JavaScript engine quietly fails in Safari and WKWebView if certain function names are used

Any page that has a JavaScript function named "top()" in it causes JavaScript to fail. The function doesn't need to be called or even contain anything.

eg.

function top() 
{
} 

JavaScript just locks up. This affects iOS17.2 and macOS 14.2 If occurs in Safari and any app using WKWebView

This is a critical bug that affects sites and apps in the wild. I suggest there is something very wrong with the Javascript engine in general if certain function names can cause such a failure.

Does anyone else have other function names that cause this failure?

Replies

Fixed in iOS17.4 beta 4