Bug 113425 – Structured clone does not preserve array lengths

• Status: NEW
• Component: New Bugs

[Elliott Sprehn]

ex.

postMessage(new Array(10), '*');
onmessage = function(event) {
  console.log(event.data.length); // should be 10, but 0 in webkit.
});

[Elliott Sprehn]

Relevant spec text:

http://www.w3.org/html/wg/drafts/html/master/infrastructure.html#safe-passing-of-structured-data

If input is an Array object
   Let output be a newly constructed empty Array object whose length is equal to the length of input.

   This means that the length of sparse arrays is preserved.

[Elliott Sprehn]

This looks like a one line fix for v8:

virtual bool completeSparseArray(uint32_t numProperties, uint32_t length, v8::Handle<v8::Value>* value)

has array = v8::Array::New();

and completely ignores the length value. We should do ::New(length) instead.