Bug 135009 – assign undefined value to Element property throws TypeError

• Status: RESOLVED
• Resolution: DUPLICATE
• Component: DOM

[ShihChi Huang]

Prior to iOS8 Safari / Safari 8.0 if we assign undefined to Element property (like document.body.scrollTop) it fallback to 0

```js
document.body.scrollTop = undefined;

TypeError: Type error
column: 110
line: 1
message: "Type error"
stack: "eval code↵eval@[native code]↵_evaluateOn↵_evaluateAndWrap↵evaluate"
__proto__: Error
```

[Oliver Hunt]

Hmmm, this is complaining about assigning NaN (undefined is being number coerced)

Maybe due to fractional coordinates?

[Alexey Proskuryakov]

Good point. Can you still reproduce with a current WebKit nightly? I thought that the fractional coordinate change was already undone.

[Oliver Hunt]

I think this is a dupe of bug #134841

[ShihChi Huang]

awesome, I cannot repro in webkit nightly r171105

[alan]

(In reply to comment #2)
> Good point. Can you still reproduce with a current WebKit nightly? I thought that the fractional coordinate change was already undone.

It's been reverted only for Element.scroll*. Other properties' (Element.offset*, Element.client*) return type is still double.

*** This bug has been marked as a duplicate of bug 134841 ***