EIP-3529 fixes (#2026)

* Calculate gas_used in frontier vm initialization, use MAX_REFUND_QUOTIENT throughout

* Standardize make_receipt between Berlin and Byzantium

Author: kclowes

eth/vm/forks/berlin/__init__.py

@@ -2,21 +2,10 @@
     Type,
 )
 
-from eth.abc import (
-    BlockHeaderAPI,
-    ComputationAPI,
-    ReceiptAPI,
-    SignedTransactionAPI,
-    StateAPI,
-)
 from eth.rlp.blocks import BaseBlock
 from eth.vm.forks import (
     MuirGlacierVM,
 )
-from eth.vm.forks.byzantium.constants import (
-    EIP658_TRANSACTION_STATUS_CODE_FAILURE,
-    EIP658_TRANSACTION_STATUS_CODE_SUCCESS,
-)
 from eth.vm.state import BaseState
 
 from .blocks import BerlinBlock
@@ -28,17 +17,6 @@
 from .state import BerlinState
 
 
-def finalize_gas_used(transaction: SignedTransactionAPI, computation: ComputationAPI) -> int:
-    gas_remaining = computation.get_gas_remaining()
-    consumed_gas = transaction.gas - gas_remaining
-
-    gross_refund = computation.get_gas_refund()
-    max_refund = consumed_gas // 2
-    gas_refund = min(gross_refund, max_refund)
-
-    return consumed_gas - gas_refund
-
-
 class BerlinVM(MuirGlacierVM):
     # fork name
     fork = 'berlin'
@@ -51,19 +29,3 @@ class BerlinVM(MuirGlacierVM):
     create_header_from_parent = staticmethod(create_berlin_header_from_parent)  # type: ignore
     compute_difficulty = staticmethod(compute_berlin_difficulty)    # type: ignore
     configure_header = configure_berlin_header
-
-    @staticmethod
-    def make_receipt(
-            base_header: BlockHeaderAPI,
-            transaction: SignedTransactionAPI,
-            computation: ComputationAPI,
-            state: StateAPI) -> ReceiptAPI:
-
-        gas_used = base_header.gas_used + finalize_gas_used(transaction, computation)
-
-        if computation.is_error:
-            status_code = EIP658_TRANSACTION_STATUS_CODE_FAILURE
-        else:
-            status_code = EIP658_TRANSACTION_STATUS_CODE_SUCCESS
-
-        return transaction.make_receipt(status_code, gas_used, computation.get_log_entries())

eth/vm/forks/byzantium/__init__.py

@@ -28,7 +28,6 @@
     validate_lte,
 )
 from eth.vm.forks.spurious_dragon import SpuriousDragonVM
-from eth.vm.forks.frontier import make_frontier_receipt
 
 from .blocks import ByzantiumBlock
 from .constants import (
@@ -100,18 +99,19 @@ def add_receipt_to_header(self,
             gas_used=receipt.gas_used,
         )
 
-    @staticmethod
+    @classmethod
     def make_receipt(
+            cls,
             base_header: BlockHeaderAPI,
             transaction: SignedTransactionAPI,
             computation: ComputationAPI,
             state: StateAPI) -> ReceiptAPI:
 
-        receipt_without_state_root = make_frontier_receipt(base_header, transaction, computation)
+        gas_used = base_header.gas_used + cls.finalize_gas_used(transaction, computation)
 
         if computation.is_error:
             status_code = EIP658_TRANSACTION_STATUS_CODE_FAILURE
         else:
             status_code = EIP658_TRANSACTION_STATUS_CODE_SUCCESS
 
-        return receipt_without_state_root.copy(state_root=status_code)
+        return transaction.make_receipt(status_code, gas_used, computation.get_log_entries())

eth/vm/forks/frontier/__init__.py

@@ -25,6 +25,7 @@
 from eth.vm.base import VM
 
 from .blocks import FrontierBlock
+from .constants import MAX_REFUND_QUOTIENT
 from .state import FrontierState
 from .headers import (
     create_frontier_header_from_parent,
@@ -34,9 +35,8 @@
 from .validation import validate_frontier_transaction_against_header
 
