Line Selection Issue

Hi,

I've found an issue with line selection when selecting multiple lines from the selection margin. The issue is that when doing a top-down selection, the first line selected is deselected (except for the CRLF) when the last line in the control is selected. When selecting from the bottom up, the CRLF in the last line is deselected when the mouse moves to select the prior line. I have only found this issue to occur when the last line in the control is part of the selection.