Program: 11106
Project: 11106
Buggy source:
@Override public Object visitQuery(@NotNull cqlParser.QueryContext ctx){
  QueryContext queryContext=new QueryContext();
  List<AliasedQuerySource> sources=(List<AliasedQuerySource>)visit(ctx.sourceClause());
  queryContext.addQuerySources(sources);
  queries.push(queryContext);
  try {
    List<DefineClause> dfcx=ctx.defineClause() != null ? (List<DefineClause>)visit(ctx.defineClause()) : null;
    if (dfcx != null) {
      queryContext.addDefineClauses(dfcx);
    }
    List<RelationshipClause> qicx=new ArrayList<>();
    if (ctx.queryInclusionClause() != null) {
      for (      cqlParser.QueryInclusionClauseContext queryInclusionClauseContext : ctx.queryInclusionClause()) {
        qicx.add((RelationshipClause)visit(queryInclusionClauseContext));
      }
    }
    Expression where=ctx.whereClause() != null ? (Expression)visit(ctx.whereClause()) : null;
    if (dateRangeOptimization && where != null) {
      for (      AliasedQuerySource aqs : sources) {
        where=optimizeDateRangeInQuery(where,aqs);
      }
    }
    ReturnClause ret=ctx.returnClause() != null ? (ReturnClause)visit(ctx.returnClause()) : null;
    if ((ret == null) && (sources.size() > 1)) {
      ret=of.createReturnClause().withDistinct(true);
      Tuple returnExpression=of.createTuple();
      TupleType returnType=new TupleType();
      Boolean anyLists=false;
      for (      AliasedQuerySource aqs : sources) {
        TupleElement element=of.createTupleElement().withName(aqs.getAlias()).withValue(of.createAliasRef().withName(aqs.getAlias()));
        element.setResultType(element.getValue().getResultType());
        returnType.addElement(new TupleTypeElement(element.getName(),element.getResultType()));
        returnExpression.getElement().add(element);
        if (aqs.getResultType() instanceof ListType) {
          anyLists=true;
        }
      }
      returnExpression.setResultType(anyLists ? new ListType(returnType) : returnType);
      ret.setExpression(returnExpression);
      ret.setResultType(returnExpression.getResultType());
    }
    SortClause sort=ctx.sortClause() != null ? (SortClause)visit(ctx.sortClause()) : null;
    Query query=of.createQuery().withSource(sources).withDefine(dfcx).withRelationship(qicx).withWhere(where).withReturn(ret).withSort(sort);
    if (ret == null) {
      query.setResultType(sources.get(0).getResultType());
    }
 else {
      query.setResultType(ret.getResultType());
    }
    return query;
  }
  finally {
    queries.pop();
  }
}

Fixed version (ground truth):
@Override public Object visitQuery(@NotNull cqlParser.QueryContext ctx){
  QueryContext queryContext=new QueryContext();
  List<AliasedQuerySource> sources=(List<AliasedQuerySource>)visit(ctx.sourceClause());
  queryContext.addQuerySources(sources);
  queries.push(queryContext);
  try {
    List<DefineClause> dfcx=ctx.defineClause() != null ? (List<DefineClause>)visit(ctx.defineClause()) : null;
    if (dfcx != null) {
      queryContext.addDefineClauses(dfcx);
    }
    List<RelationshipClause> qicx=new ArrayList<>();
    if (ctx.queryInclusionClause() != null) {
      for (      cqlParser.QueryInclusionClauseContext queryInclusionClauseContext : ctx.queryInclusionClause()) {
        qicx.add((RelationshipClause)visit(queryInclusionClauseContext));
      }
    }
    Expression where=ctx.whereClause() != null ? (Expression)visit(ctx.whereClause()) : null;
    if (dateRangeOptimization && where != null) {
      for (      AliasedQuerySource aqs : sources) {
        where=optimizeDateRangeInQuery(where,aqs);
      }
    }
    ReturnClause ret=ctx.returnClause() != null ? (ReturnClause)visit(ctx.returnClause()) : null;
    if ((ret == null) && (sources.size() > 1)) {
      ret=of.createReturnClause().withDistinct(true);
      Tuple returnExpression=of.createTuple();
      TupleType returnType=new TupleType();
      for (      AliasedQuerySource aqs : sources) {
        TupleElement element=of.createTupleElement().withName(aqs.getAlias()).withValue(of.createAliasRef().withName(aqs.getAlias()));
        element.setResultType(element.getValue().getResultType());
        returnType.addElement(new TupleTypeElement(element.getName(),element.getResultType()));
        returnExpression.getElement().add(element);
      }
      returnExpression.setResultType(queryContext.isSingular() ? returnType : new ListType(returnType));
      ret.setExpression(returnExpression);
      ret.setResultType(returnExpression.getResultType());
    }
    SortClause sort=ctx.sortClause() != null ? (SortClause)visit(ctx.sortClause()) : null;
    Query query=of.createQuery().withSource(sources).withDefine(dfcx).withRelationship(qicx).withWhere(where).withReturn(ret).withSort(sort);
    if (ret == null) {
      query.setResultType(sources.get(0).getResultType());
    }
 else {
      query.setResultType(ret.getResultType());
    }
    return query;
  }
  finally {
    queries.pop();
  }
}