Merge pull request #3564 from lbryio/fix_downloader_losing_peers

fix handling re-adding lost peers during download

lbry/blob_exchange/downloader.py

@@ -97,21 +97,15 @@ async def download_blob(self, blob_hash: str, length: typing.Optional[int] = Non
                     "%s running, %d peers, %d ignored, %d active, %s connections", blob_hash[:6],
                     len(batch), len(self.ignored), len(self.active_connections), len(self.connections)
                 )
-                re_add: typing.Set['KademliaPeer'] = set()
                 for peer in sorted(batch, key=lambda peer: self.scores.get(peer, 0), reverse=True):
                     if peer in self.ignored:
                         continue
-                    if peer in self.active_connections:
-                        if peer not in re_add:
-                            re_add.add(peer)
+                    if peer in self.active_connections or not self.should_race_continue(blob):
                         continue
-                    if not self.should_race_continue(blob):
-                        break
                     log.debug("request %s from %s:%i", blob_hash[:8], peer.address, peer.tcp_port)
                     t = self.loop.create_task(self.request_blob_from_peer(blob, peer, connection_id))
                     self.active_connections[peer] = t
-                if not re_add:
-                    self.peer_queue.put_nowait(list(batch))
+                self.peer_queue.put_nowait(list(batch))
                 await self.new_peer_or_finished()
                 self.cleanup_active()
             log.debug("downloaded %s", blob_hash[:8])