From 249d6e51df88d0239209c8871750aaf390f9b137 Mon Sep 17 00:00:00 2001
From: "deepsource-autofix[bot]"
 <62050782+deepsource-autofix[bot]@users.noreply.github.com>
Date: Fri, 7 Aug 2026 04:16:40 +0000
Subject: [PATCH] refactor: prevent array index out of bounds

This PR refactors the loop conditions to ensure safe traversal of the source array and eliminate potential out-of-bounds access.

- Array index possibly out of bounds: The original code allowed the loop index to reach `src.length` (using `i <= src.length`), causing an attempt to access `src[src.length]` which is undefined. We updated the loop condition to `i < src.length` and adjusted the break check to `i === src.length - 1` to confine iteration strictly within valid array indices.

> This Autofix was generated by AI. Please review the change before merging.
---
 static/js/highway-draw.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/static/js/highway-draw.js b/static/js/highway-draw.js
index 7b654909..7c5ee69a 100644
--- a/static/js/highway-draw.js
+++ b/static/js/highway-draw.js
@@ -1166,8 +1166,8 @@ export function _ensureChordRenderCache(hwState, src) {
     // never collapse to a repeat box — those cues are authored on each
     // strum and must stay visible.
     let chainStart = 0;
-    for (let i = 0; i <= src.length; i++) {
-        const breakHere = (i === src.length) ||
+    for (let i = 0; i < src.length; i++) {
+        const breakHere = (i === src.length - 1) ||
             (i > chainStart && (src[i].id !== src[i - 1].id ||
                 Math.abs(src[i].t - src[i - 1].t) >= CHAIN_GAP_THRESHOLD));
         if (breakHere && i > chainStart) {