fix: ensure post values are added to a VerkleTrie during conversion

Signed-off-by: Guillaume Ballet <[email protected]>

consensus/beacon/consensus.go

@@ -421,7 +421,7 @@ func (beacon *Beacon) FinalizeAndAssemble(chain consensus.ChainHeaderReader, hea
 	// Assemble and return the final block.
 	block := types.NewBlockWithWithdrawals(header, txs, uncles, receipts, withdrawals, trie.NewStackTrie(nil))
 	if chain.Config().IsVerkle(header.Number, header.Time) && chain.Config().ProofInBlocks {
-		err := trie.AddPostValuesToProof(state.GetTrie().(*trie.VerkleTrie), proof)
+		err := trie.AddPostValuesToProof(getVerkleTrieOrEmpty(state.GetTrie(), state.Database().TrieDB()), proof)
 		if err != nil {
 			return nil, fmt.Errorf("error adding post values to proof: %w", err)
 		}
@@ -434,18 +434,9 @@ func (beacon *Beacon) FinalizeAndAssemble(chain consensus.ChainHeaderReader, hea
 	return block, nil
 }
 
-func BuildVerkleProof(header *types.Header, state *state.StateDB, parentRoot common.Hash, keys [][]byte) (*verkle.Proof, error) {
-	var (
-		proof *verkle.Proof
-	)
-
-	preTrie, err := state.Database().OpenTrie(parentRoot)
-	if err != nil {
-		return nil, fmt.Errorf("error opening pre-state tree root: %w", err)
-	}
-
+func getVerkleTrieOrEmpty(tr state.Trie, triedb *trie.Database) *trie.VerkleTrie {
 	var vtr *trie.VerkleTrie
-	switch pre := preTrie.(type) {
+	switch pre := tr.(type) {
 	case *trie.VerkleTrie:
 		vtr = pre
 	case *trie.TransitionTrie:
@@ -454,9 +445,23 @@ func BuildVerkleProof(header *types.Header, state *state.StateDB, parentRoot com
 		// This should only happen for the first block of the
 		// conversion, when the previous tree is a merkle tree.
 		//  Logically, the "previous" verkle tree is an empty tree.
-		vtr = trie.NewVerkleTrie(verkle.New(), state.Database().TrieDB(), utils.NewPointCache(), false)
+		vtr = trie.NewVerkleTrie(verkle.New(), triedb, utils.NewPointCache(), false)
+	}
+	return vtr
+}
+
+func BuildVerkleProof(header *types.Header, state *state.StateDB, parentRoot common.Hash, keys [][]byte) (*verkle.Proof, error) {
+	var (
+		proof *verkle.Proof
+	)
+
+	preTrie, err := state.Database().OpenTrie(parentRoot)
+	if err != nil {
+		return nil, fmt.Errorf("error opening pre-state tree root: %w", err)
 	}
+
 	if len(keys) > 0 {
+		vtr := getVerkleTrieOrEmpty(preTrie, state.Database().TrieDB())
 		proof, err = trie.Proof(vtr, nil, keys, vtr.FlatdbNodeResolver)
 		if err != nil {
 			return nil, fmt.Errorf("error generating verkle proof for block %d: %w", header.Number, err)