Missing icons in top admin-bar and visual editor for older browsers (firefox 115)

[timholz]

Since wordpress 6.9 icons in the admin-bar at the top and also in the visual editor are missing.
The auto generated admin-bar-rtl.min.css for instance has no effect.
I compared with chrome version 116.0.5845.187. This browser works well.

[timholz]

Admin-bar: WP-Logo at the top left, the home-icon, the comment icon and the plus icon.
Visual editor: all icons

[ocean90]

Related: ​https://blog.mozilla.org/futurereleases/2025/09/04/firefox-esr-115-support-for-windows-7-8-and-8-1-and-old-mac-os-versions-extended-until-march-2026/

Probably introduced by [60885] which already had a partial revert with [61293].

[sabernhardt]

Both [60885] and [60806] employed the newer syntax to set empty alternative text for icons in the admin toolbar (and other places such as the Classic Editor).

As @jorbin said in comment:12:ticket:64350 regarding checkboxes,

There is a clear workaround to this issue: Use a browser that WordPress supports.

Based on this clearly falling outside of the current browser support policy and this ticket not being the best place to decide a change to that policy, I think this should be closed as maybelater with the maybe being based on the browser support policy changing at some point in the future.

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The partial revert in [61293] was for the dashicons stylesheet itself, because it could be enqueued on the front end. The admin toolbar also appears on the front end for logged-in users, though that is still within the context of WordPress administration and accessing user profiles.

On the other hand, the lack of icons in old browsers can make the About WP menu and Search box very difficult to discover on larger screens, and the toolbar requires icons at sizes narrower than 782 pixels (or zoom equivalent).

[sabernhardt]

#64350 has a patch now to add the old values as a fallback for icons, including those used in the admin toolbar and Classic Editor buttons.

[timholz]

Great!!!