Program: 141620
Project: 141620
Buggy source:
@Override public void run(final CommandSender cs,String label,String[] args){
  if (!r.isPlayer(cs)) {
    return;
  }
  if (!r.perm(cs,"String_Node_Str",false,true)) {
    return;
  }
  Player p=(Player)cs;
  Boolean spawnin=!(p.getItemInHand().getType() == Material.FIREWORK);
  ItemStack stack=p.getItemInHand().getType() == Material.FIREWORK ? p.getItemInHand() : new ItemStack(Material.FIREWORK);
  if (!r.checkArgs(args,0)) {
    r.sendMes(cs,"String_Node_Str");
    return;
  }
  if (args[0].equalsIgnoreCase("String_Node_Str") && (p.getItemInHand().getType() == Material.FIREWORK)) {
    FireworkMeta fmeta=(FireworkMeta)stack.getItemMeta();
    fmeta.clearEffects();
    stack.setItemMeta(fmeta);
    r.sendMes(cs,"String_Node_Str");
    return;
  }
  MetaItemStack mStack=new MetaItemStack(stack);
  for (  String arg : args) {
    if (arg.equalsIgnoreCase("String_Node_Str") || arg.equalsIgnoreCase("String_Node_Str")) {
      FireworkMeta fmeta=(FireworkMeta)stack.getItemMeta();
      try {
        int power=Integer.parseInt(arg.split("String_Node_Str")[1]);
        try {
          mStack.addFireworkMeta(cs,true,"String_Node_Str" + power);
        }
 catch (        Exception e) {
          r.sendMes(cs,"String_Node_Str");
        }
      }
 catch (      NumberFormatException e) {
        r.sendMes(cs,"String_Node_Str");
        return;
      }
      stack.setItemMeta(fmeta);
    }
 else     if (r.isInt(arg)) {
      stack.setAmount(Integer.parseInt(arg));
    }
 else {
      try {
        mStack.addFireworkMeta(p,true,arg);
      }
 catch (      Exception e) {
        r.sendMes(cs,"String_Node_Str");
        return;
      }
    }
  }
  if (mStack.isValidFirework()) {
    FireworkMeta fmeta=(FireworkMeta)mStack.getItemStack().getItemMeta();
    FireworkEffect effect=mStack.getFireworkBuilder().build();
    fmeta.addEffect(effect);
    stack.setItemMeta(fmeta);
  }
 else {
    r.sendMes(cs,"String_Node_Str");
    return;
  }
  if (spawnin) {
    r.sendMes(cs,"String_Node_Str");
    p.getInventory().addItem(stack);
  }
 else {
    r.sendMes(cs,"String_Node_Str");
  }
}

Fixed version (ground truth):
@Override public void run(final CommandSender cs,String label,String[] args){
  if (!r.isPlayer(cs)) {
    return;
  }
  if (!r.perm(cs,"String_Node_Str",false,true)) {
    return;
  }
  Player p=(Player)cs;
  Boolean spawnin=!(p.getItemInHand().getType() == Material.FIREWORK);
  ItemStack stack=p.getItemInHand().getType() == Material.FIREWORK ? p.getItemInHand() : new ItemStack(Material.FIREWORK);
  if (!r.checkArgs(args,0)) {
    r.sendMes(cs,"String_Node_Str");
    return;
  }
  if (args[0].equalsIgnoreCase("String_Node_Str") && (p.getItemInHand().getType() == Material.FIREWORK)) {
    FireworkMeta fmeta=(FireworkMeta)stack.getItemMeta();
    fmeta.clearEffects();
    stack.setItemMeta(fmeta);
    r.sendMes(cs,"String_Node_Str");
    return;
  }
  MetaItemStack mStack=new MetaItemStack(stack);
  for (  String arg : args) {
    if (arg.equalsIgnoreCase("String_Node_Str") || arg.equalsIgnoreCase("String_Node_Str")) {
      FireworkMeta fmeta=(FireworkMeta)stack.getItemMeta();
      try {
        int power=Integer.parseInt(arg.split("String_Node_Str")[1]);
        try {
          mStack.addFireworkMeta(true,"String_Node_Str" + power);
        }
 catch (        Exception e) {
          r.sendMes(cs,"String_Node_Str");
        }
      }
 catch (      NumberFormatException e) {
        r.sendMes(cs,"String_Node_Str");
        return;
      }
      stack.setItemMeta(fmeta);
    }
 else     if (r.isInt(arg)) {
      stack.setAmount(Integer.parseInt(arg));
    }
 else {
      try {
        mStack.addFireworkMeta(true,arg);
      }
 catch (      Exception e) {
        r.sendMes(cs,"String_Node_Str");
        return;
      }
    }
  }
  if (mStack.isValidFirework()) {
    FireworkMeta fmeta=(FireworkMeta)mStack.getItemStack().getItemMeta();
    FireworkEffect effect=mStack.getFireworkBuilder().build();
    fmeta.addEffect(effect);
    stack.setItemMeta(fmeta);
  }
 else {
    r.sendMes(cs,"String_Node_Str");
    return;
  }
  if (spawnin) {
    r.sendMes(cs,"String_Node_Str");
    p.getInventory().addItem(stack);
  }
 else {
    r.sendMes(cs,"String_Node_Str");
  }
}