miscoded

Prototype 1.5.0 completely breaks CNN on certain mobile versions of Opera. All the text disappears.

We've dug up the source and it appears to be code from the common prototype.js that causes problems, CNN's prototype.js is here:

Element.extend.cache = {
  findOrStore: function(value) {
    return this[value] = this[value] || function() {
      return value.apply(null, [this].concat($A(arguments)));
    }
  }
};

Problem arises when the "value" argument is a function object. Then this[value] = this[value] requires decompilation, in order to create a string for the property name.

This is a bad idea because

• Decompilation support is an optional feature. We disable it on many limited platforms for performance
  
• Decompiling a function is in any case not a reliable way to create a unique hash key since functions can have exactly the same source code but live in different scopes or different closures, so this code as-is will create obscure bugs that are very hard to track down.
  

I hope the excellent Prototype devs can find a better approach. Unfortunately this code is still there in the latest version.

(Due to impatient family members I can't bug it in their tracker right now, post a link to the bug in comments if you do.)