[Core] Fix prefetch magnets missing trackers

When adding magnets that have been prefetched the tracker details were
lost. A result of returning only the lt.torrent_info.metadata which
does not contain full torrent details, such as trackers.

- Modified torrentmanager prefetch_metadata to return dict instead of
  base64 encoded bencoded metadata dict...
  - Used a namedtuple to ease identifying tuple contents.
  - Updated tests to reflect changes with mock trackers added to
    test_torrent.file.torrent.

- Refactor TorrentInfo to accept dict instead of bytes and add
  a class method to accept metadata dict with lists of trackers.
  - Rename class arg from metainfo to torrent_file, matching
    lt.torrent_info.
  - Rename metadata property to correct name; metainfo.
  - Simplify class variable naming with _filedata and _metainfo for
    torrent file contents encoded and decoded respectively.

- Update GTK Add torrent dialog to pass trackers to TorrentInfo.

1 files changed, 7 insertions, 7 deletions

diff --git a/deluge/core/core.py b/deluge/core/core.py
index 91f9b8a38..9a19e3057 100644
--- a/deluge/core/core.py
+++ b/deluge/core/core.py
@@ -437,22 +437,22 @@ class Core(component.Component):
 
     @export
     def prefetch_magnet_metadata(self, magnet, timeout=30):
-        """Download the metadata for the magnet uri without adding torrent to deluge session.
+        """Download magnet metadata without adding to Deluge session.
+
+        Used by UIs to get magnet files for selection before adding to session.
 
         Args:
             magnet (str): The magnet uri.
-            timeout (int): Time to wait to recieve metadata from peers.
+            timeout (int): Number of seconds to wait before cancelling request.
 
         Returns:
-            Deferred: A tuple of (torrent_id (str), metadata (bytes)) for the magnet.
-
-            The metadata is base64 encoded.
+            Deferred: A tuple of (torrent_id (str), metadata (dict)) for the magnet.
 
         """
 
         def on_metadata(result, result_d):
-            torrent_id, metadata = result
-            result_d.callback((torrent_id, b64encode(metadata)))
+            """Return result of torrent_id and metadata"""
+            result_d.callback(result)
             return result
 
         d = self.torrentmanager.prefetch_metadata(magnet, timeout)