Catch nil response

Author: NiklasMerz

src/ios/IONAssetHandler.m

@@ -61,19 +61,21 @@ - (void)webView:(WKWebView *)webView startURLSchemeTask:(id <WKURLSchemeTask>)ur
 
                 // set cookies to WKWebView
                 NSHTTPURLResponse *httpResponse = (NSHTTPURLResponse*)response;
-                NSArray* cookies = [NSHTTPCookie cookiesWithResponseHeaderFields:[httpResponse allHeaderFields] forURL:response.URL];
-                [[NSHTTPCookieStorage sharedHTTPCookieStorage] setCookies:cookies forURL:httpResponse.URL mainDocumentURL:nil];
-                cookies = [[NSHTTPCookieStorage sharedHTTPCookieStorage] cookies];
-                
-                for (NSHTTPCookie* c in cookies)
-                {
-                    dispatch_async(dispatch_get_global_queue( DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^(void){
-                        //running in background thread is necessary because setCookie otherwise fails
-                        dispatch_async(dispatch_get_main_queue(), ^(void){
-                            [cookieStore setCookie:c completionHandler:nil];
+                if(httpResponse) {
+                    NSArray* cookies = [NSHTTPCookie cookiesWithResponseHeaderFields:[httpResponse allHeaderFields] forURL:response.URL];
+                    [[NSHTTPCookieStorage sharedHTTPCookieStorage] setCookies:cookies forURL:httpResponse.URL mainDocumentURL:nil];
+                    cookies = [[NSHTTPCookieStorage sharedHTTPCookieStorage] cookies];
+                    
+                    for (NSHTTPCookie* c in cookies)
+                    {
+                        dispatch_async(dispatch_get_global_queue( DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^(void){
+                            //running in background thread is necessary because setCookie otherwise fails
+                            dispatch_async(dispatch_get_main_queue(), ^(void){
+                                [cookieStore setCookie:c completionHandler:nil];
+                            });
                         });
-                    });
-                };
+                    };
+                }
 
                 [urlSchemeTask didReceiveResponse:response];
                 [urlSchemeTask didReceiveData:data];