Zhiyi Zhang (@zhiyi) commented about dlls/winex11.drv/window.c:
for (i = 0; i < NB_NET_WM_STATES; i++) {
if (!((old_state ^ new_state) & (1 << i))) continue;
This was removed specifically to fix a KDE bug. Please see c5ec1585f6e5211a2b63e3435748210552250534 for details.