v0.6.2c: fixed a variety of rare crash bugs

core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/actors/Actor.java

@@ -220,7 +220,7 @@ public abstract class Actor implements Bundlable {
 					current = null;
 				} else {
 					doNext = acting.act();
-					if (doNext && !Dungeon.hero.isAlive()) {
+					if (doNext && (Dungeon.hero == null || !Dungeon.hero.isAlive())) {
 						doNext = false;
 						current = null;
 					}

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

@@ -72,7 +72,7 @@ public class Buff extends Actor {
 	}
 	
 	public void detach() {
-		fx( false );
+		if (target.sprite != null) fx( false );
 		target.remove( this );
 	}
 	

core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/items/BrokenSeal.java

@@ -107,7 +107,7 @@ public class BrokenSeal extends Item {
 		private float partialShield;
 
 		@Override
-		public boolean act() {
+		public synchronized boolean act() {
 			if (armor == null) detach();
 			else if (armor.isEquipped((Hero)target)) {
 				if (target.SHLD < maxShield()){
@@ -122,11 +122,11 @@ public class BrokenSeal extends Item {
 			return true;
 		}
 
-		public void setArmor(Armor arm){
+		public synchronized void setArmor(Armor arm){
 			armor = arm;
 		}
 
-		public int maxShield() {
+		public synchronized int maxShield() {
 			return 1 + armor.tier + armor.level();
 		}
 	}

core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/sprites/CharSprite.java

@@ -300,7 +300,7 @@ public class CharSprite extends MovieClip implements Tweener.Listener, MovieClip
 		flashTime = FLASH_INTERVAL;
 	}
 	
-	public void add( State state ) {
+	public synchronized void add( State state ) {
 		switch (state) {
 			case BURNING:
 				burning = emitter();
@@ -350,7 +350,7 @@ public class CharSprite extends MovieClip implements Tweener.Listener, MovieClip
 		}
 	}
 	
-	public void remove( State state ) {
+	public synchronized void remove( State state ) {
 		switch (state) {
 			case BURNING:
 				if (burning != null) {
@@ -414,7 +414,6 @@ public class CharSprite extends MovieClip implements Tweener.Listener, MovieClip
 	}
 	
 	@Override
-	//syncronized due to EmoIcon handling
 	public synchronized void update() {
 		
 		super.update();