From 5e21b361ef5974bf87aaa9e99309d373ddf4713f Mon Sep 17 00:00:00 2001
From: tbro <tbro@users.noreply.github.com>
Date: Thu, 19 Dec 2024 09:13:18 -0300
Subject: [PATCH] Do a checked_sub instead.

I put the integer being subtracted from in the error to distinguish
from rust panic message.
---
 sequencer/src/api/sql.rs | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/sequencer/src/api/sql.rs b/sequencer/src/api/sql.rs
index c265f8974..359a3e260 100644
--- a/sequencer/src/api/sql.rs
+++ b/sequencer/src/api/sql.rs
@@ -208,7 +208,9 @@ async fn load_frontier<Mode: TransactionMode>(
 ) -> anyhow::Result<BlocksFrontier> {
     tx.get_path(
         Snapshot::<SeqTypes, BlockMerkleTree, { BlockMerkleTree::ARITY }>::Index(height),
-        height - 1,
+        height
+            .checked_sub(1)
+            .ok_or(anyhow::anyhow!("Subtract with overflow ({height})!"))?,
     )
     .await
     .context(format!("fetching frontier at height {height}"))