Charable
if (WINDOW_EXT(win, addch_used) != 0 || !Charable(ch)) {
!Charable(new_bkgd)) {
if (Charable(new_bkgd)) {
if (Charable(ch)) { \
|| !Charable(ch)
} else if (SP_PARM != 0 && Charable(*wc)) {