message: NO-TICK: Correct parent summary for the first block after Genesis.
diff: @@ -269,12 +269,18 @@ impl BlockExecutor {
  fn create_block(&mut self, finalized_block: FinalizedBlock, post_state_hash: Digest) -> Block {
  let proto_parent_hash = finalized_block.proto_block().parent_hash();
  - let parent_summary = self
  - .parent_map
  + // TODO: Compare finalized block's height as well.
  + let parent_summary_hash = if proto_parent_hash == &Default::default() {
  + // Genesis, no parent summary.
  + BlockHash::new(Digest::default())
  + } else {
  + self.parent_map
  .remove(proto_parent_hash)
  - .unwrap_or_else(|| panic!("failed to take {}", proto_parent_hash));
  + .unwrap_or_else(|| panic!("failed to take {}", proto_parent_hash))
  + .hash
  + };
  let new_proto_hash = *finalized_block.proto_block().hash();
  - let block = Block::new(parent_summary.hash, post_state_hash, finalized_block);
  + let block = Block::new(parent_summary_hash, post_state_hash, finalized_block);
  let summary = ExecutedBlockSummary {
  hash: *block.hash(),
  post_state_hash,
  