Open Radar

 
Summary:

When using a MKMapView to display a map with a type using sat-images (MKMapTypeSatellite or MKMapTypeHybrid) setting the displayed coordinate region to a region with smallest east/west or north/south distance smaller then 75 meters results in error tiles being rendered. On a device with a retina screen the distance may not be smaller then 150 meters. The device's screen type should not affect the minimum region which can ben shown without showing error tiles.

Steps to Reproduce:

Use the attached demo project or:

1. Create a MKMapView instance
2. Set the region of the map view to a region with a size shorter then 150 but lager then 75 meters. E.g.:
    double value = 80.0;
    CLLocationCoordinate2D center = CLLocationCoordinate2DMake(52.518611, 13.408056);
    MKCoordinateRegion region = MKCoordinateRegionMakeWithDistance(center, value, value);
    [self.mapView setRegion:region animated:YES];

3. Run the code on a retina and a non-retina device. 


Expected Results:

On all devices see a satellite photo in the background of the map. 

Actual Results:

On the retina device you see a grey error tile as the map background.
On the non-retina device you see a satellite photo as the map background. 

Regression:

This bug does not exist on iOS 5.x

Notes:

The error tile behavior is not documented anywhere. Neither is the threshold after which an error tile is shown. In my opinion either a minimum zoom level should be enforced by the MKMapView or the most detailed availible tiles should be zoomed even if this means pixelated map background.