trie: fix secureTrie copy

Author: jochem-brouwer

packages/trie/src/checkpointTrie.ts

@@ -16,7 +16,7 @@ export class CheckpointTrie extends BaseTrie {
    * Is the trie during a checkpoint phase?
    */
   get isCheckpoint() {
-    return this.db.checkpoints.length > 0
+    return this.db.isCheckpoint
   }
 
   /**

packages/trie/src/secure.ts

@@ -89,8 +89,11 @@ export class SecureTrie extends CheckpointTrie {
    * @param includeCheckpoints - If true and during a checkpoint, the copy will contain the checkpointing metadata and will use the same scratch as underlying db.
    */
   copy(includeCheckpoints = true): SecureTrie {
-    const trie = super.copy(includeCheckpoints)
-    const db = trie.db.copy()
-    return new SecureTrie(db._leveldb, this.root)
+    const db = this.db.copy()
+    const secureTrie = new SecureTrie(db._leveldb, this.root)
+    if (includeCheckpoints && this.isCheckpoint) {
+      secureTrie.db.checkpoints = this.db.checkpoints.slice()
+    }
+    return secureTrie
   }
 }