fixes #157 - a handful of persistent artist have failure to download BIOs

MediaBrowser.Controller/Providers/Music/LastfmArtistProvider.cs

@@ -93,8 +93,6 @@ namespace MediaBrowser.Controller.Providers.Music
             //Execute the Artist search against our name and assume first one is the one we want
             var url = RootUrl + string.Format("method=artist.search&artist={0}&api_key={1}&format=json", UrlEncode(item.Name), ApiKey);
 
-            LastfmArtistSearchResults searchResult;
-
             try
             {
                 using (var json = await HttpClient.Get(new HttpRequestOptions
@@ -106,14 +104,18 @@ namespace MediaBrowser.Controller.Providers.Music
 
                 }).ConfigureAwait(false))
                 {
-                    searchResult = JsonSerializer.DeserializeFromStream<LastfmArtistSearchResults>(json);
-                }
-            }
-            catch (HttpException e)
+                    using (var reader = new StreamReader(json, true))
+                    {
+                        var jsonString = await reader.ReadToEndAsync().ConfigureAwait(false);
+
+                        // Sometimes they send back an empty response or just the text "null"
+                        if (!jsonString.StartsWith("{", StringComparison.OrdinalIgnoreCase))
                         {
                             return null;
                         }
 
+                        var searchResult = JsonSerializer.DeserializeFromString<LastfmArtistSearchResults>(jsonString);
+
                         if (searchResult != null && searchResult.results != null && searchResult.results.artistmatches != null && searchResult.results.artistmatches.artist.Count > 0)
                         {
                             var artist = searchResult.results.artistmatches.artist.FirstOrDefault(i => i.name != null && string.Compare(i.name, item.Name, CultureInfo.CurrentCulture, CompareOptions.IgnoreNonSpace) == 0) ??
@@ -121,6 +123,13 @@ namespace MediaBrowser.Controller.Providers.Music
 
                             return artist.mbid;
                         }
+                    }
+                }
+            }
+            catch (HttpException)
+            {
+                return null;
+            }
 
             return null;
         }