From c0ae61fa15dacfe3139c36acc21e16c4e36b668d Mon Sep 17 00:00:00 2001
From: Martin Holst Swende <martin@swende.se>
Date: Mon, 23 Oct 2023 18:34:21 +0200
Subject: [PATCH] trie: do error-checks prior to setting last/first in
 stacktrie

---
 trie/stacktrie.go | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/trie/stacktrie.go b/trie/stacktrie.go
index fd08898b58..42bd31acc6 100644
--- a/trie/stacktrie.go
+++ b/trie/stacktrie.go
@@ -98,21 +98,21 @@ func (t *StackTrie) Update(key, value []byte) error {
 	}
 	k := keybytesToHex(key)
 	k = k[:len(k)-1] // chop the termination flag
+	if bytes.Compare(t.last, k) >= 0 {
+		return errors.New("non-ascending key order")
+	}
+	if err := t.insert(t.root, k, value, nil); err != nil {
+		return err
+	}
 	// track the first and last inserted entries.
 	if t.first == nil {
 		t.first = append([]byte{}, k...)
 	}
-	if bytes.Compare(t.last, k) >= 0 {
-		return errors.New("non-ascending key order")
-	}
 	if t.last == nil {
 		t.last = append([]byte{}, k...) // allocate key slice
 	} else {
 		t.last = append(t.last[:0], k...) // reuse key slice
 	}
-	if err := t.insert(t.root, k, value, nil); err != nil {
-		return err
-	}
 	return nil
 }