Program: 85820
Project: 85820
Buggy source:
/** 
 * Given a spend request containing an incomplete transaction, makes it valid by adding inputs and outputs according to the instructions in the request. The transaction in the request is modified by this method.
 * @param req a SendRequest that contains the incomplete transaction and details for how to make it valid.
 * @throws IllegalArgumentException if you try and complete the same SendRequest twice.
 * @return False if we cannot afford this send, true otherwise.
 */
public boolean completeTx(SendRequest req){
  lock.lock();
  try {
    Preconditions.checkArgument(!req.completed,"String_Node_Str");
    BigInteger value=BigInteger.ZERO;
    for (    TransactionOutput output : req.tx.getOutputs()) {
      value=value.add(output.getValue());
    }
    value=value.add(req.fee);
    log.info("String_Node_Str",req.tx.getOutputs().size(),bitcoinValueToFriendlyString(value));
    LinkedList<TransactionOutput> candidates=calculateSpendCandidates(true);
    CoinSelection selection=coinSelector.select(value,candidates);
    if (selection.valueGathered.compareTo(value) < 0) {
      log.warn("String_Node_Str" + bitcoinValueToFriendlyString(value.subtract(selection.valueGathered)));
      return false;
    }
    checkState(selection.gathered.size() > 0);
    req.tx.getConfidence().setConfidenceType(ConfidenceType.NOT_SEEN_IN_CHAIN);
    BigInteger change=selection.valueGathered.subtract(value);
    if (change.compareTo(BigInteger.ZERO) > 0) {
      Address changeAddress=req.changeAddress != null ? req.changeAddress : getChangeAddress();
      log.info("String_Node_Str",bitcoinValueToFriendlyString(change));
      req.tx.addOutput(new TransactionOutput(params,req.tx,change,changeAddress));
    }
    for (    TransactionOutput output : selection.gathered) {
      req.tx.addInput(output);
    }
    try {
      req.tx.signInputs(Transaction.SigHash.ALL,this,req.aesKey);
    }
 catch (    ScriptException e) {
      throw new RuntimeException(e);
    }
    int size=req.tx.bitcoinSerialize().length;
    if (size > Transaction.MAX_STANDARD_TX_SIZE) {
      log.error("String_Node_Str",size,Transaction.MAX_STANDARD_TX_SIZE);
      return false;
    }
    req.tx.getConfidence().setSource(TransactionConfidence.Source.SELF);
    req.completed=true;
    log.info("String_Node_Str",req.tx.getHashAsString());
    return true;
  }
  finally {
    lock.unlock();
  }
}

Fixed version (ground truth):
/** 
 * Given a spend request containing an incomplete transaction, makes it valid by adding inputs and outputs according to the instructions in the request. The transaction in the request is modified by this method.
 * @param req a SendRequest that contains the incomplete transaction and details for how to make it valid.
 * @throws IllegalArgumentException if you try and complete the same SendRequest twice.
 * @return False if we cannot afford this send, true otherwise.
 */
public boolean completeTx(SendRequest req){
  lock.lock();
  try {
    Preconditions.checkArgument(!req.completed,"String_Node_Str");
    BigInteger value=BigInteger.ZERO;
    for (    TransactionOutput output : req.tx.getOutputs()) {
      value=value.add(output.getValue());
    }
    value=value.add(req.fee);
    log.info("String_Node_Str",req.tx.getOutputs().size(),bitcoinValueToFriendlyString(value));
    LinkedList<TransactionOutput> candidates=calculateSpendCandidates(true);
    CoinSelection selection=coinSelector.select(value,candidates);
    if (selection.valueGathered.compareTo(value) < 0) {
      log.warn("String_Node_Str" + bitcoinValueToFriendlyString(value.subtract(selection.valueGathered)));
      return false;
    }
    checkState(selection.gathered.size() > 0);
    req.tx.getConfidence().setConfidenceType(ConfidenceType.NOT_SEEN_IN_CHAIN);
    BigInteger change=selection.valueGathered.subtract(value);
    if (change.compareTo(BigInteger.ZERO) > 0) {
      Address changeAddress=req.changeAddress != null ? req.changeAddress : getChangeAddress();
      log.info("String_Node_Str",bitcoinValueToFriendlyString(change));
      req.tx.addOutput(new TransactionOutput(params,req.tx,change,changeAddress));
    }
    for (    TransactionOutput output : selection.gathered) {
      req.tx.addInput(output);
    }
    try {
      req.tx.signInputs(Transaction.SigHash.ALL,this,req.aesKey);
    }
 catch (    ScriptException e) {
      throw new RuntimeException(e);
    }
    int size=req.tx.bitcoinSerialize().length;
    if (size > Transaction.MAX_STANDARD_TX_SIZE) {
      log.error("String_Node_Str",size,Transaction.MAX_STANDARD_TX_SIZE);
      return false;
    }
    req.tx.getConfidence().setSource(TransactionConfidence.Source.SELF);
    req.completed=true;
    log.info("String_Node_Str",req.tx.getHashAsString(),req.tx.getInputs().size());
    return true;
  }
  finally {
    lock.unlock();
  }
}