only use old size if floating

dwm.c

@@ -1571,12 +1571,14 @@ setfullscreen(Client *c, int fullscreen)
 			PropModeReplace, (unsigned char*)0, 0);
 		c->isfullscreen = 0;
 		c->isfloating = c->oldstate;
+		if(c->isfloating){
 			c->bw = c->oldbw;
 			c->x = c->oldx;
 			c->y = c->oldy;
 			c->w = c->oldw;
 			c->h = c->oldh;
 			resizeclient(c, c->x, c->y, c->w, c->h);
+		}
 		arrange(c->mon);
 	}
 }