Review request for JDK-8068872: Nashorn JSON.parse drops numeric keys

Hannes Wallnoefer hannes.wallnoefer at
Thu Feb 5 10:05:36 UTC 2015

Yes, test262 and octane run fine.

One pecularity I found is that ensure(newIndex) usually only needs to be 
called if newIndex >= length. But this is not true for SparseArray, as 
newIndex may be smaller than the sparse array's length but still greater 
than the underlying dense array's length/capacity. SparseArray handles 
this by calling its ensure method in various places where other 
ArrayData classes don't.

Now that I think of it I will add a comment about this to 


Am 2015-02-05 um 10:55 schrieb Attila Szegedi:
> +1, looks good. Array handling can have sensitive corner cases - I presume you've run octane and test262 on this? Will also be curious about Marcus' review (he dealt a lot with arrays in the past).
> On Feb 5, 2015, at 10:48 AM, Hannes Wallnoefer <hannes.wallnoefer at> wrote:
>> Please review JDK-8068872: Nashorn JSON.parse drops numeric keys:
>> The main issue here was that ArrayData.ensure should only update the length if the new index is greater or equal to the old length.
>> I also fixed two other related issues:
>> - ScriptObject.defineProperty(int, Object) must call doesNotHaveEnsureDelete (which marks new unused slots as deleted) after having called ensure.
>> - There's no need to call ensure(length - 1) on a newly created ArrayData(length). I've removed two such cases.
>> Thanks,
>> Hannes

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