commit 27b0142203e06bdbb1ff3c2179ac88e08aa4295e
from: garbeam@gmail.com <unknown>
date: Sat Jul  2 09:02:22 2011 UTC

applied Garys patch in a slightly modified way

commit - 867ba360300682859ab963222ec0a3f42586ff54
commit + 27b0142203e06bdbb1ff3c2179ac88e08aa4295e
blob - f842b419221e698e6ba0bac919b4f3b74bb9a990
blob + ba00afeb6aa87666837e467bf788393cc73d002a
--- dwm.c
+++ dwm.c
@@ -529,7 +529,7 @@ clientmessage(XEvent *e) {
 	if(!c)
 		return;
 	if(cme->message_type == netatom[NetWMState] && cme->data.l[1] == netatom[NetWMFullscreen]) {
-		if(cme->data.l[0]) {
+		if(cme->data.l[0] && !c->isfullscreen) {
 			XChangeProperty(dpy, cme->window, netatom[NetWMState], XA_ATOM, 32,
 			                PropModeReplace, (unsigned char*)&netatom[NetWMFullscreen], 1);
 			c->isfullscreen = True;