Look at a text component (JTextField/JTextArea) in any look and feel. Select some text. Notice that the flashing caret stops short of the bottom of the selection. This is quite ugly and particularly noticeable under Windows L&F. This also affects editable JComboBoxes.
This is a regression from fix for
5048771 Text caret visibility very poor in GTK Style L&F with high-contrast/large print
in Tiger. As part of this fix,
g.drawLine(r.x, r.y, r.x, r.y + r.height - 1);
was changed to
g.fillRect(r.x, r.y, paintWidth , r.height - 1);
The problem is, the former call paints a line of height (r.height), and the latter one a line of height (r.height-1).