onSuccess being called without an actual upload?

[ImOnMars]

I apologize for creating a couple of issues but I'm getting some odd behavior.

I'm using DirectUploadProvider and I have a callback set for onSuccess. On very first upload this works as intended, if I open the file choose dialog and then click Cancel it does nothing, but if I choose a file then it uploads it and returns to the onSuccess callback. But if I open the file dialog again to replace the existing file and then click Cancel instead of choosing a file, it calls the onSuccess callback again even though no file was chosen and there isn't any new requests.