Add test for setting shape source to nil from mapViewRegionIsChanging

2 files changed, 61 insertions, 5 deletions

diff --git a/platform/ios/Integration Tests/MBShapeSourceTests.m b/platform/ios/Integration Tests/MBShapeSourceTests.m
index 20a325af46..6a5c2942e4 100644
--- a/platform/ios/Integration Tests/MBShapeSourceTests.m
+++ b/platform/ios/Integration Tests/MBShapeSourceTests.m
@@ -13,7 +13,7 @@
 
 @implementation MBShapeSourceTests
 
-- (void)testRepeatedlyChangingShapeSourceToNil {
+- (void)testSettingShapeSourceToNilInRegionDidChange {
 
     NSMutableArray *features = [[NSMutableArray alloc] init];
 
@@ -38,7 +38,7 @@
     XCTestExpectation *expectation = [self expectationWithDescription:@"regionDidChange expectation"];
 
     __weak typeof(self) weakself = self;
-    __block NSInteger delegateCallCount;
+    __block NSInteger delegateCallCount = 0;
 
     self.regionDidChange = ^(MGLMapView *mapView, BOOL animated) {
 
@@ -56,7 +56,7 @@
         // See https://github.com/mapbox/mapbox-gl-native/issues/11180
 
         if (delegateCallCount > 10) {
-            XCTFail();
+            TestFailWithSelf(strongSelf);
         }
         else {
             shapeSource.shape = nil;
@@ -70,5 +70,57 @@
     [self waitForExpectations:@[expectation] timeout:30.0];
 }
 
+- (void)testSettingShapeSourceToNilInRegionIsChanging {
+
+    NSMutableArray *features = [[NSMutableArray alloc] init];
+
+    for (NSUInteger i = 0; i <= 180; i+=5) {
+        CLLocationCoordinate2D coord[4] = {
+            CLLocationCoordinate2DMake(round(0), round(i)),
+            CLLocationCoordinate2DMake(round(20), round(i)),
+            CLLocationCoordinate2DMake(round(0), round(i / 2 )),
+            CLLocationCoordinate2DMake(round(20), round(i / 2))};
+
+        MGLPolygonFeature *feature = [MGLPolygonFeature polygonWithCoordinates:coord count:4];
+        [features addObject:feature];
+    }
+
+    MGLShapeSource *shapeSource = [[MGLShapeSource alloc] initWithIdentifier:@"source" features:features options:nil];
+    [self.style addSource:shapeSource];
+
+    MGLFillStyleLayer *layer = [[MGLFillStyleLayer alloc] initWithIdentifier:@"layer" source:shapeSource];
+    layer.fillOpacity = [NSExpression expressionForConstantValue:@0.5];
+    [self.style addLayer:layer];
+
+    XCTestExpectation *expectation = [self expectationWithDescription:@"regionDidChange expectation"];
+
+    __block NSInteger delegateCallCount = 0;
+    __weak typeof(self) weakself = self;
+
+    self.regionIsChanging = ^(MGLMapView *mapView) {
+        // Setting the shapeSource.shape = nil, was causing an infinite loop, so here
+        // we check for a runaway call. 10 here is arbitrary. We could argue that this
+        // should check that the call count is only 1, however in this case we particularly
+        // want to check for the infinite loop.
+        // See https://github.com/mapbox/mapbox-gl-native/issues/11180
+        shapeSource.shape = nil;
+    };
+
+    self.regionDidChange = ^(MGLMapView *mapView, BOOL animated) {
+
+        delegateCallCount++;
+
+        if (delegateCallCount > 1) {
+            TestFailWithSelf(weakself);
+        }
+
+        [NSObject cancelPreviousPerformRequestsWithTarget:expectation selector:@selector(fulfill) object:nil];
+        [expectation performSelector:@selector(fulfill) withObject:nil afterDelay:1.0];
+    };
+
+    [self.mapView setCenterCoordinate:CLLocationCoordinate2DMake(10.0, 10.0) animated:YES];
+    [self waitForExpectations:@[expectation] timeout:30.0];
+}
+
 
 @end
diff --git a/src/mbgl/map/transform.cpp b/src/mbgl/map/transform.cpp
index f85272929f..07e54d33bd 100644
--- a/src/mbgl/map/transform.cpp
+++ b/src/mbgl/map/transform.cpp
@@ -628,8 +628,12 @@ bool Transform::inTransition() const {
 }
 
 void Transform::updateTransitions(const TimePoint& now) {
-    if (transitionFrameFn) {
-        transitionFrameFn(now);
+    auto transition = transitionFrameFn;
+    transitionFrameFn = nullptr;
+
+    if (transition) {
+        transition(now);
+        transitionFrameFn = transition;
     }
 }