core: fix two snapshot iterator flaws, decollide snap storage prefix

* core/state/snapshot/iterator: fix two disk iterator flaws

* core/rawdb: change SnapshotStoragePrefix to avoid prefix collision with preimagePrefix

core/state/journal.go

@@ -90,7 +90,8 @@ type (
 		account *common.Address
 	}
 	resetObjectChange struct {
-		prev *stateObject
+		prev         *stateObject
+		prevdestruct bool
 	}
 	suicideChange struct {
 		account     *common.Address
@@ -142,6 +143,9 @@ func (ch createObjectChange) dirtied() *common.Address {
 
 func (ch resetObjectChange) revert(s *StateDB) {
 	s.setStateObject(ch.prev)
+	if !ch.prevdestruct && s.snap != nil {
+		delete(s.snapDestructs, ch.prev.addrHash)
+	}
 }
 
 func (ch resetObjectChange) dirtied() *common.Address {

core/state/snapshot/iterator.go

@@ -148,9 +148,10 @@ type diskAccountIterator struct {
 
 // AccountIterator creates an account iterator over a disk layer.
 func (dl *diskLayer) AccountIterator(seek common.Hash) AccountIterator {
+	// TODO: Fix seek position, or remove seek parameter
 	return &diskAccountIterator{
 		layer: dl,
-		it:    dl.diskdb.NewIteratorWithPrefix(append(rawdb.SnapshotAccountPrefix, seek[:]...)),
+		it:    dl.diskdb.NewIteratorWithPrefix(rawdb.SnapshotAccountPrefix),
 	}
 }
 
@@ -160,11 +161,16 @@ func (it *diskAccountIterator) Next() bool {
 	if it.it == nil {
 		return false
 	}
-	// Try to advance the iterator and release it if we reahed the end
-	if !it.it.Next() || !bytes.HasPrefix(it.it.Key(), rawdb.SnapshotAccountPrefix) {
-		it.it.Release()
-		it.it = nil
-		return false
+	// Try to advance the iterator and release it if we reached the end
+	for {
+		if !it.it.Next() || !bytes.HasPrefix(it.it.Key(), rawdb.SnapshotAccountPrefix) {
+			it.it.Release()
+			it.it = nil
+			return false
+		}
+		if len(it.it.Key()) == len(rawdb.SnapshotAccountPrefix)+common.HashLength {
+			break
+		}
 	}
 	return true
 }

core/state/statedb.go

@@ -569,12 +569,19 @@ func (s *StateDB) GetOrNewStateObject(addr common.Address) *stateObject {
 func (s *StateDB) createObject(addr common.Address) (newobj, prev *stateObject) {
 	prev = s.getDeletedStateObject(addr) // Note, prev might have been deleted, we need that!
 
+	var prevdestruct bool
+	if s.snap != nil && prev != nil {
+		_, prevdestruct = s.snapDestructs[prev.addrHash]
+		if !prevdestruct {
+			s.snapDestructs[prev.addrHash] = struct{}{}
+		}
+	}
 	newobj = newObject(s, addr, Account{})
 	newobj.setNonce(0) // sets the object to dirty
 	if prev == nil {
 		s.journal.append(createObjectChange{account: &addr})
 	} else {
-		s.journal.append(resetObjectChange{prev: prev})
+		s.journal.append(resetObjectChange{prev: prev, prevdestruct: prevdestruct})
 	}
 	s.setStateObject(newobj)
 	return newobj, prev
@@ -595,9 +602,6 @@ func (s *StateDB) CreateAccount(addr common.Address) {
 	if prev != nil {
 		newObj.setBalance(prev.data.Balance)
 	}
-	if s.snap != nil && prev != nil {
-		s.snapDestructs[prev.addrHash] = struct{}{}
-	}
 }
 
 func (db *StateDB) ForEachStorage(addr common.Address, cb func(key, value common.Hash) bool) error {