minor Merge and forkchoice updates release

Makefile

@@ -97,12 +97,12 @@ install_test:
 # Testing against `minimal` config by default
 test: pyspec
 	. venv/bin/activate; cd $(PY_SPEC_DIR); \
-	python3 -m pytest -n 4 --disable-bls --cov=eth2spec.phase0.minimal --cov=eth2spec.altair.minimal --cov-report="html:$(COV_HTML_OUT)" --cov-branch eth2spec
+	python3 -m pytest -n 4 --disable-bls --cov=eth2spec.phase0.minimal --cov=eth2spec.altair.minimal --cov=eth2spec.merge.minimal --cov-report="html:$(COV_HTML_OUT)" --cov-branch eth2spec
 
 # Testing against `minimal` config by default
 find_test: pyspec
 	. venv/bin/activate; cd $(PY_SPEC_DIR); \
-	python3 -m pytest -k=$(K) --disable-bls --cov=eth2spec.phase0.minimal --cov=eth2spec.altair.minimal --cov-report="html:$(COV_HTML_OUT)" --cov-branch eth2spec
+	python3 -m pytest -k=$(K) --disable-bls --cov=eth2spec.phase0.minimal --cov=eth2spec.altair.minimal --cov=eth2spec.merge.minimal --cov-report="html:$(COV_HTML_OUT)" --cov-branch eth2spec
 
 citest: pyspec
 	mkdir -p tests/core/pyspec/test-reports/eth2spec;

configs/mainnet.yaml

@@ -70,6 +70,11 @@ MIN_PER_EPOCH_CHURN_LIMIT: 4
 CHURN_LIMIT_QUOTIENT: 65536
 
 
+# Fork choice
+# ---------------------------------------------------------------
+# 70%
+PROPOSER_SCORE_BOOST: 70
+
 # Deposit contract
 # ---------------------------------------------------------------
 # Ethereum PoW Mainnet

configs/minimal.yaml

@@ -69,6 +69,12 @@ MIN_PER_EPOCH_CHURN_LIMIT: 4
 CHURN_LIMIT_QUOTIENT: 32
 
 
+# Fork choice
+# ---------------------------------------------------------------
+# 70%
+PROPOSER_SCORE_BOOST: 70
+
+
 # Deposit contract
 # ---------------------------------------------------------------
 # Ethereum Goerli testnet

setup.py

@@ -511,7 +511,7 @@ def sundry_functions(cls) -> str:
 
 
 def get_pow_block(hash: Bytes32) -> Optional[PowBlock]:
-    return PowBlock(block_hash=hash, parent_hash=Bytes32(), total_difficulty=uint256(0), difficulty=uint256(0))
+    return PowBlock(block_hash=hash, parent_hash=Bytes32(), total_difficulty=uint256(0))
 
 
 def get_execution_state(execution_state_root: Bytes32) -> ExecutionState:

