cmd, core/state, eth, tests, trie: improve state reader (#27428)

The state availability is checked during the creation of a state reader.

-    In hash-based database, if the specified root node does not exist on disk disk, then
    the state reader won't be created and an error will be returned.

-    In path-based database, if the specified state layer is not available, then the
    state reader won't be created and an error will be returned.

This change also contains a stricter semantics regarding the `Commit` operation: once it has been performed, the trie is no longer usable, and certain operations will return an error.

cmd/evm/internal/t8ntool/execution.go

@@ -19,7 +19,6 @@ package t8ntool
 import (
 	"fmt"
 	"math/big"
-	"os"
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/math"
@@ -269,7 +268,6 @@ func (pre *Prestate) Apply(vmConfig vm.Config, chainConfig *params.ChainConfig,
 	// Commit block
 	root, err := statedb.Commit(chainConfig.IsEIP158(vmContext.BlockNumber))
 	if err != nil {
-		fmt.Fprintf(os.Stderr, "Could not commit state: %v", err)
 		return nil, nil, NewError(ErrorEVM, fmt.Errorf("could not commit state: %v", err))
 	}
 	execRs := &ExecutionResult{
@@ -288,6 +286,12 @@ func (pre *Prestate) Apply(vmConfig vm.Config, chainConfig *params.ChainConfig,
 		h := types.DeriveSha(types.Withdrawals(pre.Env.Withdrawals), trie.NewStackTrie(nil))
 		execRs.WithdrawalsRoot = &h
 	}
+	// Re-create statedb instance with new root upon the updated database
+	// for accessing latest states.
+	statedb, err = state.New(root, statedb.Database(), nil)
+	if err != nil {
+		return nil, nil, NewError(ErrorEVM, fmt.Errorf("could not reopen state: %v", err))
+	}
 	return statedb, execRs, nil
 }