fix bug 1221750 - Simplify dirtiness checking
fix bug 1221750 - Simplify dirtiness checking

jezdez/kuma,openjck/kuma,a2sheppy/kuma,openjck/kuma,escattone/kuma,a2sheppy/kuma,ollie314/kuma,SphinxKnight/kuma,anaran/kuma,mozilla/kuma,anaran/kuma,SphinxKnight/kuma,ollie314/kuma,ollie314/kuma,anaran/kuma,yfdyh000/kuma,jezdez/kuma,jgmize/kuma,a2sheppy/kuma,darkwing/kuma,safwanrahman/kuma,anaran/kuma,mozilla/kuma,ollie314/kuma,safwanrahman/kuma,jwhitlock/kuma,jgmize/kuma,openjck/kuma,escattone/kuma,jwhitlock/kuma,SphinxKnight/kuma,openjck/kuma,jezdez/kuma,jwhitlock/kuma,jgmize/kuma,darkwing/kuma,SphinxKnight/kuma,safwanrahman/kuma,yfdyh000/kuma,jwhitlock/kuma,darkwing/kuma,anaran/kuma,Elchi3/kuma,mozilla/kuma,yfdyh000/kuma,Elchi3/kuma,jezdez/kuma,SphinxKnight/kuma,safwanrahman/kuma,Elchi3/kuma,darkwing/kuma,yfdyh000/kuma,safwanrahman/kuma,safwanrahman/kuma,darkwing/kuma,SphinxKnight/kuma,ollie314/kuma,jgmize/kuma,mozilla/kuma,a2sheppy/kuma,Elchi3/kuma,ollie314/kuma,openjck/kuma,darkwing/kuma,escattone/kuma,openjck/kuma,anaran/kuma,jgmize/kuma,Elchi3/kuma,jgmize/kuma,a2sheppy/kuma,jezdez/kuma,jwhitlock/kuma,yfdyh000/kuma,mozilla/kuma,jezdez/kuma,yfdyh000/kuma