Comment 1 for bug 1647841

Thanks! Bug was there since last September, when I changed the frame of reference from center coords with width and height to a rectangle defined by left, top, right, and bottom. "Right" is not just left + width, but left + width - 1, because the rightmost cell is included. I forgot the - 1, also for the height, thus the area of effect was one too large for both of them.