Avoid potential integer overflow in QuickTimeVideo::userDataDecoder

[kevinbackhouse]

I'm worried about what will happen if size is between 1 and 11. I think it could cause an integer overflow.

[benmccann]

I might be missing something, but these seem exactly equivalent to me. That being said, I think the new version is written in a clearer manner

[kevinbackhouse]

I might be missing something, but these seem exactly equivalent to me. That being said, I think the new version is written in a clearer manner

@benmccann: the type of size is size_t which is unsigned, so if for example size == 5 then size - 12 will integer overflow and become a very large positive number, which means that this comparison won't work as intended.