[ios] Defensive code for application delegate handling.

2 files changed, 23 insertions, 0 deletions

diff --git a/platform/ios/Integration Tests/MGLBackgroundIntegrationTest.m b/platform/ios/Integration Tests/MGLBackgroundIntegrationTest.m
index cea52740d2..b4d3eed4e8 100644
--- a/platform/ios/Integration Tests/MGLBackgroundIntegrationTest.m
+++ b/platform/ios/Integration Tests/MGLBackgroundIntegrationTest.m
@@ -53,6 +53,7 @@ typedef void (^MGLNotificationBlock)(NSNotification*);
     // Setup MGLMapView to use our new mocked application
     // Change notification handling here.
     self.oldApplication = self.mapView.application;
+    self.mockApplication.delegate = self.oldApplication.delegate;
     self.mapView.application = self.mockApplication;
 }
 
@@ -63,6 +64,7 @@ typedef void (^MGLNotificationBlock)(NSNotification*);
     // Swap back
     self.mapView.application = self.oldApplication;
     self.oldApplication = nil;
+    self.mockApplication.delegate = nil;
     self.mockApplication = nil;
     
     [super tearDown];
diff --git a/platform/ios/Integration Tests/MGLMockApplication.m b/platform/ios/Integration Tests/MGLMockApplication.m
index 3654e3ed54..06a8e173f1 100644
--- a/platform/ios/Integration Tests/MGLMockApplication.m
+++ b/platform/ios/Integration Tests/MGLMockApplication.m
@@ -8,6 +8,12 @@
 
 @implementation MGLMockApplication
 
+- (void)dealloc {
+    if (_delegate) {
+        CFRelease((CFTypeRef)_delegate);
+    }
+}
+
 - (instancetype)init {
     if ((self = [super init])) {
         _applicationState = UIApplicationStateActive;
@@ -32,6 +38,21 @@
     self.applicationState = UIApplicationStateActive;
 }
 
+- (void)setDelegate:(id<UIApplicationDelegate>)delegate {
+    // Property is `assign`, but we want to retain
+    if (_delegate != delegate) {
+        if (_delegate) {
+            CFRelease((CFTypeRef)_delegate);
+        }
+        
+        _delegate = delegate;
+
+        if (_delegate) {
+            CFRetain((CFTypeRef)_delegate);
+        }
+    }
+}
+
 - (BOOL)openURL:(NSURL*)url {
     TRACE();
     return NO;