New: Use languages from Torznab/Newznab attributes if given

(cherry picked from commit 9c5a07f62a6e32832c10c80813cd3b98c5859989)

src/NzbDrone.Core/Indexers/Definitions/Headphones/HeadphonesRssParser.cs

@@ -126,6 +126,28 @@ namespace NzbDrone.Core.Indexers.Headphones
             return results;
         }
 
+        protected override List<string> GetLanguages(XElement item)
+        {
+            var languges = TryGetMultipleNewznabAttributes(item, "language");
+            var results = new List<string>();
+
+            // Try to find <language> elements for some indexers that suck at following the rules.
+            if (languges.Count == 0)
+            {
+                languges = item.Elements("language").Select(e => e.Value).ToList();
+            }
+
+            foreach (var language in languges)
+            {
+                if (language.IsNotNullOrWhiteSpace())
+                {
+                    results.Add(language);
+                }
+            }
+
+            return results;
+        }
+
         protected override long GetSize(XElement item)
         {
             long size;

src/NzbDrone.Core/Indexers/Definitions/Newznab/NewznabRssParser.cs

@@ -154,6 +154,28 @@ namespace NzbDrone.Core.Indexers.Newznab
             return results;
         }
 
+        protected override List<string> GetLanguages(XElement item)
+        {
+            var languges = TryGetMultipleNewznabAttributes(item, "language");
+            var results = new List<string>();
+
+            // Try to find <language> elements for some indexers that suck at following the rules.
+            if (languges.Count == 0)
+            {
+                languges = item.Elements("language").Select(e => e.Value).ToList();
+            }
+
+            foreach (var language in languges)
+            {
+                if (language.IsNotNullOrWhiteSpace())
+                {
+                    results.Add(language);
+                }
+            }
+
+            return results;
+        }
+
         protected override long GetSize(XElement item)
         {
             long size;

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

@@ -125,6 +125,28 @@ namespace NzbDrone.Core.Indexers.Torznab
             return ParseUrl(item.TryGetValue("comments"));
         }
 
+        protected override List<string> GetLanguages(XElement item)
+        {
+            var languges = TryGetMultipleTorznabAttributes(item, "language");
+            var results = new List<string>();
+
+            // Try to find <language> elements for some indexers that suck at following the rules.
+            if (languges.Count == 0)
+            {
+                languges = item.Elements("language").Select(e => e.Value).ToList();
+            }
+
+            foreach (var language in languges)
+            {
+                if (language.IsNotNullOrWhiteSpace())
+                {
+                    results.Add(language);
+                }
+            }
+
+            return results;
+        }
+
         protected override long GetSize(XElement item)
         {
             long size;

src/NzbDrone.Core/Indexers/RssParser.cs

@@ -166,6 +166,7 @@ namespace NzbDrone.Core.Indexers
             releaseInfo.InfoUrl = GetInfoUrl(item);
             releaseInfo.CommentUrl = GetCommentUrl(item);
             releaseInfo.Categories = GetCategory(item);
+            releaseInfo.Languages = GetLanguages(item);
 
             try
             {
@@ -237,6 +238,11 @@ namespace NzbDrone.Core.Indexers
             return ParseUrl((string)item.Element("comments"));
         }
 
+        protected virtual List<string> GetLanguages(XElement item)
+        {
+            return new List<string>();
+        }
+
         protected virtual long GetSize(XElement item)
         {
             if (UseEnclosureLength)