Add support for parsing announce-list as list of strings

Fixes #39

Author: Krusen

BencodeNET.Tests/Torrents/TorrentParserTests.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Text;
 using BencodeNET.IO;
@@ -317,6 +317,31 @@ public void AnnounceList_Multiple_IsParsed(IList<string> announceList1, IList<st
             torrent.Trackers[1].Should().BeEquivalentTo(announceList2);
         }
 
+        [Theory]
+        [AutoMockedData]
+        public void AnnounceList_Multiple_StringsInsteadOfLists_IsParsed(string announce1, string announce2, string announce3)
+        {
+            // Arrange
+            ParsedData = ValidSingleFileTorrentData;
+            ParsedData[TorrentFields.AnnounceList] = new BList
+            {
+                new BString(announce1),
+                new BString(announce2),
+                new BString(announce3),
+            };
+
+            // Act
+            var parser = new TorrentParser(BencodeParser);
+            var torrent = parser.Parse((BencodeReader)null);
+
+            // Assert
+            torrent.Trackers.Should().HaveCount(1);
+            torrent.Trackers[0].Should().HaveCount(3);
+            torrent.Trackers[0][0].Should().Be(announce1);
+            torrent.Trackers[0][1].Should().Be(announce2);
+            torrent.Trackers[0][2].Should().Be(announce3);
+        }
+
         [Theory]
         [AutoMockedData]
         public void AnnounceAndAnnounceList_IsParsed(string announceUrl, IList<string> announceList1, IList<string> announceList2)

BencodeNET/Torrents/TorrentParser.cs

@@ -347,6 +347,8 @@ private void FixEncodingInDictionary(BDictionary data, Encoding encoding)
         /// <returns>A list of list of trackers (announce URLs).</returns>
         protected virtual IList<IList<string>> ParseTrackers(BDictionary data, Encoding encoding)
         {
+            // Specification: http://bittorrent.org/beps/bep_0012.html
+
             var trackerList = new List<IList<string>>();
             var primary = new List<string>();
             trackerList.Add(primary);
@@ -358,18 +360,31 @@ protected virtual IList<IList<string>> ParseTrackers(BDictionary data, Encoding
                 primary.Add(announce);
             }
 
-            // Get the 'announce-list' list´s
-            var announceLists = data.Get<BList>(TorrentFields.AnnounceList)?.AsType<BList>() as IList<BList>;
-            if (announceLists?.Any() == true)
+            // Get the 'announce-list' list's
+            var announceLists = data.Get<BList>(TorrentFields.AnnounceList);
+            if (announceLists == null)
+                return trackerList;
+
+            // According to the specification it should be a list of lists
+            if (announceLists.All(x => x is BList))
             {
-                // Add the first list to the primary list and remove duplicates
-                primary.AddRange(announceLists.First().AsStrings(encoding));
-                trackerList[0] = primary.Distinct().ToList();
+                var lists = announceLists.AsType<BList>() as IList<BList>;
+                if (lists.Any())
+                {
+                    // Add the first list to the primary list and remove duplicates
+                    primary.AddRange(lists.First().AsStrings(encoding));
+                    trackerList[0] = primary.Distinct().ToList();
 
-                // Add the other lists to the lists of lists of announce urls
-                trackerList.AddRange(
-                    announceLists.Skip(1)
-                        .Select(x => x.AsStrings(encoding).ToList()));
+                    // Add the other lists to the lists of lists of announce urls
+                    trackerList.AddRange(lists.Skip(1).Select(x => x.AsStrings(encoding).ToList()));
+                }
+            }
+            // It's not following the specification, it's strings instead of lists
+            else if (ParseMode == TorrentParserMode.Tolerant && announceLists.All(x => x is BString))
+            {
+                // Add them all to the first list
+                primary.AddRange(announceLists.AsStrings(encoding));
+                trackerList[0] = primary.Distinct().ToList();
             }
 
             return trackerList;