core/state: copy the snap when copying the state (ethereum#22340)

* core/state: copy the snap when copying the state

* core/state: deep-copy snap stuff during state Copy

core/state/statedb.go

@@ -728,6 +728,31 @@ func (s *StateDB) Copy() *StateDB {
 	if s.prefetcher != nil {
 		state.prefetcher = s.prefetcher.copy()
 	}
+	if s.snaps != nil {
+		// In order for the miner to be able to use and make additions
+		// to the snapshot tree, we need to copy that aswell.
+		// Otherwise, any block mined by ourselves will cause gaps in the tree,
+		// and force the miner to operate trie-backed only
+		state.snaps = s.snaps
+		state.snap = s.snap
+		// deep copy needed
+		state.snapDestructs = make(map[common.Hash]struct{})
+		for k, v := range s.snapDestructs {
+			state.snapDestructs[k] = v
+		}
+		state.snapAccounts = make(map[common.Hash][]byte)
+		for k, v := range s.snapAccounts {
+			state.snapAccounts[k] = v
+		}
+		state.snapStorage = make(map[common.Hash]map[common.Hash][]byte)
+		for k, v := range s.snapStorage {
+			temp := make(map[common.Hash][]byte)
+			for kk, vv := range v {
+				temp[kk] = vv
+			}
+			state.snapStorage[k] = temp
+		}
+	}
 	return state
 }