Fix vmflags for witness generation 1934. (#1961)

* Fix issue causing vmflags to be reset during call to processBlocks and enable witness generation in test_blockchain_json test.

* Fix copyright notice on updated files.

nimbus/evm/state.nim

@@ -1,5 +1,5 @@
 # Nimbus
-# Copyright (c) 2018-2023 Status Research & Development GmbH
+# Copyright (c) 2018-2024 Status Research & Development GmbH
 # Licensed under either of
 # * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or
 # http:https://www.apache.org/licenses/LICENSE-2.0)
@@ -27,7 +27,8 @@ proc init(
  blockCtx: BlockContext;
  com: CommonRef;
  tracer: TracerRef,
- asyncFactory: AsyncOperationFactory = AsyncOperationFactory(maybeDataSource: none[AsyncDataSource]()))
+ asyncFactory: AsyncOperationFactory = AsyncOperationFactory(maybeDataSource: none[AsyncDataSource]()),
+ flags: set[VMFlag] = self.flags)
  {.gcsafe.} =
  ## Initialisation helper
  self.parent = parent
@@ -37,6 +38,7 @@ proc init(
  self.tracer = tracer
  self.stateDB = ac
  self.asyncFactory = asyncFactory
+ self.flags = flags
 
 func blockCtx(com: CommonRef, header: BlockHeader):
  BlockContext {.gcsafe, raises: [CatchableError].} =
@@ -102,13 +104,15 @@ proc reinit*(self: BaseVMState; ## Object descriptor
  db = com.db
  ac = if self.stateDB.rootHash == parent.stateRoot: self.stateDB
  else: com.ledgerType.init(db, parent.stateRoot, com.pruneTrie)
+ flags = self.flags
  self[].reset
  self.init(
  ac = ac,
  parent = parent,
  blockCtx = blockCtx,
  com = com,
- tracer = tracer)
+ tracer = tracer,
+ flags = flags)
  return true
  # else: false
 
@@ -283,15 +287,19 @@ proc generateWitness*(vmState: BaseVMState): bool =
  GenerateWitness in vmState.flags
 
 proc `generateWitness=`*(vmState: BaseVMState, status: bool) =
- if status: vmState.flags.incl GenerateWitness
- else: vmState.flags.excl GenerateWitness
+  if status: vmState.flags.incl GenerateWitness
+  else: vmState.flags.excl GenerateWitness
 
 proc buildWitness*(vmState: BaseVMState): seq[byte]
  {.raises: [CatchableError].} =
  let rootHash = vmState.stateDB.rootHash
  let mkeys = vmState.stateDB.makeMultiKeys()
  let flags = if vmState.fork >= FkSpurious: {wfEIP170} else: {}
 
+ # A valid block having no transactions should return an empty witness
+ if mkeys.keys.len() == 0:
+ return @[]
+
  # build witness from tree
  var wb = initWitnessBuilder(vmState.com.db, rootHash, flags)
  wb.buildWitness(mkeys)

tests/test_blockchain_json.nim

@@ -1,5 +1,5 @@
 # Nimbus
-# Copyright (c) 2018-2023 Status Research & Development GmbH
+# Copyright (c) 2018-2024 Status Research & Development GmbH
 # Licensed under either of
 # * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or
 # http:https://www.apache.org/licenses/LICENSE-2.0)
@@ -176,6 +176,12 @@ proc parseTestCtx(fixture: JsonNode, testStatusIMPL: var TestStatus): TestCtx =
 proc blockWitness(vmState: BaseVMState, chainDB: CoreDbRef) =
  let rootHash = vmState.stateDB.rootHash
  let witness = vmState.buildWitness()
+
+ if witness.len() == 0:
+ if vmState.stateDB.makeMultiKeys().keys.len() != 0:
+ raise newException(ValidationError, "Invalid trie generated from block witness")
+ return
+
  let fork = vmState.fork
  let flags = if fork >= FKSpurious: {wfEIP170} else: {}
 
@@ -221,6 +227,7 @@ proc importBlock(ctx: var TestCtx, com: CommonRef,
  com,
  tracerInst,
  )
+ ctx.vmState.generateWitness = true # Enable saving witness data
 
  let
  chain = newChain(com, extraValidation = true, ctx.vmState)
@@ -229,8 +236,7 @@ proc importBlock(ctx: var TestCtx, com: CommonRef,
  if res == ValidationResult.Error:
  raise newException(ValidationError, "persistBlocks validation")
  else:
- if ctx.vmState.generateWitness():
- blockWitness(ctx.vmState, com.db)
+ blockWitness(chain.vmState, com.db)
 
 proc applyFixtureBlockToChain(ctx: var TestCtx, tb: var TestBlock,
  com: CommonRef, checkSeal: bool) =