HelenOS sources

font_edit_adjust_underline_y0  351 uspace/app/fontedit/fontedit.c 		font_edit_adjust_underline_y0(fedit, -1);
font_edit_adjust_underline_y0  354 uspace/app/fontedit/fontedit.c 		font_edit_adjust_underline_y0(fedit, +1);
HelenOS homepage, sources at GitHub