Issue #124, case 1: Added test for this case
Actual fix is in stx:libbasic, revision 3563e89f551b.
https://swing.fit.cvut.cz/projects/stx-jv/ticket/124#comment:19
/* XPM */
static char *ScrollDn_disabled.w95.9_xpm[] = {
/* width height ncolors chars_per_pixel */
"9 9 3 1",
/* colors */
"a c white",
"b c #808080",
"c c none",
/* pixels */
"ccccccccc",
"ccccccccc",
"ccccccccc",
"cbbbbbbbc",
"ccbbbbbac",
"cccbbbacc",
"ccccbaccc",
"ccccacccc",
"ccccccccc",
};