Fix #1241.

beacon_chain/beacon_node.nim

@@ -263,27 +263,7 @@ proc init*(T: type BeaconNode,
 
   # This merely configures the BeaconSync
   # The traffic will be started when we join the network.
-  network.initBeaconSync(blockPool, enrForkId.forkDigest,
-    proc(signedBlock: SignedBeaconBlock) =
-      if signedBlock.message.slot.isEpoch:
-        # TODO this is a hack to make sure that lmd ghost is run regularly
-        #      while syncing blocks - it's poor form to keep it here though -
-        #      the logic should be moved elsewhere
-        # TODO why only when syncing? well, because the way the code is written
-        #      we require a connection to a boot node to start, and that boot
-        #      node will start syncing as part of connection setup - it looks
-        #      like it needs to finish syncing before the slot timer starts
-        #      ticking which is a problem: all the synced blocks will be added
-        #      to the block pool without any periodic head updates while this
-        #      process is ongoing (during a blank start for example), which
-        #      leads to an unhealthy buildup of blocks in the non-finalized part
-        #      of the block pool
-        # TODO is it a problem that someone sending us a block can force
-        #      a potentially expensive head resolution?
-        discard res.updateHead()
-
-      onBeaconBlock(res, signedBlock))
-
+  network.initBeaconSync(blockPool, enrForkId.forkDigest)
   return res
 
 proc onAttestation(node: BeaconNode, attestation: Attestation) =

beacon_chain/sync_protocol.nim

@@ -37,7 +37,6 @@ type
   BeaconSyncNetworkState* = ref object
     blockPool*: BlockPool
     forkDigest*: ForkDigest
-    onBeaconBlock*: BeaconBlockCallback
 
   BeaconSyncPeerState* = ref object
     initialStatusReceived*: bool
@@ -66,12 +65,6 @@ func disconnectReasonName(reason: uint64): string =
   elif reason == uint64(FaultOrError): "Fault or error"
   else: "Disconnected (" & $reason & ")"
 
-proc importBlocks(state: BeaconSyncNetworkState,
-                  blocks: openarray[SignedBeaconBlock]) {.gcsafe.} =
-  for blk in blocks:
-    state.onBeaconBlock(blk)
-  info "Forward sync imported blocks", len = blocks.len
-
 proc getCurrentStatus*(state: BeaconSyncNetworkState): StatusMsg {.gcsafe.} =
   let
     blockPool = state.blockPool
@@ -236,11 +229,8 @@ proc handleStatus(peer: Peer,
 
     peer.setStatusMsg(theirStatus)
 
-proc initBeaconSync*(network: Eth2Node,
-                     blockPool: BlockPool,
-                     forkDigest: ForkDigest,
-                     onBeaconBlock: BeaconBlockCallback) =
+proc initBeaconSync*(network: Eth2Node, blockPool: BlockPool,
+                     forkDigest: ForkDigest) =
   var networkState = network.protocolState(BeaconSync)
   networkState.blockPool = blockPool
   networkState.forkDigest = forkDigest
-  networkState.onBeaconBlock = onBeaconBlock