Program: 51401
Project: 51401
Buggy source:
/** 
 * Returns a resized inventory. Returns null if nothing had to be resized.
 * @param player Player currently opening the inventory.
 * @param inventory Inventory. BetterEnderInventoryHolder must be the holder.
 * @param chestOwner
 * @param plugin
 * @return
 */
private static Inventory getResizedEmptyInventory(Player player,Inventory inventory,BetterEnderChest plugin){
  BetterEnderInventoryHolder inventoryHolder=BetterEnderInventoryHolder.of(inventory);
  ChestOwner chestOwner=inventoryHolder.getChestOwner();
  WorldGroup worldGroup=inventoryHolder.getWorldGroup();
  int rows=inventory.getSize() / 9;
  int disabledSlots=inventoryHolder.getDisabledSlots();
  BetterEnderChestSizes chestSizes=plugin.getChestSizes();
  EmptyInventoryProvider emptyChests=plugin.getEmptyInventoryProvider();
  if (chestOwner.isPublicChest()) {
    if (rows != chestSizes.getPublicChestRows() || disabledSlots != chestSizes.getPublicChestDisabledSlots()) {
      return emptyChests.loadEmptyInventory(chestOwner,worldGroup,chestSizes.getPublicChestRows(),chestSizes.getPublicChestDisabledSlots());
    }
  }
 else   if (chestOwner.isDefaultChest()) {
    if (rows != chestSizes.getChestRows() || disabledSlots != chestSizes.getDisabledSlots()) {
      return emptyChests.loadEmptyInventory(chestOwner,worldGroup,chestSizes.getChestRows(),chestSizes.getDisabledSlots());
    }
  }
 else {
    if (chestOwner.isPlayer(player)) {
      if (rows != chestSizes.getChestRows(player) || disabledSlots != chestSizes.getDisabledSlots(player)) {
        return emptyChests.loadEmptyInventory(chestOwner,worldGroup,chestSizes.getChestRows(player),chestSizes.getDisabledSlots(player));
      }
    }
  }
  return null;
}

Fixed version (ground truth):
/** 
 * Returns a resized inventory. Returns null if nothing had to be resized.
 * @param player Player currently opening the inventory.
 * @param inventory Inventory. BetterEnderInventoryHolder must be the holder.
 * @param plugin The plugin instance.
 * @return The resized inventory.
 */
private static Inventory getResizedEmptyInventory(Player player,Inventory inventory,BetterEnderChest plugin){
  BetterEnderInventoryHolder inventoryHolder=BetterEnderInventoryHolder.of(inventory);
  ChestOwner chestOwner=inventoryHolder.getChestOwner();
  WorldGroup worldGroup=inventoryHolder.getWorldGroup();
  int rows=inventory.getSize() / 9;
  int disabledSlots=inventoryHolder.getDisabledSlots();
  BetterEnderChestSizes chestSizes=plugin.getChestSizes();
  EmptyInventoryProvider emptyChests=plugin.getEmptyInventoryProvider();
  if (chestOwner.isPublicChest()) {
    if (rows != chestSizes.getPublicChestRows() || disabledSlots != chestSizes.getPublicChestDisabledSlots()) {
      return emptyChests.loadEmptyInventory(chestOwner,worldGroup,chestSizes.getPublicChestRows(),chestSizes.getPublicChestDisabledSlots());
    }
  }
 else   if (chestOwner.isDefaultChest()) {
    if (rows != chestSizes.getChestRows() || disabledSlots != chestSizes.getDisabledSlots()) {
      return emptyChests.loadEmptyInventory(chestOwner,worldGroup,chestSizes.getChestRows(),chestSizes.getDisabledSlots());
    }
  }
 else {
    if (chestOwner.isPlayer(player)) {
      if (rows != chestSizes.getChestRows(player) || disabledSlots != chestSizes.getDisabledSlots(player)) {
        return emptyChests.loadEmptyInventory(chestOwner,worldGroup,chestSizes.getChestRows(player),chestSizes.getDisabledSlots(player));
      }
    }
  }
  return null;
}