Open Radar

 
Summary:
Setting CLLocationManager.headingOrientation to its existing value will trigger all of the same behaviors (e.g., a new heading update in -[CLLocationManagerDelegate locationManager:didUpdateHeading:]) as if the value had changed. This negates CLLocationManager.headingFilter if a developer attempts to set CLLocationManager.headingOrientation rapidly.

Steps to Reproduce:
1. Enable heading updates in a location manager and configure its delegate.
2. Set CLLocationManager.headingFilter to a large value, e.g., 10°. (Optional, makes it more obvious that the filter is ignored.)
3. Set CLLocationManager.headingOrientation to its existing value rapidly — several times a second, perhaps.
4. Observe heading updates in -[CLLocationManagerDelegate locationManager:didUpdateHeading:].

See attached demo project.

Expected Results:
CLLocationManager.headingOrientation would ignore being set to its existing value. No new heading event would be sent to its delegate.

Actual Results:
CLLocationManager.headingOrientation’s setter accepts the existing value and triggers its update behaviors, such as sending a new heading update to its delegate.

While sending a heading update when CLLocationManager.headingOrientation actually changes is desirable, doing this when there is effectively no change is not. If CLLocationManager.headingOrientation is set rapidly, heading updates will be sent/received at that same frequency and CLLocationManager.headingFilter will effectively be ignored.

Version:
10.3.1

Notes:
Workaround: check that you’re not setting CLLocationManager.headingOrientation to its existing value before you set it.

In the wild: https://github.com/mapbox/mapbox-gl-native/pull/9845