Open Radar

 
Summary:
There are situations where a single -setRegion:animated: call to MKMapView doesn't suffice to perform the complete region change. The region is slightly changed towards the indicated destination region but not completely. A second call with the same parameters lets the mapView "finish" the region change to the destination region.

Example:
Map region A:
center: 38.376115, -78.178711
span: 31.535612, 28.125000

Map Region B:
center: 61.185625,-149.941406
span: 32.366016,56.250000


Steps to Reproduce:
[mapView setRegion:A];
[mapView setRegion:B animated:YES];

Expected Results:
Region B should be displayed.

Actual Results:
Region C (with the correct span but an incorrect center is displayed):
center: 61.185625/-130.605469
span: 40.511116/56.250000


Regression:
Bug occurs under at least iOS 4.3 - 5.1 beta.



Please see the attached demo project that reproduces the issue: http://d.pr/G321

Press "Move Back" first, then "Move". Then you have to press "Move" again in order to move the map region to the final destination.