fix(ios): fix broken ios code from #4354

Author: Salakar

packages/firebase_dynamic_links/ios/Classes/FLTFirebaseDynamicLinksPlugin.m

@@ -138,20 +138,18 @@ - (void)onDeepLinkResult:(FIRDynamicLink *_Nullable)dynamicLink error:(NSError *
   }
 }
 
-- (BOOL)checkForDynamicLink:(NSURL *)url {
+- (void)checkForDynamicLink:(NSURL *)url {
   FIRDynamicLink *dynamicLink = [[FIRDynamicLinks dynamicLinks] dynamicLinkFromCustomSchemeURL:url];
   if (dynamicLink) {
     [self onDeepLinkResult:dynamicLink error:nil];
-    return YES;
   }
-  return NO;
 }
 
 - (BOOL)application:(UIApplication *)application
             openURL:(NSURL *)url
             options:(NSDictionary<UIApplicationOpenURLOptionsKey, id> *)options {
   [self checkForDynamicLink:url];
-  // results of this are ORed and NO doesn't affect other delegate interceptors' result
+  // Results of this are ORed and NO doesn't affect other delegate interceptors' result.
   return NO;
 }
 
@@ -160,49 +158,48 @@ - (BOOL)application:(UIApplication *)application
     sourceApplication:(NSString *)sourceApplication
            annotation:(id)annotation {
   [self checkForDynamicLink:url];
-  // results of this are ORed and NO doesn't affect other delegate interceptors' result
+  // Results of this are ORed and NO doesn't affect other delegate interceptors' result.
   return NO;
 }
 
 - (BOOL)application:(UIApplication *)application
     continueUserActivity:(NSUserActivity *)userActivity
-      restorationHandler:
-#if defined(__IPHONE_12_0) && (__IPHONE_OS_VERSION_MAX_ALLOWED >= __IPHONE_12_0)
-          (nonnull void (^)(NSArray<id<UIUserActivityRestoring>> *_Nullable))restorationHandler {
-#else
-          (nonnull void (^)(NSArray *_Nullable))restorationHandler {
-#endif  // __IPHONE_12_0
+      restorationHandler:(nonnull void (^)(NSArray *_Nullable))restorationHandler {
   __block BOOL retried = NO;
+  void (^completionBlock)(FIRDynamicLink *_Nullable dynamicLink, NSError *_Nullable error);
+  void (^__block __weak weakCompletionBlock)(FIRDynamicLink *_Nullable dynamicLink,
+                                             NSError *_Nullable error);
+  weakCompletionBlock = completionBlock = ^(FIRDynamicLink *_Nullable dynamicLink,
+                                            NSError *_Nullable error) {
+    if (!error && dynamicLink && dynamicLink.url) {
+      [self onDeepLinkResult:dynamicLink error:nil];
+    }
 
-  id completion =
-      ^(FIRDynamicLink *_Nullable dynamicLink, NSError *_Nullable error) {
-        if (!error && dynamicLink && dynamicLink.url) {
-          [self onDeepLinkResult:dynamicLink error:nil];
-        }
-      }
-      // Per Apple Tech Support, a network failure could occur when returning from background on
-      // iOS 12. https://github.com/AFNetworking/AFNetworking/issues/4279#issuecomment-447108981 So
-      // we'll retry the request once
-      if (error && !retried && [NSPOSIXErrorDomain isEqualToString:error.domain] &&
-          error.code == 53) {
-    retried = YES;
-    [[FIRDynamicLinks dynamicLinks] handleUniversalLink:userActivity.webpageURL
-                                             completion:completion];
-  }
-  // We could send this to Dart and maybe have a onDynamicLinkError stream but there's also
-  // a good chance the `userActivity.webpageURL` might not be for a Firebase dynamic link,
-  // which needs consideration - so we'll log this for now, logging will get picked up by
-  // Crashlytics automatically if its integrated.
-  if (error)
-    NSLog(@"FLTFirebaseDynamicLinks: Unknown error occurred when attempting to handle a universal "
+    // Per Apple Tech Support, a network failure could occur when returning from background on
+    // iOS 12. https://github.com/AFNetworking/AFNetworking/issues/4279#issuecomment-447108981 So
+    // we'll retry the request once
+    if (error && !retried && [NSPOSIXErrorDomain isEqualToString:error.domain] &&
+        error.code == 53) {
+      retried = YES;
+      [[FIRDynamicLinks dynamicLinks] handleUniversalLink:userActivity.webpageURL
+                                               completion:weakCompletionBlock];
+    }
+    // We could send this to Dart and maybe have a onDynamicLinkError stream but there's also
+    // a good chance the `userActivity.webpageURL` might not be for a Firebase dynamic link,
+    // which needs consideration - so we'll log this for now, logging will get picked up by
+    // Crashlytics automatically if its integrated.
+    if (error)
+      NSLog(
+          @"FLTFirebaseDynamicLinks: Unknown error occurred when attempting to handle a universal "
           @"link: %@",
           error);
-};
+  };
 
-[[FIRDynamicLinks dynamicLinks] handleUniversalLink:userActivity.webpageURL completion:completion];
+  [[FIRDynamicLinks dynamicLinks] handleUniversalLink:userActivity.webpageURL
+                                           completion:completionBlock];
 
-// results of this are ORed and NO doesn't affect other delegate interceptors' result
-return NO;
+  // Results of this are ORed and NO doesn't affect other delegate interceptors' result.
+  return NO;
 }
 
 - (FIRDynamicLinkShortenerCompletion)createShortLinkCompletion:(FlutterResult)result {