Tested on iPhone iOS 10, macOS Sierra v10.12.6
Safari v10.1.2 (Safari v10.1.1 and below don't seem to have this problem, and neither do Chrome nor Firefox)
We're having a problem saving a photo through Google Cloud Storage. From the web inspector, we see that we're making a OPTIONS request to http://storage.googleapis.com/..., but we don't receive any response. Whereas, in other browsers or in other versions of Safari, we don't see a OPTIONS request, only the POST request. We've verified that our CORS configuration on the Google Cloud Storage bucket allows our origin.
Our request headers for the OPTIONS request look like this:
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6) AppleWebKit/603.3.8 (KHTML, like Gecko) Version/10.1.2 Safari/603.3.8
These are the errors in the console:
http://storage.googleapis.com/... Failed to load resource: Origin <origin> is not allowed by Access-Control-Allow-Origin
XMLHttpRequest cannot load http://storage.googleapis.com/... Origin <origin> is not allowed by Access-Control-Allow-Origin.
Is there a issue with the latest version of Safari and CORS?