message: Add explanatory comments about the new code.
diff: @@ -352,6 +352,10 @@ async fn fetch_and_store_block_header(
  });
  }
  + // We're querying storage directly and short-circuting here (before using the fetcher)
  + // as joiners don't talk to joiners and in a network comprised only of joining nodes
  + // we would never move past the initial sync since we would wait on fetcher
  + // trying to query a peer for block but have no peers to query for the data.
  if let Some(stored_block_header) = ctx
  .effect_builder
  .get_block_header_from_storage(block_hash, false)
  @@ -379,6 +383,10 @@ async fn fetch_and_store_deploy(
  deploy_or_transfer_hash: DeployHash,
  ctx: &ChainSyncContext<'_>,
  ) -> Result<Box<Deploy>, FetcherError<Deploy>> {
  + // We're querying storage directly and short-circuting here (before using the fetcher)
  + // as joiners don't talk to joiners and in a network comprised only of joining nodes
  + // we would never move past the initial sync since we would wait on fetcher
  + // trying to query a peer for a deploy but have no peers to query for the data.
  if let Some((stored_deploy, _)) = ctx
  .effect_builder
  .get_deploy_and_metadata_from_storage(deploy_or_transfer_hash)
  @@ -715,6 +723,10 @@ async fn sync_trie_store_worker(
  /// Synchronizes the trie store under a given state root hash.
  async fn sync_trie_store(state_root_hash: Digest, ctx: &ChainSyncContext<'_>) -> Result<(), Error> {
  + // We're querying storage directly and short-circuting here (before using the fetcher)
  + // as joiners don't talk to joiners and in a network comprised only of joining nodes
  + // we would never move past the initial sync since we would wait on fetcher
  + // trying to query a peer for a trie but have no peers to query for the data.
  if let Ok(Some(_trie)) = ctx.effect_builder.get_trie_full(state_root_hash).await {
  return Ok(());
  }
  