Notifications using URIs instead of filenames for the app icon do not display correctly

[bluesabre]

Prerequisites

• [x] I have searched open and closed issues for duplicates.

Describe the bug

When a notification is sent with the app icon as a URI, it is not correctly displayed. This was observed using Google Chrome, where the app icon was "file:///tmp/.com.google.Chrome.rZmI2b". Instead of showing the Chrome icon, a image-missing icon was displayed instead.

To Reproduce

Steps to reproduce the behavior:

1. Using Google Chrome, navigate to https://www.bennish.net/web-notifications.html
2. Click the Authorize button to request web notifications.
3. Click the Show button to send a notification.
4. The notification is displayed with the site's image, overlaid with an image-missing icon.

Expected behavior

The notification should be overlaid with the application icon instead of a missing image.

Screenshots or screen recordings

Logs

Platform Information

elementary OS 6. Fully updated.

• [x] I'm using the latest version from git that I've manually compiled
• [ ] I'm using the latest released stable version

Additional context