This post is an effort to draw attention to a regression in Tahoe that has a large impact on our app. This bug was filed during seed 3 but remains open:
FB18869578: Regression: WebView fails to render fonts registered with CTFontManagerRegisterFontURLs or ATSApplicationFontsPath
The gist of it is that WKWebView fails to render text that is styled with a “font-family” that references a font that has been loaded into the app using either the ATSApplicationFontsPath Info.plist key or loaded dynamically with CTFontManagerRegisterFontURLs. The area where the text should be is just blank.
There is more detail and a reproducer in the bug referenced above. We really hope this bug can get fixed before GA.
If anyone else would like to try and reproduce it, you can download a test case from here: https://e3supportuploads.s3-accelerate.amazonaws.com/8739959ce24de40fa462798a532aaa99fbfc9affba4f2a3e71d397f9e30d2604