if (XQueryTree(display, root, &d1, &d2, &wins, &num)) {
for (i = 0; i < num; i++) {
if (!XGetWindowAttributes(display, wins[i], &wa)
if (XQueryTree(display, root, &d1, &d2, &wins, &num)) {
for (i = 0; i < num; i++) {
if (!XGetWindowAttributes(display, wins[i], &wa)