Program: 39030
Project: 39030
Buggy source:
private void createNewChanges(){
  final List<RevCommit> toCreate=new ArrayList<RevCommit>();
  final RevWalk walk=rp.getRevWalk();
  walk.reset();
  walk.sort(RevSort.TOPO);
  walk.sort(RevSort.REVERSE,true);
  try {
    walk.markStart(walk.parseCommit(newChange.getNewId()));
    for (    ObjectId id : existingObjects()) {
      try {
        walk.markUninteresting(walk.parseCommit(id));
      }
 catch (      IOException e) {
        continue;
      }
    }
    for (; ; ) {
      final RevCommit c=walk.next();
      if (c == null) {
        break;
      }
      if (replaceByCommit.containsKey(c)) {
        continue;
      }
      if (!validCommit(destBranchCtl,newChange,c)) {
        return;
      }
      final List<String> idList=c.getFooterLines(CHANGE_ID);
      if (!idList.isEmpty()) {
        final String idStr=idList.get(idList.size() - 1).trim();
        final Change.Key key=new Change.Key(idStr);
        final List<Change> changes=db.changes().byProjectKey(project.getNameKey(),key).toList();
        if (changes.size() > 1) {
          reject(newChange,key.get() + "String_Node_Str");
          return;
        }
        if (changes.size() == 1) {
          requestReplace(newChange,changes.get(0),c);
          continue;
        }
      }
      toCreate.add(c);
    }
  }
 catch (  IOException e) {
    newChange.setResult(Result.REJECTED_MISSING_OBJECT);
    log.error("String_Node_Str",e);
    return;
  }
catch (  OrmException e) {
    log.error("String_Node_Str",e);
    reject(newChange,"String_Node_Str");
    return;
  }
  if (toCreate.isEmpty() && replaceByChange.isEmpty()) {
    reject(newChange,"String_Node_Str");
    return;
  }
  for (  final RevCommit c : toCreate) {
    try {
      createChange(walk,c);
    }
 catch (    IOException e) {
      log.error("String_Node_Str" + c.name(),e);
      reject(newChange,"String_Node_Str");
      return;
    }
catch (    OrmException e) {
      log.error("String_Node_Str" + c.name(),e);
      reject(newChange,"String_Node_Str");
      return;
    }
  }
  newChange.setResult(ReceiveCommand.Result.OK);
}

Fixed version (ground truth):
private void createNewChanges(){
  final List<RevCommit> toCreate=new ArrayList<RevCommit>();
  final RevWalk walk=rp.getRevWalk();
  walk.reset();
  walk.sort(RevSort.TOPO);
  walk.sort(RevSort.REVERSE,true);
  try {
    walk.markStart(walk.parseCommit(newChange.getNewId()));
    for (    ObjectId id : existingObjects()) {
      try {
        walk.markUninteresting(walk.parseCommit(id));
      }
 catch (      IOException e) {
        continue;
      }
    }
    for (; ; ) {
      final RevCommit c=walk.next();
      if (c == null) {
        break;
      }
      if (replaceByCommit.containsKey(c)) {
        continue;
      }
      if (!validCommit(destBranchCtl,newChange,c)) {
        return;
      }
      final List<String> idList=c.getFooterLines(CHANGE_ID);
      if (!idList.isEmpty()) {
        final String idStr=idList.get(idList.size() - 1).trim();
        final Change.Key key=new Change.Key(idStr);
        final List<Change> changes=db.changes().byProjectKey(project.getNameKey(),key).toList();
        if (changes.size() > 1) {
          reject(newChange,key.get() + "String_Node_Str");
          return;
        }
        if (changes.size() == 1) {
          if (requestReplace(newChange,changes.get(0),c)) {
            continue;
          }
 else {
            return;
          }
        }
      }
      toCreate.add(c);
    }
  }
 catch (  IOException e) {
    newChange.setResult(Result.REJECTED_MISSING_OBJECT);
    log.error("String_Node_Str",e);
    return;
  }
catch (  OrmException e) {
    log.error("String_Node_Str",e);
    reject(newChange,"String_Node_Str");
    return;
  }
  if (toCreate.isEmpty() && replaceByChange.isEmpty()) {
    reject(newChange,"String_Node_Str");
    return;
  }
  for (  final RevCommit c : toCreate) {
    try {
      createChange(walk,c);
    }
 catch (    IOException e) {
      log.error("String_Node_Str" + c.name(),e);
      reject(newChange,"String_Node_Str");
      return;
    }
catch (    OrmException e) {
      log.error("String_Node_Str" + c.name(),e);
      reject(newChange,"String_Node_Str");
      return;
    }
  }
  newChange.setResult(ReceiveCommand.Result.OK);
}