Lucene string compare bug

gistfile1.cs

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Globalization;
using System.Threading;
using Lucene.Net.Analysis;
using Lucene.Net.Documents;
using Lucene.Net.Index;
using Lucene.Net.QueryParsers;
using Lucene.Net.Search;
using Lucene.Net.Store;
using Version = Lucene.Net.Util.Version;
using System.Linq;

namespace SimpleLuceneTest
{
    class Program
    {
        static void Main(string[] args)
        {
            var dir = new RAMDirectory();            
            var analyzer = new KeywordAnalyzer();            

            var writer = new IndexWriter(dir, analyzer, true, IndexWriter.MaxFieldLength.UNLIMITED);

            var fields = new[]
                             {
                                "daab", "bcda", "dacb", "dacb",
                                "aacb", "aaac", "bcbb", "acba",
                                "aaaa", "dada" 
                             };
            foreach (var field in fields)
            {
                var doc = new Document();
                doc.Add(new Field("Name", field, Field.Store.NO, Field.Index.ANALYZED_NO_NORMS));
                writer.AddDocument(doc);
            }
            writer.Close(true);

            IndexSearcher searcher = new IndexSearcher(dir, true);
            var termEnum = searcher.GetIndexReader().Terms();
            Console.WriteLine("Indexed Terms:");
            while (termEnum.Next())
            {
                var term = termEnum.Term();
                var freq = termEnum.DocFreq();
                Console.WriteLine("\t {0}:{1,-20} (Count = {2})", term.Field(), term.Text(), freq);
            }
            Console.WriteLine();

            QueryParser queryParser = new QueryParser(Version.LUCENE_29, "", analyzer);

            var queries = new List<string> { "Name:da*" };

            RunQueries(queries, queryParser, searcher);

            Console.WriteLine("-------------------------");
            Console.WriteLine("Changing locale to \"da\"");
            Console.WriteLine("-------------------------\n");
            var culture = CultureInfo.CreateSpecificCulture("da");
            Thread.CurrentThread.CurrentCulture = culture;
            Thread.CurrentThread.CurrentUICulture = culture;

            RunQueries(queries, queryParser, searcher);            
        }

        private static void RunQueries(IEnumerable<string> queries, QueryParser queryParser, IndexSearcher searcher)
        {
            foreach (var queryText in queries)
            {
                var query = queryParser.Parse(queryText);
                Console.WriteLine("Query Used \'{0}\'", query);

                if (query is PrefixQuery)
                {
                    var prefixQuery = query as PrefixQuery;                    
                    var termEnum = prefixQuery.GetEnum(searcher.GetIndexReader());
                    do
                    {
                        Console.WriteLine("\t <" + termEnum.Term() + "> freq=" + termEnum.DocFreq());                        
                    } while (termEnum.Next());                    
                }

                var timer = Stopwatch.StartNew();
                var result = searcher.Search(query, 10);
                timer.Stop();                  

                Console.WriteLine("Query took {0:0.00} ms, there were {1} total hits",
                                  timer.ElapsedMilliseconds, result.totalHits);
                Console.WriteLine(String.Join(", ", result.scoreDocs.Select(x => new { DocId = x.doc })));
                Console.WriteLine();
            }
        }
    }
}