Index or size is negative or greater than the allowed amount

[niksy]

Firefox 8 (I know, it's old :D) throws error on this line: https://github.com/weblinc/picture/blob/master/picture.js#L163

[niksy]

As referenced in this issue, I have fixed the problem in my fork. If it's okay with you or you don't have any additional workaround for this, I can make pull request.

[knightdr]

@niksy

That sounds great, thanks.