specs/altair/beacon-chain.md

@@ -685,7 +685,7 @@ This helper function is only for initializing the state for pure Altair testnets
 *Note*: The function `initialize_beacon_state_from_eth1` is modified: (1) using `ALTAIR_FORK_VERSION` as the current fork version, (2) utilizing the Altair `BeaconBlockBody` when constructing the initial `latest_block_header`, and (3) adding initial sync committees.
 
 ```python
-def initialize_beacon_state_from_eth1(eth1_block_hash: Bytes32,
+def initialize_beacon_state_from_eth1(eth1_block_hash: Hash32,
                                       eth1_timestamp: uint64,
                                       deposits: Sequence[Deposit]) -> BeaconState:
     fork = Fork(

specs/merge/beacon-chain.md

@@ -24,8 +24,8 @@
     - [`ExecutionPayloadHeader`](#executionpayloadheader)
 - [Helper functions](#helper-functions)
   - [Predicates](#predicates)
-    - [`is_merge_complete`](#is_merge_complete)
-    - [`is_merge_block`](#is_merge_block)
+    - [`is_merge_transition_complete`](#is_merge_transition_complete)
+    - [`is_merge_transition_block`](#is_merge_transition_block)
     - [`is_execution_enabled`](#is_execution_enabled)
   - [Misc](#misc)
     - [`compute_timestamp_at_slot`](#compute_timestamp_at_slot)
@@ -167,7 +167,7 @@ class BeaconState(Container):
 class ExecutionPayload(Container):
     # Execution block header fields
     parent_hash: Hash32
-    coinbase: ExecutionAddress  # 'beneficiary' in the yellow paper
+    fee_recipient: ExecutionAddress  # 'beneficiary' in the yellow paper
     state_root: Bytes32
     receipt_root: Bytes32  # 'receipts root' in the yellow paper
     logs_bloom: ByteVector[BYTES_PER_LOGS_BLOOM]
@@ -189,7 +189,7 @@ class ExecutionPayload(Container):
 class ExecutionPayloadHeader(Container):
     # Execution block header fields
     parent_hash: Hash32
-    coinbase: ExecutionAddress
+    fee_recipient: ExecutionAddress
     state_root: Bytes32
     receipt_root: Bytes32
     logs_bloom: ByteVector[BYTES_PER_LOGS_BLOOM]
@@ -209,25 +209,25 @@ class ExecutionPayloadHeader(Container):
 
 ### Predicates
 
-#### `is_merge_complete`
+#### `is_merge_transition_complete`
 
 ```python
-def is_merge_complete(state: BeaconState) -> bool:
+def is_merge_transition_complete(state: BeaconState) -> bool:
     return state.latest_execution_payload_header != ExecutionPayloadHeader()
 ```
 
-#### `is_merge_block`
+#### `is_merge_transition_block`
 
 ```python
-def is_merge_block(state: BeaconState, body: BeaconBlockBody) -> bool:
-    return not is_merge_complete(state) and body.execution_payload != ExecutionPayload()
+def is_merge_transition_block(state: BeaconState, body: BeaconBlockBody) -> bool:
+    return not is_merge_transition_complete(state) and body.execution_payload != ExecutionPayload()
 ```
 
 #### `is_execution_enabled`
 
 ```python
 def is_execution_enabled(state: BeaconState, body: BeaconBlockBody) -> bool:
-    return is_merge_block(state, body) or is_merge_complete(state)
+    return is_merge_transition_block(state, body) or is_merge_transition_complete(state)
 ```
 
 ### Misc
@@ -346,7 +346,7 @@ def process_block(state: BeaconState, block: BeaconBlock) -> None:
 ```python
 def process_execution_payload(state: BeaconState, payload: ExecutionPayload, execution_engine: ExecutionEngine) -> None:
     # Verify consistency of the parent hash with respect to the previous execution payload header
-    if is_merge_complete(state):
+    if is_merge_transition_complete(state):
         assert payload.parent_hash == state.latest_execution_payload_header.block_hash
     # Verify random
     assert payload.random == get_randao_mix(state, get_current_epoch(state))
@@ -357,7 +357,7 @@ def process_execution_payload(state: BeaconState, payload: ExecutionPayload, exe
     # Cache execution payload header
     state.latest_execution_payload_header = ExecutionPayloadHeader(
         parent_hash=payload.parent_hash,
-        coinbase=payload.coinbase,
+        fee_recipient=payload.fee_recipient,
         state_root=payload.state_root,
         receipt_root=payload.receipt_root,
         logs_bloom=payload.logs_bloom,
@@ -406,7 +406,7 @@ Modifications include:
   Else, the Merge starts from genesis and the transition is incomplete.
 
 ```python
-def initialize_beacon_state_from_eth1(eth1_block_hash: Bytes32,
+def initialize_beacon_state_from_eth1(eth1_block_hash: Hash32,
                                       eth1_timestamp: uint64,
                                       deposits: Sequence[Deposit],
                                       execution_payload_header: ExecutionPayloadHeader=ExecutionPayloadHeader()

specs/merge/fork-choice.md

@@ -77,7 +77,7 @@ Used to signal to initiate the payload build process via `notify_forkchoice_upda
 class PayloadAttributes(object):
     timestamp: uint64
     random: Bytes32
-    fee_recipient: ExecutionAddress
+    suggested_fee_recipient: ExecutionAddress
 ```
 