 
-def make_frontier_receipt(base_header: BlockHeaderAPI,
-                          transaction: SignedTransactionAPI,
-                          computation: ComputationAPI) -> ReceiptAPI:
+def make_frontier_receipt(computation: ComputationAPI,
+                          new_cumulative_gas_used: int) -> ReceiptAPI:
     # Reusable for other forks
     # This skips setting the state root (set to 0 instead). The logic for making a state root
     # lives in the FrontierVM, so that state merkelization at each receipt is skipped at Byzantium+.
@@ -47,19 +47,9 @@ def make_frontier_receipt(base_header: BlockHeaderAPI,
         in computation.get_log_entries()
     ]
 
-    gas_remaining = computation.get_gas_remaining()
-    gas_refund = computation.get_gas_refund()
-    tx_gas_used = (
-        transaction.gas - gas_remaining
-    ) - min(
-        gas_refund,
-        (transaction.gas - gas_remaining) // 2,
-    )
-    gas_used = base_header.gas_used + tx_gas_used
-
     receipt = Receipt(
         state_root=ZERO_HASH32,
-        gas_used=gas_used,
+        gas_used=new_cumulative_gas_used,
         logs=logs,
     )
 
@@ -103,14 +93,35 @@ def add_receipt_to_header(self,
             state_root=self.state.make_state_root(),
         )
 
-    @staticmethod
+    @classmethod
+    def calculate_net_gas_refund(cls, consumed_gas: int, gross_refund: int) -> int:
+        max_refund = consumed_gas // MAX_REFUND_QUOTIENT
+        return min(max_refund, gross_refund)
+
+    @classmethod
+    def finalize_gas_used(cls,
+                          transaction: SignedTransactionAPI,
+                          computation: ComputationAPI) -> int:
+
+        gas_remaining = computation.get_gas_remaining()
+        consumed_gas = transaction.gas - gas_remaining
+
+        gross_refund = computation.get_gas_refund()
+        net_refund = cls.calculate_net_gas_refund(consumed_gas, gross_refund)
+
+        return consumed_gas - net_refund
+
+    @classmethod
     def make_receipt(
+            cls,
             base_header: BlockHeaderAPI,
             transaction: SignedTransactionAPI,
             computation: ComputationAPI,
             state: StateAPI) -> ReceiptAPI:
 
-        receipt_without_state_root = make_frontier_receipt(base_header, transaction, computation)
+        gas_used = base_header.gas_used + cls.finalize_gas_used(transaction, computation)
+
+        receipt_without_state_root = make_frontier_receipt(computation, gas_used)
 
         return receipt_without_state_root.copy(
             state_root=state.make_state_root()

eth/vm/forks/frontier/constants.py

@@ -1,2 +1,4 @@
 FRONTIER_DIFFICULTY_ADJUSTMENT_CUTOFF = 13
 REFUND_SELFDESTRUCT = 24000
+
+MAX_REFUND_QUOTIENT = 2

eth/vm/forks/frontier/state.py

@@ -35,7 +35,10 @@
 
 
 from .computation import FrontierComputation
-from .constants import REFUND_SELFDESTRUCT
+from .constants import (
+    REFUND_SELFDESTRUCT,
+    MAX_REFUND_QUOTIENT,
+)
 from .transaction_context import (
     FrontierTransactionContext
 )
@@ -154,7 +157,7 @@ def calculate_gas_refund(cls,
         # Gas Refunds
         gas_refunded = computation.get_gas_refund()
 
-        return min(gas_refunded, gas_used // 2)
+        return min(gas_refunded, gas_used // MAX_REFUND_QUOTIENT)
 
     def finalize_computation(self,
                              transaction: SignedTransactionAPI,

eth/vm/forks/london/__init__.py

@@ -12,6 +12,7 @@
 
 from .blocks import LondonBlock
 from .constants import (
+    EIP3529_MAX_REFUND_QUOTIENT,
     ELASTICITY_MULTIPLIER,
 )
 from .headers import (
@@ -59,3 +60,8 @@ def validate_gas(
                 f"Header has invalid base fee per gas (has {header.base_fee_per_gas}"
                 f", expected {expected_base_fee_per_gas})"
             )
+
+    @classmethod
+    def calculate_net_gas_refund(cls, consumed_gas: int, gross_refund: int) -> int:
+        max_refund = consumed_gas // EIP3529_MAX_REFUND_QUOTIENT
+        return min(max_refund, gross_refund)

newsfragments/2026.bugfix.rst

@@ -0,0 +1 @@
+Add EIP-3529 refund reduction to make_receipt logic.