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Re: [Public WebGL] Problem with typed arrays in firefox



FYI, I've updated sdk/tests/conformance/array-unit-tests.html in the
WebGL public repository with a test case based on this report,
currently failing in Chromium and WebKit.

-Ken

On Wed, Oct 13, 2010 at 2:29 PM, Kenneth Russell <kbr@google.com> wrote:
> It's definitely a bug in Chrome / WebKit. Alan, could you please
> create an account on bugs.webkit.org and file it? Component WebGL, and
> CC: my email address. Or let me know if you would prefer I do it.
>
> -Ken
>
> On Wed, Oct 13, 2010 at 2:18 PM, Vladimir Vukicevic
> <vladimir@mozilla.com> wrote:
>>
>> That seems correct to me, and Chrome might have the bug -- a 29/30/31-byte ArrayBuffer can't be evenly divided into 4-byte Unit32 segments.  The spec states:
>>
>>> The given byteOffset must be a multiple of the element size of
>>> the specific type, otherwise an exception is raised.
>>>
>>> If a given byteOffset and length references an area beyond the
>>> end of the ArrayBuffer an exception is raised.
>>>
>>> If length is not explicitly specified, the length of the ArrayBuffer
>>> minus the byteOffset must be a multiple of the element size of the
>>> specific type, or an exception is raised.
>>
>> byteOffset is 0 if it isn't specified, so the third clause here applies in both cases.  The 0,4 case succeeds, because an explicit offset and length is given -- the resulting Uint32Array will have length 4, where 4*4=16 is less than 29/30/31 so that will succeed.
>>
>>    - Vlad
>>
>> ----- Original Message -----
>>> I think this may be a bug - if so I'll file a bug report.
>>>
>>> With firefox 4.b6 on win 7 x64 I'm seeing the following behavior:
>>>
>>> function testCase(size) {
>>> ab = new ArrayBuffer(size);
>>> try {
>>> var xyz = new Uint32Array(ab);
>>> } catch(err) {
>>> debug("!" + err + " no args");
>>> }
>>> try {
>>> var xyz = new Uint32Array(ab, 0);
>>> } catch(err) {
>>> debug("!" + err + " start");
>>> }
>>> try {
>>> var xyz = new Uint32Array(ab,0,4);
>>> } catch(err) {
>>> debug("!" + err + " start, offset");
>>> }
>>>
>>> }
>>>
>>> gives if size is not a multiple of 4. For example:
>>> !Error: invalid arguments no args
>>> !Error: invalid arguments start
>>>
>>> testCase(28); // OK
>>> testCase(29); // FAILS
>>> testCase(30); //FAILS
>>> testCase(31); // FAILS
>>> testCase(32); //OK
>>>
>>> This applies to ff b6 win 7 x64. Chrome works fine. I've tried the
>>> latest build but it crashes as
>>> soon as I open it.
>>>
>>> Thanks
>>>
>>> Alan
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
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