Fixed: Magnet downloads weren't being started on RTorrent.

src/NzbDrone.Core/Download/Clients/rTorrent/RTorrent.cs

@@ -41,26 +41,30 @@ namespace NzbDrone.Core.Download.Clients.RTorrent
         {
             _proxy.AddTorrentFromUrl(magnetLink, Settings);
 
-            var tries = 10;
-            var retryDelay = 500;
-            if (WaitForTorrent(hash, tries, retryDelay))
-            {
+            // Download the magnet to the appropriate directory.
             _proxy.SetTorrentLabel(hash, Settings.TvCategory, Settings);
-
             SetPriority(remoteEpisode, hash);
             SetDownloadDirectory(hash);
 
+            // Once the magnet meta download finishes, rTorrent replaces it with the actual torrent download with default settings.
+            // Schedule an event to apply the appropriate settings when that happens.
+            var priority = (RTorrentPriority)(remoteEpisode.IsRecentEpisode() ? Settings.RecentTvPriority : Settings.OlderTvPriority);
+            _proxy.SetDeferredMagnetProperties(hash, Settings.TvCategory, Settings.TvDirectory, priority, Settings);
+
             _proxy.StartTorrent(hash, Settings);
 
+            // Wait for the magnet to be resolved.
+            var tries = 10;
+            var retryDelay = 500;
+            if (WaitForTorrent(hash, tries, retryDelay))
+            {
                 return hash;
             }
             else
             {
-                _logger.Debug("rTorrent could not resolve magnet {0}. Removing", magnetLink);
+                _logger.Warn("rTorrent could not resolve magnet within {0} seconds, download may remain stuck: {1}.", tries * retryDelay / 1000, magnetLink);
 
-                RemoveItem(hash, true);
-
-                return null;
+                return hash;
             }
         }
 

src/NzbDrone.Core/Download/Clients/rTorrent/RTorrentProxy.cs

@@ -21,6 +21,7 @@ namespace NzbDrone.Core.Download.Clients.RTorrent
         void SetTorrentDownloadDirectory(string hash, string directory, RTorrentSettings settings);
         bool HasHashTorrent(string hash, RTorrentSettings settings);
         void StartTorrent(string hash, RTorrentSettings settings);
+        void SetDeferredMagnetProperties(string hash, string category, string directory, RTorrentPriority priority, RTorrentSettings settings);
     }
 
     public interface IRTorrent : IXmlRpcProxy
@@ -46,6 +47,9 @@ namespace NzbDrone.Core.Download.Clients.RTorrent
         [XmlRpcMethod("d.directory.set")]
         int SetDirectory(string hash, string directory);
 
+        [XmlRpcMethod("system.method.set_key")]
+        int SetKey(string key, string cmd_key, string value);
+
         [XmlRpcMethod("d.name")]
         string GetName(string hash);
 
@@ -198,6 +202,49 @@ namespace NzbDrone.Core.Download.Clients.RTorrent
             }
         }
 
+        public void SetDeferredMagnetProperties(string hash, string category, string directory, RTorrentPriority priority, RTorrentSettings settings)
+        {
+            var commands = new List<string>();
+
+            if (category.IsNotNullOrWhiteSpace())
+            {
+                commands.Add("d.set_custom1=" + category);
+            }
+
+            if (directory.IsNotNullOrWhiteSpace())
+            {
+                commands.Add("d.set_directory=" + directory);
+            }
+
+            if (priority != RTorrentPriority.Normal)
+            {
+                commands.Add("d.set_priority=" + (long)priority);
+            }
+
+            if (commands.Any())
+            {
+                var key = "event.download.inserted";
+                var cmd_key = "sonarr_deferred_" + hash;
+
+                commands.Add(string.Format("print=\"Applying deferred properties to {0}\"", hash));
+
+                // Remove event handler once triggered.
+                commands.Add(string.Format("\"system.method.set_key={0},{1}\"", key, cmd_key));
+
+                var setKeyValue = string.Format("branch=\"equal=d.get_hash=,cat={0}\",{{{1}}}", hash, string.Join(",", commands));
+
+                _logger.Debug("Executing remote method: method.set_key = {0},{1},{2}", key, cmd_key, setKeyValue);
+
+                var client = BuildClient(settings);
+
+                var response = client.SetKey(key, cmd_key, setKeyValue);
+                if (response != 0)
+                {
+                    throw new DownloadClientException("Could set properties for torrent: {0}.", hash);
+                }
+            }
+        }
+
         public bool HasHashTorrent(string hash, RTorrentSettings settings)
         {
             _logger.Debug("Executing remote method: d.name");