gl-native/pull/2988), but perhaps we should also reevaluate wakeGL:/sleepGL:.

/cc @julianrex @1ec5 @akitchen @lilykaiser

[rweindl]

Thanks for identifying the issue that quickly and keeping us in the loop! We're using 3.7.3 in the meantime.

[friedbunny]

Fixed by #11229, which is now available in Mapbox Maps SDK for iOS 3.7.5. Thanks again for reporting this issue and helping us fix it, @rweindl. 🙇