update music artist when saving artist

MediaBrowser.Controller/Entities/Audio/Artist.cs

@@ -1,7 +1,11 @@
-using System.Runtime.Serialization;
+using System.Globalization;
+using System.Linq;
+using MediaBrowser.Controller.Library;
 using MediaBrowser.Model.Dto;
 using System;
 using System.Collections.Generic;
+using System.Runtime.Serialization;
+using MediaBrowser.Model.Entities;
 
 namespace MediaBrowser.Controller.Entities.Audio
 {
@@ -28,5 +32,37 @@ namespace MediaBrowser.Controller.Entities.Audio
 
         [IgnoreDataMember]
         public Dictionary<Guid, ItemByNameCounts> UserItemCounts { get; set; }
+
+        /// <summary>
+        /// Finds the music artist.
+        /// </summary>
+        /// <param name="artist">The artist.</param>
+        /// <param name="libraryManager">The library manager.</param>
+        /// <returns>MusicArtist.</returns>
+        public static MusicArtist FindMusicArtist(Artist artist, ILibraryManager libraryManager)
+        {
+            return FindMusicArtist(artist, libraryManager.RootFolder.RecursiveChildren.OfType<MusicArtist>());
+        }
+
+        /// <summary>
+        /// Finds the music artist.
+        /// </summary>
+        /// <param name="artist">The artist.</param>
+        /// <param name="allMusicArtists">All music artists.</param>
+        /// <returns>MusicArtist.</returns>
+        public static MusicArtist FindMusicArtist(Artist artist, IEnumerable<MusicArtist> allMusicArtists)
+        {
+            var musicBrainzId = artist.GetProviderId(MetadataProviders.Musicbrainz);
+
+            return allMusicArtists.FirstOrDefault(i =>
+            {
+                if (!string.IsNullOrWhiteSpace(musicBrainzId) && string.Equals(musicBrainzId, i.GetProviderId(MetadataProviders.Musicbrainz), StringComparison.OrdinalIgnoreCase))
+                {
+                    return true;
+                }
+
+                return string.Compare(i.Name, artist.Name, CultureInfo.CurrentCulture, CompareOptions.IgnoreNonSpace | CompareOptions.IgnoreCase | CompareOptions.IgnoreSymbols) == 0;
+            });
+        }
     }
 }