ASTextNode2 incorrect layout for CJK language

[yxztj]

Looks very similar to facebookarchive/AsyncDisplayKit#2894, which has been fixed by delaying set NSTextStorage.setAttributedString in ASTextKitContext.

Now ASTextNode2 is not using TextKit(thus the previous fix is not applicable), but Core Text directly. Again the issue only happen when displaying CJK language. Haven't found a way to fix it now.

Setting the same attributedString on both ASTextNode(left) and ASTextNode2(right)

Fine with English:

It's simple to reproduce the issue:

let text = "哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈哈"
let attrText = NSAttributedString(string: text, attributes: [
    NSAttributedStringKey.font: UIFont.systemFont(ofSize: 16)
])
        
let node = ASTextNode()
node.attributedText = attrText
self.view.addSubview(node.view)
node.frame = CGRect(x: 20, y: 20, width: 150, height: 200)
        
let node2 = ASTextNode2()
node2.attributedText = attrText
self.view.addSubview(node2.view)
node2.frame = CGRect(x: 170, y: 20, width: 150, height: 200)

[JunyuKuang]

Have you found a way to work around this?

[JunyuKuang]

This seems to be a Core Text bug, and I filed a bug report (FB8270180) to Apple. They fixed it in iOS 14 beta 6.