 ### `PowBlock`
@@ -87,7 +87,6 @@ class PowBlock(Container):
     block_hash: Hash32
     parent_hash: Hash32
     total_difficulty: uint256
-    difficulty: uint256
 ```
 
 ### `get_pow_block`
@@ -168,14 +167,20 @@ def on_block(store: Store, signed_block: SignedBeaconBlock) -> None:
     state_transition(state, signed_block, True)
 
     # [New in Merge]
-    if is_merge_block(pre_state, block.body):
+    if is_merge_transition_block(pre_state, block.body):
         validate_merge_block(block)
 
     # Add new block to the store
     store.blocks[hash_tree_root(block)] = block
     # Add new state for this block to the store
     store.block_states[hash_tree_root(block)] = state
 
+    # Add proposer score boost if the block is timely
+    time_into_slot = (store.time - store.genesis_time) % SECONDS_PER_SLOT
+    is_before_attesting_interval = time_into_slot < SECONDS_PER_SLOT // INTERVALS_PER_SLOT
+    if get_current_slot(store) == block.slot and is_before_attesting_interval:
+        store.proposer_boost_root = hash_tree_root(block)
+
     # Update justified checkpoint
     if state.current_justified_checkpoint.epoch > store.justified_checkpoint.epoch:
         if state.current_justified_checkpoint.epoch > store.best_justified_checkpoint.epoch:
@@ -186,17 +191,5 @@ def on_block(store: Store, signed_block: SignedBeaconBlock) -> None:
     # Update finalized checkpoint
     if state.finalized_checkpoint.epoch > store.finalized_checkpoint.epoch:
         store.finalized_checkpoint = state.finalized_checkpoint
-
-        # Potentially update justified if different from store
-        if store.justified_checkpoint != state.current_justified_checkpoint:
-            # Update justified if new justified is later than store justified
-            if state.current_justified_checkpoint.epoch > store.justified_checkpoint.epoch:
-                store.justified_checkpoint = state.current_justified_checkpoint
-                return
-
-            # Update justified if store justified is not in chain with finalized checkpoint
-            finalized_slot = compute_start_slot_at_epoch(store.finalized_checkpoint.epoch)
-            ancestor_at_finalized_slot = get_ancestor(store, store.justified_checkpoint.root, finalized_slot)
-            if ancestor_at_finalized_slot != store.finalized_checkpoint.root:
-                store.justified_checkpoint = state.current_justified_checkpoint
+        store.justified_checkpoint = state.current_justified_checkpoint
 ```

specs/merge/validator.md

@@ -43,12 +43,16 @@ Please see related Beacon Chain doc before continuing and use them as a referenc
 ```python
 def get_pow_block_at_terminal_total_difficulty(pow_chain: Dict[Hash32, PowBlock]) -> Optional[PowBlock]:
     # `pow_chain` abstractly represents all blocks in the PoW chain
-    for block in pow_chain:
-        parent = pow_chain[block.parent_hash]
+    for block in pow_chain.values():
         block_reached_ttd = block.total_difficulty >= TERMINAL_TOTAL_DIFFICULTY
-        parent_reached_ttd = parent.total_difficulty >= TERMINAL_TOTAL_DIFFICULTY
-        if block_reached_ttd and not parent_reached_ttd:
-            return block
+        if block_reached_ttd:
+            # If genesis block, no parent exists so reaching TTD alone qualifies as valid terminal block
+            if block.parent_hash == Hash32():
+                return block
+            parent = pow_chain[block.parent_hash]
+            parent_reached_ttd = parent.total_difficulty >= TERMINAL_TOTAL_DIFFICULTY
+            if not parent_reached_ttd:
+                return block
 
     return None
 ```
@@ -106,22 +110,22 @@ All validator responsibilities remain unchanged other than those noted below. Na
 
