coordsAtPos is underspecified at line wrap points

[marijnh]

If you call coordsAtPos on a position that lies exactly at the point where a line is wrapped, there's two rectangles that can reasonably be returned for that position—the end of the first line or the start of the second line. Fixing this would probably involve adding an argument to coordsAtPos to specific which side of the position you are interested in (after or before).

[marijnh]

The same thing happens on bidi text 'jump' points where the direction of the text flips.