[bug?] datatable._check_rows doesn't calculate accurate count?

Hi,

I just found an issue in function _check_rows of datatable:

				if (!result)
					result = { start:i, count:(end-start) };
				else {
					result.last = i;
					result.count = (i-start);
				}

setting: page size = 40, datafetch = 60, click page 1->2->3->4 …
then the function will calculate below results:

start    last     count
60       99       59
120     179     59
180     219     59

If I understand properly, the correct results should be:

start    last     count
60       99       39
120     179     59
180     219     39

Maybe the line: result.count = (i-start);
should be result.count = (i-result.start); ?

It won’t make error because final loading will use datafetch (60).

Regards
Wicky