fix: address code review findings

- Fix Torznab default definition protocol (Usenet -> Torrent)
- Add try-catch around JSON deserialization in MAM parser
- Add logging for author info parse failures
- Add null check for JSON response

src/NzbDrone.Core/Indexers/MyAnonamouse/MyAnonamouse.cs

@@ -29,7 +29,7 @@ public override IIndexerRequestGenerator GetRequestGenerator()
 
         public override IParseIndexerResponse GetParser()
         {
-            return new MyAnonamouseParser(Settings);
+            return new MyAnonamouseParser(Settings, _logger);
         }
     }
 }

src/NzbDrone.Core/Indexers/MyAnonamouse/MyAnonamouseParser.cs

@@ -4,6 +4,7 @@
 using System.Linq;
 using System.Net;
 using Newtonsoft.Json;
+using NLog;
 using NzbDrone.Common.Extensions;
 using NzbDrone.Common.Http;
 using NzbDrone.Core.Indexers.Exceptions;
@@ -14,10 +15,12 @@ namespace NzbDrone.Core.Indexers.MyAnonamouse
     public class MyAnonamouseParser : IParseIndexerResponse
     {
         private readonly MyAnonamouseSettings _settings;
+        private readonly Logger _logger;
 
-        public MyAnonamouseParser(MyAnonamouseSettings settings)
+        public MyAnonamouseParser(MyAnonamouseSettings settings, Logger logger = null)
         {
             _settings = settings;
+            _logger = logger ?? LogManager.GetCurrentClassLogger();
         }
 
         public IList<ReleaseInfo> ParseResponse(IndexerResponse indexerResponse)
@@ -36,7 +39,21 @@ public IList<ReleaseInfo> ParseResponse(IndexerResponse indexerResponse)
                     indexerResponse.HttpResponse.StatusCode);
             }
 
-            var jsonResponse = JsonConvert.DeserializeObject<MyAnonamouseResponse>(indexerResponse.Content);
+            MyAnonamouseResponse jsonResponse;
+
+            try
+            {
+                jsonResponse = JsonConvert.DeserializeObject<MyAnonamouseResponse>(indexerResponse.Content);
+            }
+            catch (JsonException ex)
+            {
+                throw new IndexerException(indexerResponse, "Failed to parse JSON response from MyAnonamouse: {0}", ex.Message);
+            }
+
+            if (jsonResponse == null)
+            {
+                throw new IndexerException(indexerResponse, "Empty response from MyAnonamouse");
+            }
 
             if (jsonResponse.Error.IsNotNullOrWhiteSpace() && jsonResponse.Error.StartsWithIgnoreCase("Nothing returned, out of"))
             {
@@ -67,8 +84,9 @@ public IList<ReleaseInfo> ParseResponse(IndexerResponse indexerResponse)
                             title += " by " + author;
                         }
                     }
-                    catch
+                    catch (JsonException ex)
                     {
+                        _logger.Debug(ex, "Failed to parse author info for torrent {0}", id);
                     }
                 }
 

src/NzbDrone.Core/Indexers/Torznab/Torznab.cs

@@ -63,7 +63,7 @@ private IndexerDefinition GetDefinition(string name, TorznabSettings settings)
                 Name = name,
                 Implementation = GetType().Name,
                 Settings = settings,
-                Protocol = DownloadProtocol.Usenet,
+                Protocol = DownloadProtocol.Torrent,
                 SupportsRss = SupportsRss,
                 SupportsSearch = SupportsSearch
             };