My Sites: Fall back to plain favicon when no Site Icon is present

[wprashed]

Summary

Fixes #114.

Sites recorded through wp-admin alone, or themes that hardcode a plain favicon instead of utilizing WordPress Site Icon markup, do not have a stored iconUrl in their My Sites record and previously displayed the fallback globe icon permanently.

Changes

• In MySiteRow (src/popup/components/MySites.js), if site.iconUrl is not present, attempt to render the site's standard ${origin}/favicon.ico.
• If an onError event fires for the active icon, fallback to ${origin}/favicon.ico (if attempting a custom icon) or the globe icon when no favicon can be loaded.
• Rebuilt popup production bundles and synced Safari resources.

Testing Instructions

1. Run npm test or node test/smoke.js.
2. In the popup, inspect a My Sites row for a site without an explicit Site Icon URL and verify it attempts loading ${origin}/favicon.ico before falling back to the globe icon.

[i-am-chitti]

Thanks for picking it up. I gone through the changes and here are two notes. Not a maintainer here, so please read these as suggestions rather than blockers.

• 10up.com, the example in #114, is not be covered completely: its /favicon.ico returns an nginx 404 currently, and the real icon sits at a theme path in <link rel="shortcut icon">. It does emit an apple-touch-icon, which detect.js already accepts (L123-L125), so that row may fill in on its own after one logged-in front-end visit.

[i-am-chitti]

Since origin drops the install path, two installs on one host - example.com/client1 and example.com/client2 - would both request https://example.com/favicon.ico, and a subdirectory multisite child would pick up the main site's icon. Records are keyed at the install base for that reason (#94), so would baseUrl from 73 fit better here? It's always set (site.baseUrl || origin), so the guard could go with it:

Suggested change

	const defaultFavicon = origin ? `${origin}/favicon.ico` : null;
	const defaultFavicon = `${baseUrl}/favicon.ico`;

For subdirectory installs that mostly falls through to the globe rather than finding an icon - core registers the favicon.ico rewrite only when the install is at the domain root - though that seems kinder than showing a different site's icon.

[i-am-chitti]

this copies a prop into state, and the initializer only runs once. Rows keep their instance across store updates (keyed by site.key, L44), so if a later login captures the Site Icon through upsertOnLogin, the row re-renders while activeIcon still holds the old URL. The new icon would then appear only after the popup is reopened. iconFailed behaves the same way.

A reset covers both:

useEffect(() => { setActiveIcon(iconUrl || defaultFavicon); setIconFailed(false); }, [iconUrl, defaultFavicon]);

[wprashed]

Thanks for the review and note, @i-am-chitti! Exactly as you pointed out, for sites with apple-touch-icon or standard sized Site Icon markup, detect.js captures siteIconUrl on front-end visits. For sites recorded purely via wp-admin or without sized icon links, trying /favicon.ico at render time provides a display-only best-effort fallback before showing the globe icon, keeping detection and storage untouched as outlined in #114.

[Xilonz]

@wprashed you can also try to get the favicon directly from the browser: https://developer.chrome.com/docs/extensions/how-to/ui/favicons