v0.9.2: fixed rare vfx issues with barkskin buff icon

core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/actors/buffs/Barkskin.java

@@ -75,7 +75,7 @@ public class Barkskin extends Buff {
 	public float iconFadePercent() {
 		if (target instanceof Hero){
 			float max = ((Hero) target).lvl;
-			return (max-level)/max;
+			return Math.max(0, (max-level)/max);
 		}
 		return 0;
 	}