Core Menu Icons disappeared in WordPress 6.9 RC1 using Safari Browser 15.6.1

[60885] used the modern alternative text for CSS content, which Safari did not support before 17.4.
​https://caniuse.com/mdn-css_properties_content_alt_text

Should we close this ticket as wontfix? The Core Handbook lists "Last 2 Safari versions." as the browser support.

​https://make.wordpress.org/core/handbook/best-practices/browser-support/

cc @joedolson

That's an interesting question. The browser support does say last two browser versions, but we've been ambiguous about what that means in a broader sense. I've generally interpreted that as the WordPress Admin, and external use should be treated separately.

Which means that with *this* specific issue, we should consider this as a wontfix, but should perhaps reconsider the global changes I made to dashicons, which will impact any use of the dashicons classes by any theme or plugin.

The commit included changes that are specific to admin uses, but I'd potentially want to revert the changes to dashicons.css.

@codex-m small request for the future, please upload the images directly to Trac. If an external image hosting site shuts down, this ensures that the images are always accessible in the future.

I did a bit of research to try and decide if we should revert this change. Here's what I found.

I looked into finding some usage statistics for Safari 15.6.x. Usage seems to sit at 0.167% according to the caniuse-db package, which is accessible ​visually through this site.

I then looked at the which version of MacOS was blocked from upgrading past this version of Safari, and that is a more complicated question. Statcounter's ​desktop MacOS version page has a large note at the top:

Apple are incorrectly reporting all macOS releases since Catalina 10.15 as Catalina 10.15. You can read more about it here.
We can't correctly show usage for Catalina 10.15, Big Sur 11, Monterey 12, Ventura 13 or Sonoma 14 until Apple fixes this.

I next tried to find statistics for iOS versions, and which devices were blocked from updating to newer version of Safari. Wikipedia has this:

iOS 15 is the final version of iOS that supports the iPhone 6s & 6s Plus, first-generation iPhone SE, iPhone 7 & 7 Plus, and seventh-generation iPod Touch, as its successor, iOS 16, drops support for those models.

I couldn't find good data about the percentage number of iOS devices by type, but ​I found iOS version data. Based on this, ~5.4% of all iOS traffic is on a 15.x version of iOS.

I don't think we can reasonably rely on the data here and have to assume that there is 5-8% usage to be conservative. When applied to WordPress at scale, just 5% is millions of sites.

Another aspect to this is that the Classic Editor uses Dashicons for the TinyMCE buttons. If the Dashicons font is broken, then that is completely unusable.

Given all this, I think that reverting the changes to dashicons.css for 6.9 makes the most sense to me.

I'll take care of the partial revert covering the changes in dashicons.css, @desrosj. I agree with your logic.

The changes will still impact some cases, because we're not talking about reverting all admin changes, but will remove the impact that is outside of WordPress core usage.

And yes, I really wish that Safari versioning was a little easier to research...such a mess!

This will prevent plugins and themes that require dashicons.css from breaking support for older Safari versions.

For clarity, this does *not* resolve the issue reported in the related ticket; core menu icons will still be missing in unsupported Safari browsers. But it will prevent this issue from expanding to 3rd party applications that require dashicons.css as a dependency.

Trac ticket: https://core.trac.wordpress.org/ticket/64266

This was reviewed in the 6.9 bug scrub and it was felt that because this change reverts to a previous state, we can remove the needs-testing keyword and move forward.

In 61290:

Reopening for backport to the 6.9 branch.

[61290] looks good to backport, @joedolson!

In 61293: