Fix crash in userLocationVerticalAlignment, analyzer warning (#5278)

* [ios] Fixed crash in userLocationVerticalAlignment

Avoid creating an array with nil.

Fixes #5274.

* [ios] Fixed analyzer warning

Fixed a write-without-read analyzer warning introduced in #5235.

2 files changed, 10 insertions, 5 deletions

diff --git a/platform/ios/CHANGELOG.md b/platform/ios/CHANGELOG.md
index 8c2eeca35f..fd176a9472 100644
--- a/platform/ios/CHANGELOG.md
+++ b/platform/ios/CHANGELOG.md
@@ -21,6 +21,7 @@ Mapbox welcomes participation and contributions from everyone.  Please read [CON
 - Fixed an issue preventing KVO change notifications from being generated on MGLMapView’s `userTrackingMode` key path when `-setUserTrackingMode:animated:` is called. ([#4724](https://github.com/mapbox/mapbox-gl-native/pull/4724))
 - Rendering now occurs on the main thread, fixing a hang when calling `-[MGLMapView styleURL]` before the map view has fully loaded or while the application is in the background. ([#2909](https://github.com/mapbox/mapbox-gl-native/pull/2909))
 - Improved responsiveness when zooming in then immediately panning around. ([#4595](https://github.com/mapbox/mapbox-gl-native/pull/4595))
+- Fixed a crash setting MGLMapView’s `userLocationVerticalAlignment` property before a user location update has occurred. ([#5274](https://github.com/mapbox/mapbox-gl-native/issues/5274))
 - Added category methods on NSValue for converting to and from the structure types defined in MGLGeometry.h. ([#4802](https://github.com/mapbox/mapbox-gl-native/pull/4802))
 - Added NSFormatter subclasses for converting geographic coordinates and directions into display strings. ([#4802](https://github.com/mapbox/mapbox-gl-native/pull/4802))
 - Added a new method, `-[MGLMapView cameraThatFitsCoordinateBounds:]`, to get a camera that you can pass into `-setCamera:` that fits the given coordinate bounds. ([#4790](https://github.com/mapbox/mapbox-gl-native/pull/4790))
diff --git a/platform/ios/src/MGLMapView.mm b/platform/ios/src/MGLMapView.mm
index bd8762c475..5d1bcb1109 100644
--- a/platform/ios/src/MGLMapView.mm
+++ b/platform/ios/src/MGLMapView.mm
@@ -2103,8 +2103,7 @@ mbgl::Duration MGLDurationInSeconds(NSTimeInterval duration)
     }
     
     std::sort(visibleAnnotations.begin(), visibleAnnotations.end());
-    auto foundElement = std::find(visibleAnnotations.begin(), visibleAnnotations.end(),
-                                  ((MGLAnnotationAccessibilityElement *)element).tag);
+    auto foundElement = std::find(visibleAnnotations.begin(), visibleAnnotations.end(), tag);
     if (foundElement == visibleAnnotations.end())
     {
         return NSNotFound;
@@ -3846,9 +3845,10 @@ mbgl::Duration MGLDurationInSeconds(NSTimeInterval duration)
 
             [self.locationManager stopUpdatingHeading];
 
-            if (self.userLocationAnnotationView)
+            CLLocation *location = self.userLocation.location;
+            if (location && self.userLocationAnnotationView)
             {
-                [self locationManager:self.locationManager didUpdateLocations:@[self.userLocation.location] animated:animated];
+                [self locationManager:self.locationManager didUpdateLocations:@[location] animated:animated];
             }
 
             break;
@@ -3896,7 +3896,11 @@ mbgl::Duration MGLDurationInSeconds(NSTimeInterval duration)
     _userLocationVerticalAlignment = alignment;
     if (self.userTrackingMode != MGLUserTrackingModeNone)
     {
-        [self locationManager:self.locationManager didUpdateLocations:@[self.userLocation.location] animated:animated];
+        CLLocation *location = self.userLocation.location;
+        if (location)
+        {
+            [self locationManager:self.locationManager didUpdateLocations:@[location] animated:animated];
+        }
     }
 }