Merge pull request #4770 from xoriole/fix-metainfo-error-4765

Fixed metainfo issue for torrents already in credit mining mode

Tribler/Core/Libtorrent/LibtorrentMgr.py

@@ -451,8 +451,11 @@ def get_metainfo(self, infohash, timeout=30):
         elif infohash not in self.metainfo_requests:
             metainfo_deferred = Deferred()
 
-            # Are we already downloading the torrent? If so, use that handle
-            if infohash_hex in self.torrents and self.torrents[infohash_hex][0].handle:
+            # Are we already downloading the torrent? If so, use that handle.
+            # Note that if the download is already in credit mining mode and has not started then it will not
+            # have metadata.
+            if infohash_hex in self.torrents and self.torrents[infohash_hex][0].handle \
+                    and self.torrents[infohash_hex][0].handle.has_metadata():
                 handle = self.torrents[infohash_hex][0].handle
                 self.metainfo_requests[infohash] = (handle, [metainfo_deferred])
                 self.check_metainfo(infohash_hex)