Don't stroke rectangles with height or width 0 in draw_round_box
dup
0.0 gt {
setlinewidth % w h x y
- 0 setlinecap
- 1 setlinejoin
-
rmoveto % w h
- currentpoint % w h x1 y1
- 4 2 roll % x1 y1 w h
- 4 copy
- rectfill
- rectstroke
+ 2 copy 0 ne exch 0 ne and
+ {
+ 0 setlinecap
+ 1 setlinejoin
+ currentpoint % w h x1 y1
+ 4 2 roll % x1 y1 w h
+ 4 copy
+ rectfill
+ rectstroke
+ } {
+ 1 setlinecap
+ rlineto stroke
+ } ifelse
} {
pop % w h x y
rmoveto % w h