Program: 130750
Project: 130750
Buggy source:
public void lead() throws Exception {
  try {
    changePhase(Phase.DISCOVERING);
    waitProposedEpochFromQuorum();
    proposeNewEpoch();
    waitEpochAckFromQuorum();
    LOG.debug("String_Node_Str",persistence.getProposedEpoch());
    String peerId=selectSyncHistoryOwner();
    LOG.debug("String_Node_Str",peerId);
    LOG.debug("String_Node_Str");
    changePhase(Phase.SYNCHRONIZING);
    if (!peerId.equals(this.serverId)) {
      synchronizeFromFollower(peerId);
    }
    persistence.setAckEpoch(persistence.getProposedEpoch());
    long st=System.nanoTime();
    beginSynchronizing();
    waitNewLeaderAckFromQuorum();
    long syncTime=System.nanoTime() - st;
    adjustSyncTimeout((int)(syncTime / 1000000));
    Message commit=MessageBuilder.buildCommit(persistence.getLog().getLatestZxid());
    broadcast(this.quorumSet.keySet().iterator(),commit);
    restoreFromSnapshot();
    deliverUndeliveredTxns();
    changePhase(Phase.BROADCASTING);
    for (    PeerHandler ph : this.quorumSet.values()) {
      ph.startBroadcastingTask();
      ph.updateHeartbeatTime();
    }
    LOG.info("String_Node_Str");
    broadcasting();
  }
 catch (  InterruptedException e) {
    LOG.debug("String_Node_Str");
    throw e;
  }
catch (  TimeoutException e) {
    LOG.debug("String_Node_Str" + "String_Node_Str",this.config.getTimeoutMs());
  }
catch (  BackToElectionException e) {
    LOG.debug("String_Node_Str");
  }
catch (  Zab.SimulatedException e) {
    LOG.debug("String_Node_Str");
  }
catch (  LeftCluster e) {
    LOG.debug("String_Node_Str",e.getMessage());
    throw e;
  }
catch (  Exception e) {
    LOG.error("String_Node_Str",e);
    throw e;
  }
 finally {
    if (this.currentPhase == Phase.SYNCHRONIZING) {
      incSyncTimeout();
      LOG.debug("String_Node_Str" + "String_Node_Str",getSyncTimeoutMs());
    }
    changePhase(Phase.FINALIZING);
  }
}

Fixed version (ground truth):
public void lead() throws Exception {
  try {
    changePhase(Phase.DISCOVERING);
    waitProposedEpochFromQuorum();
    proposeNewEpoch();
    waitEpochAckFromQuorum();
    LOG.debug("String_Node_Str",persistence.getProposedEpoch());
    String peerId=selectSyncHistoryOwner();
    LOG.debug("String_Node_Str",peerId);
    LOG.debug("String_Node_Str");
    changePhase(Phase.SYNCHRONIZING);
    if (!peerId.equals(this.serverId)) {
      synchronizeFromFollower(peerId);
    }
    persistence.setAckEpoch(persistence.getProposedEpoch());
    long st=System.nanoTime();
    beginSynchronizing();
    waitNewLeaderAckFromQuorum();
    long syncTime=System.nanoTime() - st;
    adjustSyncTimeout((int)(syncTime / 1000000));
    Message commit=MessageBuilder.buildCommit(persistence.getLog().getLatestZxid());
    broadcast(this.quorumSet.keySet().iterator(),commit);
    restoreFromSnapshot();
    deliverUndeliveredTxns();
    changePhase(Phase.BROADCASTING);
    for (    PeerHandler ph : this.quorumSet.values()) {
      ph.startBroadcastingTask();
      ph.updateHeartbeatTime();
    }
    broadcasting();
  }
 catch (  InterruptedException e) {
    LOG.debug("String_Node_Str");
    throw e;
  }
catch (  TimeoutException e) {
    LOG.debug("String_Node_Str" + "String_Node_Str",this.config.getTimeoutMs());
  }
catch (  BackToElectionException e) {
    LOG.debug("String_Node_Str");
  }
catch (  Zab.SimulatedException e) {
    LOG.debug("String_Node_Str");
  }
catch (  LeftCluster e) {
    LOG.debug("String_Node_Str",e.getMessage());
    throw e;
  }
catch (  Exception e) {
    LOG.error("String_Node_Str",e);
    throw e;
  }
 finally {
    if (this.currentPhase == Phase.SYNCHRONIZING) {
      incSyncTimeout();
      LOG.debug("String_Node_Str" + "String_Node_Str",getSyncTimeoutMs());
    }
    changePhase(Phase.FINALIZING);
  }
}