ssia
Created attachment 464695 [details] Patch
Created attachment 464697 [details] Patch
Looks like this needs some rebaselining.
Created attachment 464700 [details] Patch
Created attachment 464746 [details] Patch
<rdar://problem/105026066>
Safari Technology Preview 181 is passing all these tests: https://wpt.fyi/results/css/css-text/white-space?label=master&label=experimental&aligned&q=css%2Fcss-text%2Fwhite-space%2Ftab-stop-threshold
Progressed with this: https://github.com/WebKit/WebKit/commit/d88306bc080b632ff421d82f64806ca1220fe9ab
It's a bit odd to have this inline layout functionality in FontCascade, but as long as those tests are fixed...