core/state: modify how self-destruct journalling works

The self-destruct journalling is a bit strange: we allow the
'selfdestruct' operation to be journalled several times. This makes it
so that we also are forced to store whether the account was
already destructed.
What we can do instead, is to only journal the first destruction, and after
that only journal balance-changes, but not journal the selfdestruct itself.

This simplifies the journalling, so that internals about state management
does not leak into the journal-API.

Author: holiman

core/state/journal.go

@@ -144,12 +144,8 @@ func (j *journal) JournalCreate(addr common.Address) {
 	j.append(createObjectChange{account: &addr})
 }
 
-func (j *journal) JournalDestruct(addr common.Address, previouslyDestructed bool, prevBalance *uint256.Int) {
-	j.append(selfDestructChange{
-		account:     &addr,
-		prev:        previouslyDestructed,
-		prevbalance: prevBalance.Clone(),
-	})
+func (j *journal) JournalDestruct(addr common.Address) {
+	j.append(selfDestructChange{account: &addr})
 }
 
 func (j *journal) JournalSetState(addr common.Address, key, prev common.Hash) {
@@ -241,9 +237,7 @@ type (
 		prevStorageOrigin      map[common.Hash][]byte
 	}
 	selfDestructChange struct {
-		account     *common.Address
-		prev        bool // whether account had already self-destructed
-		prevbalance *uint256.Int
+		account *common.Address
 	}
 
 	// Changes to individual accounts.
@@ -326,8 +320,7 @@ func (ch resetObjectChange) dirtied() *common.Address {
 func (ch selfDestructChange) revert(s *StateDB) {
 	obj := s.getStateObject(*ch.account)
 	if obj != nil {
-		obj.selfDestructed = ch.prev
-		obj.setBalance(ch.prevbalance)
+		obj.selfDestructed = false
 	}
 }
 

core/state/statedb.go

@@ -439,9 +439,17 @@ func (s *StateDB) SelfDestruct(addr common.Address) {
 	if stateObject == nil {
 		return
 	}
-	s.journal.JournalDestruct(addr, stateObject.selfDestructed, stateObject.Balance())
-	stateObject.markSelfdestructed()
-	stateObject.data.Balance = new(uint256.Int)
+	// Regardless of whether it is already destructed or not, we do have to
+	// journal the balance-change, if we set it to zero here.
+	if !stateObject.Balance().IsZero() {
+		stateObject.SetBalance(new(uint256.Int))
+	}
+	// If it is already marked as self-destructed, we do not need to add it
+	// for journalling a second time.
+	if !stateObject.selfDestructed {
+		s.journal.JournalDestruct(addr)
+		stateObject.markSelfdestructed()
+	}
 }
 
 func (s *StateDB) Selfdestruct6780(addr common.Address) {