mpt: fill cached fields when getting node from store

Node which has been got from store shouldn't be flushed again.

pkg/core/mpt/base.go

@@ -29,6 +29,18 @@ type BaseNodeIface interface {
 	SetFlushed()
 }
 
+type flushedNode interface {
+	setCache([]byte, util.Uint256)
+}
+
+func (b *BaseNode) setCache(bs []byte, h util.Uint256) {
+	b.bytes = bs
+	b.hash = h
+	b.bytesValid = true
+	b.hashValid = true
+	b.isFlushed = true
+}
+
 // getHash returns a hash of this BaseNode.
 func (b *BaseNode) getHash(n Node) util.Uint256 {
 	if !b.hashValid {

pkg/core/mpt/trie.go

@@ -354,6 +354,7 @@ func (t *Trie) getFromStore(h util.Uint256) (Node, error) {
 	if r.Err != nil {
 		return nil, r.Err
 	}
+	n.Node.(flushedNode).setCache(data, h)
 	return n.Node, nil
 }