1123059 - Some other operations should use ES6 ToLength

Status: RESOLVED WORKSFORME

(Core :: JavaScript Engine, defect)

Description

[ziyunfei]

js> "123".split("2", -1)
["1", "3"] // should be []


js> re=/a/y;
/a/y
js> re.lastIndex = -1
-1
js> re.test("ab")
false // should be true
js> re.lastIndex
0 // should be 1


js> ((...arg) => arg.length).apply(null, {length: -1})
RangeError: arguments array passed to Function.prototype.apply is too large // should be 0

Comment 1

[Claude Pache]

(In reply to ziyunfei from comment #0)
> js> "123".split("2", -1)
> ["1", "3"] // should be []
> 

Should be ["1","3"] according to https://tc39.github.io/ecma262/#sec-string.prototype.split step 6. (IIRC, the spec reverted to the older semantics because arrays didn’t switch to ToLength.)

> 
> js> re=/a/y;
> /a/y
> js> re.lastIndex = -1
> -1
> js> re.test("ab")
> false // should be true

Works as expected (yields `true`) in current stable FF release.

> js> re.lastIndex
> 0 // should be 1
> 

Ditto.

> 
> js> ((...arg) => arg.length).apply(null, {length: -1})
> RangeError: arguments array passed to Function.prototype.apply is too large
> // should be 0

Ditto. Evaluates to `0` in current FF.

Comment 2

[Tom S]

I don't think there is any actual work left here. Otherwise just opens a bug with a concrete example. Thanks.

Comment 3

[Florian Scholz (Open Web Docs)]

Same for docs, file an issue if something needs updating on MDN for this still.