Program: 33813
Project: 33813
Buggy source:
@SuppressWarnings("String_Node_Str") @Override public void run(){
  Iterator<Pair<Integer,Integer>> it=chunksToClear.iterator();
  int count=0;
  while (it.hasNext() && count++ < Settings.cleanRate) {
    Pair<Integer,Integer> pair=it.next();
    for (int x=0; x < 16; x++) {
      for (int z=0; z < 16; z++) {
        int xCoord=pair.x * 16 + x;
        int zCoord=pair.z * 16 + z;
        if (island.inIslandSpace(xCoord,zCoord)) {
          for (int y=0; y < ASkyBlock.getIslandWorld().getMaxHeight(); y++) {
            Block b=ASkyBlock.getIslandWorld().getBlockAt(xCoord,y,zCoord);
            Material bt=b.getType();
            Material setTo=Material.AIR;
            if (y < Settings.seaHeight) {
              setTo=Material.STATIONARY_WATER;
            }
switch (bt) {
case CHEST:
case TRAPPED_CHEST:
case FURNACE:
case DISPENSER:
case HOPPER:
              final InventoryHolder ih=((InventoryHolder)b.getState());
            ih.getInventory().clear();
          b.setType(setTo);
        break;
case AIR:
      if (setTo.equals(Material.STATIONARY_WATER)) {
        nms.setBlockSuperFast(b,setTo.getId(),(byte)0,false);
      }
case STATIONARY_WATER:
    if (setTo.equals(Material.AIR)) {
      nms.setBlockSuperFast(b,setTo.getId(),(byte)0,false);
    }
default :
  nms.setBlockSuperFast(b,setTo.getId(),(byte)0,false);
break;
}
if (Settings.newNether && Settings.createNether && y < ASkyBlock.getNetherWorld().getMaxHeight() - 8) {
b=ASkyBlock.getNetherWorld().getBlockAt(xCoord,y,zCoord);
bt=b.getType();
if (!b.equals(Material.AIR)) {
setTo=Material.AIR;
switch (bt) {
case CHEST:
case TRAPPED_CHEST:
case FURNACE:
case DISPENSER:
case HOPPER:
  final InventoryHolder ih=((InventoryHolder)b.getState());
ih.getInventory().clear();
b.setType(setTo);
break;
default :
nms.setBlockSuperFast(b,setTo.getId(),(byte)0,false);
break;
}
}
}
}
}
}
}
it.remove();
}
if (chunksToClear.isEmpty()) {
plugin.getLogger().info("String_Node_Str");
this.cancel();
}
}

Fixed version (ground truth):
@SuppressWarnings("String_Node_Str") @Override public void run(){
  Iterator<Pair<Integer,Integer>> it=chunksToClear.iterator();
  int count=0;
  while (it.hasNext() && count++ < Settings.cleanRate) {
    Pair<Integer,Integer> pair=it.next();
    for (int x=0; x < 16; x++) {
      for (int z=0; z < 16; z++) {
        int xCoord=pair.x * 16 + x;
        int zCoord=pair.z * 16 + z;
        if (island.inIslandSpace(xCoord,zCoord)) {
          for (int y=0; y < ASkyBlock.getIslandWorld().getMaxHeight(); y++) {
            Block block=ASkyBlock.getIslandWorld().getBlockAt(xCoord,y,zCoord);
            Material blockType=block.getType();
            Material setTo=Material.AIR;
            if (y < Settings.seaHeight) {
              setTo=Material.STATIONARY_WATER;
            }
switch (blockType) {
case CHEST:
case TRAPPED_CHEST:
case FURNACE:
case DISPENSER:
case HOPPER:
              final InventoryHolder ih=((InventoryHolder)block.getState());
            ih.getInventory().clear();
          block.setType(setTo);
        break;
case AIR:
      if (setTo.equals(Material.STATIONARY_WATER)) {
        nms.setBlockSuperFast(block,setTo.getId(),(byte)0,false);
      }
case STATIONARY_WATER:
    if (setTo.equals(Material.AIR)) {
      nms.setBlockSuperFast(block,setTo.getId(),(byte)0,false);
    }
default :
  nms.setBlockSuperFast(block,setTo.getId(),(byte)0,false);
break;
}
if (Settings.newNether && Settings.createNether && y < ASkyBlock.getNetherWorld().getMaxHeight() - 8) {
block=ASkyBlock.getNetherWorld().getBlockAt(xCoord,y,zCoord);
blockType=block.getType();
if (!blockType.equals(Material.AIR)) {
setTo=Material.AIR;
switch (blockType) {
case CHEST:
case TRAPPED_CHEST:
case FURNACE:
case DISPENSER:
case HOPPER:
  final InventoryHolder ih=((InventoryHolder)block.getState());
ih.getInventory().clear();
block.setType(setTo);
break;
default :
nms.setBlockSuperFast(block,setTo.getId(),(byte)0,false);
break;
}
}
}
}
}
}
}
it.remove();
}
if (chunksToClear.isEmpty()) {
plugin.getLogger().info("String_Node_Str");
this.cancel();
}
}