Program: 21031
Project: 21031
Buggy source:
public static void main(String[] args){
  byte[] sk=new byte[32];
  Arrays.fill(sk,(byte)0);
  byte[] pk=Ed25519.publickey(sk);
  System.out.println("String_Node_Str" + getHex(pk) + "String_Node_Str");
  System.out.println("String_Node_Str" + getHex(Ed25519.encodeint(BigInteger.ZERO)));
  System.out.println("String_Node_Str" + getHex(Ed25519.encodeint(BigInteger.ONE)));
  System.out.println("String_Node_Str" + getHex(Ed25519.encodeint(BigInteger.TEN)));
  BigInteger[] zerozero=new BigInteger[]{BigInteger.ZERO,BigInteger.ZERO};
  BigInteger[] oneone=new BigInteger[]{BigInteger.ONE,BigInteger.ONE};
  BigInteger[] tenzero=new BigInteger[]{BigInteger.TEN,BigInteger.ZERO};
  BigInteger[] oneten=new BigInteger[]{BigInteger.ONE,BigInteger.TEN};
  BigInteger[] pkr=new BigInteger[]{new BigInteger("String_Node_Str"),new BigInteger("String_Node_Str")};
  System.out.println("String_Node_Str" + getHex(Ed25519.encodepoint(zerozero)));
  System.out.println("String_Node_Str" + getHex(Ed25519.encodepoint(oneone)));
  System.out.println("String_Node_Str" + getHex(Ed25519.encodepoint(tenzero)));
  System.out.println("String_Node_Str" + getHex(Ed25519.encodepoint(oneten)));
  System.out.println("String_Node_Str" + getHex(Ed25519.encodepoint(pkr)));
  byte[] message="String_Node_Str".getBytes(Charset.forName("String_Node_Str"));
  byte[] signature=Ed25519.signature(message,sk,pk);
  System.out.println("String_Node_Str" + getHex(signature));
  try {
    System.out.println("String_Node_Str" + Ed25519.checkvalid(signature,message,pk));
  }
 catch (  Exception e) {
    e.printStackTrace();
  }
}

Fixed version (ground truth):
public static void main(String[] args){
  byte[] sk=new byte[32];
  Arrays.fill(sk,(byte)0);
  byte[] pk=Ed25519.publickey(sk);
  System.out.println("String_Node_Str" + getHex(pk) + "String_Node_Str");
  System.out.println("String_Node_Str" + getHex(FieldElement.ZERO.toByteArray()));
  System.out.println("String_Node_Str" + getHex(FieldElement.ONE.toByteArray()));
  System.out.println("String_Node_Str" + getHex(new FieldElement(BigInteger.TEN).toByteArray()));
  BigInteger[] zerozero=new BigInteger[]{BigInteger.ZERO,BigInteger.ZERO};
  BigInteger[] oneone=new BigInteger[]{BigInteger.ONE,BigInteger.ONE};
  BigInteger[] tenzero=new BigInteger[]{BigInteger.TEN,BigInteger.ZERO};
  BigInteger[] oneten=new BigInteger[]{BigInteger.ONE,BigInteger.TEN};
  BigInteger[] pkr=new BigInteger[]{new BigInteger("String_Node_Str"),new BigInteger("String_Node_Str")};
  System.out.println("String_Node_Str" + getHex(Ed25519.encodepoint(zerozero)));
  System.out.println("String_Node_Str" + getHex(Ed25519.encodepoint(oneone)));
  System.out.println("String_Node_Str" + getHex(Ed25519.encodepoint(tenzero)));
  System.out.println("String_Node_Str" + getHex(Ed25519.encodepoint(oneten)));
  System.out.println("String_Node_Str" + getHex(Ed25519.encodepoint(pkr)));
  byte[] message="String_Node_Str".getBytes(Charset.forName("String_Node_Str"));
  byte[] signature=Ed25519.signature(message,sk,pk);
  System.out.println("String_Node_Str" + getHex(signature));
  try {
    System.out.println("String_Node_Str" + Ed25519.checkvalid(signature,message,pk));
  }
 catch (  Exception e) {
    e.printStackTrace();
  }
}