 To obtain an execution payload, a block proposer building a block on top of a `state` must take the following actions:
 
-1. Set `payload_id = prepare_execution_payload(state, pow_chain, finalized_block_hash, fee_recipient, execution_engine)`, where:
+1. Set `payload_id = prepare_execution_payload(state, pow_chain, finalized_block_hash, suggested_fee_recipient, execution_engine)`, where:
     * `state` is the state object after applying `process_slots(state, slot)` transition to the resulting state of the parent block processing
     * `pow_chain` is a `Dict[Hash32, PowBlock]` dictionary that abstractly represents all blocks in the PoW chain with block hash as the dictionary key
     * `finalized_block_hash` is the hash of the latest finalized execution payload (`Hash32()` if none yet finalized)
-    * `fee_recipient` is the value suggested to be used for the `coinbase` field of the execution payload
+    * `suggested_fee_recipient` is the value suggested to be used for the `fee_recipient` field of the execution payload
 
 
 ```python
 def prepare_execution_payload(state: BeaconState,
                               pow_chain: Dict[Hash32, PowBlock],
                               finalized_block_hash: Hash32,
-                              fee_recipient: ExecutionAddress,
+                              suggested_fee_recipient: ExecutionAddress,
                               execution_engine: ExecutionEngine) -> Optional[PayloadId]:
-    if not is_merge_complete(state):
+    if not is_merge_transition_complete(state):
         is_terminal_block_hash_set = TERMINAL_BLOCK_HASH != Hash32()
-        is_activation_epoch_reached = get_current_epoch(state.slot) >= TERMINAL_BLOCK_HASH_ACTIVATION_EPOCH
+        is_activation_epoch_reached = get_current_epoch(state) >= TERMINAL_BLOCK_HASH_ACTIVATION_EPOCH
         if is_terminal_block_hash_set and not is_activation_epoch_reached:
             # Terminal block hash is set but activation epoch is not yet reached, no prepare payload call is needed
             return None
@@ -140,7 +144,7 @@ def prepare_execution_payload(state: BeaconState,
     payload_attributes = PayloadAttributes(
         timestamp=compute_timestamp_at_slot(state, state.slot),
         random=get_randao_mix(state, get_current_epoch(state)),
-        fee_recipient=fee_recipient,
+        suggested_fee_recipient=suggested_fee_recipient,
     )
     return execution_engine.notify_forkchoice_updated(parent_hash, finalized_block_hash, payload_attributes)
 ```

specs/phase0/beacon-chain.md

@@ -169,7 +169,6 @@ We define the following Python custom types for type hinting and readability:
 | `BLSPubkey` | `Bytes48` | a BLS12-381 public key |
 | `BLSSignature` | `Bytes96` | a BLS12-381 signature |
 
-
 ## Constants
 
 The following values are (non-configurable) constants used throughout the specification.
@@ -1175,7 +1174,7 @@ Before the Ethereum beacon chain genesis has been triggered, and for every Ether
 Proof-of-work blocks must only be considered once they are at least `SECONDS_PER_ETH1_BLOCK * ETH1_FOLLOW_DISTANCE` seconds old (i.e. `eth1_timestamp + SECONDS_PER_ETH1_BLOCK * ETH1_FOLLOW_DISTANCE <= current_unix_time`). Due to this constraint, if `GENESIS_DELAY < SECONDS_PER_ETH1_BLOCK * ETH1_FOLLOW_DISTANCE`, then the `genesis_time` can happen before the time/state is first known. Values should be configured to avoid this case.
 
 ```python
-def initialize_beacon_state_from_eth1(eth1_block_hash: Bytes32,
+def initialize_beacon_state_from_eth1(eth1_block_hash: Hash32,
                                       eth1_timestamp: uint64,
                                       deposits: Sequence[Deposit]) -> BeaconState:
     fork = Fork(