improve Columns.get_cursor_coords() test to expose second regression
improve Columns.get_cursor_coords() test to expose second regression

rndusr/urwid,westurner/urwid,Julian/urwid,wardi/urwid,foreni-packages/urwid,hkoof/urwid,harlowja/urwid,Julian/urwid,urwid/urwid,drestebon/urwid,zyga/urwid,tonycpsu/urwid,mountainstorm/urwid,douglas-larocca/urwid,zyga/urwid,urwid/urwid,harlowja/urwid,westurner/urwid,urwid/urwid,Julian/urwid,rndusr/urwid,rndusr/urwid,zyga/urwid,tonycpsu/urwid,ivanov/urwid,bk2204/urwid,hkoof/urwid,inducer/urwid,harlowja/urwid,inducer/urwid,mountainstorm/urwid,bk2204/urwid,hkoof/urwid,foreni-packages/urwid,bk2204/urwid,wardi/urwid,drestebon/urwid,douglas-larocca/urwid,drestebon/urwid,ivanov/urwid,inducer/urwid,tonycpsu/urwid,ivanov/urwid,foreni-packages/urwid,mountainstorm/urwid,westurner/urwid,wardi/urwid,douglas-larocca/urwid