Program: 17988
Project: 17988
Buggy source:
@Override protected QueryNode preProcessNode(QueryNode node) throws QueryNodeException {
  if (node instanceof AqpAnalyzedQueryNode) {
    QueryNode child=((AqpAnalyzedQueryNode)node).getChild();
    List<List<List<QueryNode>>> queryStructure;
    AqpRequestParams req=getRequest();
    SolrParams params=req.getParams();
    final String unfieldedDefaultOperator="String_Node_Str";
    if (params != null) {
      params.get(AqpAdsabsQueryParser.AQP_UNFIELDED_OPERATOR_PARAM,"String_Node_Str").toLowerCase();
    }
    if (child instanceof TokenizedPhraseQueryNode) {
      return child;
    }
 else     if (child instanceof GroupQueryNode) {
      if (child.getChildren().size() > 0 && child.getChildren().get(0) instanceof BooleanQueryNode && ((BooleanQueryNode)child.getChildren().get(0)).getChildren().size() > 1) {
        queryStructure=extractQueries(child.getChildren().get(0));
        final int proximity=getDefaultProximityValue();
        return buildNewQueryNode(queryStructure,new QueryBuilder(){
          @Override public QueryNode buildQuery(          List<QueryNode> clauses){
            if (unfieldedDefaultOperator.equals("String_Node_Str")) {
              return new AqpNearQueryNode(clauses,proximity);
            }
 else             if (unfieldedDefaultOperator.equals("String_Node_Str")) {
              return new AqpAndQueryNode(clauses);
            }
 else             if (unfieldedDefaultOperator.equals("String_Node_Str")) {
              return new AqpNotQueryNode(clauses);
            }
 else {
              return new AqpOrQueryNode(clauses);
            }
          }
        }
);
      }
    }
 else     if (child instanceof MultiPhraseQueryNode) {
      queryStructure=extractQueries(child);
      if (node.getParent() instanceof FuzzyQueryNode) {
        final FuzzyQueryNode parent=(FuzzyQueryNode)node.getParent();
        return buildNewQueryNode(queryStructure,new QueryBuilder(){
          @Override public QueryNode buildQuery(          List<QueryNode> clauses){
            return new AqpNearQueryNode(clauses,parent.getPositionIncrement());
          }
        }
);
      }
 else {
        return buildNewQueryNode(queryStructure,new QueryBuilder(){
          @Override public QueryNode buildQuery(          List<QueryNode> clauses){
            if (this.isMultiDimensional) {
              MultiPhraseQueryNode pq=new MultiPhraseQueryNode();
              for (              QueryNode c : clauses) {
                if (c.isLeaf()) {
                  pq.add(c);
                }
 else {
                  for (                  QueryNode child : c.getChildren()) {
                    pq.add(child);
                  }
                }
              }
              return pq;
            }
 else {
              TokenizedPhraseQueryNode pq=new TokenizedPhraseQueryNode();
              pq.add(clauses);
              return pq;
            }
          }
        }
);
      }
    }
    return child;
  }
  return node;
}

Fixed version (ground truth):
@Override protected QueryNode preProcessNode(QueryNode node) throws QueryNodeException {
  if (node.getTag(AqpAdsabsAnalyzerProcessor.ANALYZED) != null) {
    List<List<List<QueryNode>>> queryStructure;
    AqpRequestParams req=getRequest();
    SolrParams params=req.getParams();
    final String unfieldedDefaultOperator="String_Node_Str";
    if (params != null) {
      params.get(AqpAdsabsQueryParser.AQP_UNFIELDED_OPERATOR_PARAM,"String_Node_Str").toLowerCase();
    }
    if (node instanceof TokenizedPhraseQueryNode) {
      return node;
    }
 else     if (node instanceof GroupQueryNode) {
      if (node.getChildren().size() > 0 && node.getChildren().get(0) instanceof BooleanQueryNode && ((BooleanQueryNode)node.getChildren().get(0)).getChildren().size() > 1) {
        queryStructure=extractQueries(node.getChildren().get(0));
        final int proximity=getDefaultProximityValue();
        return buildNewQueryNode(queryStructure,new QueryBuilder(){
          @Override public QueryNode buildQuery(          List<QueryNode> clauses){
            if (unfieldedDefaultOperator.equals("String_Node_Str")) {
              return new AqpNearQueryNode(clauses,proximity);
            }
 else             if (unfieldedDefaultOperator.equals("String_Node_Str")) {
              return new AqpAndQueryNode(clauses);
            }
 else             if (unfieldedDefaultOperator.equals("String_Node_Str")) {
              return new AqpNotQueryNode(clauses);
            }
 else {
              return new AqpOrQueryNode(clauses);
            }
          }
        }
);
      }
    }
 else     if (node instanceof MultiPhraseQueryNode) {
      queryStructure=extractQueries(node);
      if (node.getParent() instanceof FuzzyQueryNode) {
        final FuzzyQueryNode parent=(FuzzyQueryNode)node.getParent();
        return buildNewQueryNode(queryStructure,new QueryBuilder(){
          @Override public QueryNode buildQuery(          List<QueryNode> clauses){
            return new AqpNearQueryNode(clauses,parent.getPositionIncrement());
          }
        }
);
      }
 else {
        return buildNewQueryNode(queryStructure,new QueryBuilder(){
          @Override public QueryNode buildQuery(          List<QueryNode> clauses){
            if (this.isMultiDimensional) {
              MultiPhraseQueryNode pq=new MultiPhraseQueryNode();
              for (              QueryNode c : clauses) {
                if (c.isLeaf()) {
                  pq.add(c);
                }
 else {
                  for (                  QueryNode child : c.getChildren()) {
                    pq.add(child);
                  }
                }
              }
              return pq;
            }
 else {
              TokenizedPhraseQueryNode pq=new TokenizedPhraseQueryNode();
              pq.add(clauses);
              return pq;
            }
          }
        }
);
      }
    }
    return node;
  }
  return node;
}