Bug 213726 – fetch fails only when site/pwa is added to homescreen

• Status: NEW
• Component: New Bugs

I have a PWA (http://app.turath.io) that loads a JSON file from another subdomain.

This works fine in Safari iOS, but it fails once I add the site to homescreen.

The error message:
> Fetch API cannot load https://files.turath.io/data.json due to access control checks.
> Failed to load resource: Preflight response is not successful

This only recently broke.

[Hossameldin]

I have a similar situation 
Very important to fix

Note: I updated the service worker to ignore this fetch, and that *seems* to have fixed the issue.

If so, the bug is with the sw's proxying.


The change I made to the service worker:
 self.addEventListener('fetch', e => {
+    if (e.request.url === 'https://files.turath.io/data.json')
+        return;
     e.respondWith(caches.match(e.request).then(r => r || fetch(e.request)));
 });

[Radar WebKit Bug Importer]

<rdar://problem/65110679>