From dca90c8024e3872f93d46c83891ac03e804fbda7 Mon Sep 17 00:00:00 2001
From: Vsevolod Kokorin <slonser@noreply.sheetjs.com>
Date: Wed, 12 Apr 2023 03:47:45 -0400
Subject: [PATCH] XLSX Ensure comment address is valid

---
 bits/56_cmntcommon.js | 1 +
 1 file changed, 1 insertion(+)

diff --git a/bits/56_cmntcommon.js b/bits/56_cmntcommon.js
index 76d0295..85e2186 100644
--- a/bits/56_cmntcommon.js
+++ b/bits/56_cmntcommon.js
@@ -3,6 +3,7 @@ function sheet_insert_comments(sheet/*:WorkSheet*/, comments/*:Array<RawComment>
 	var cell/*:Cell*/;
 	comments.forEach(function(comment) {
 		var r = decode_cell(comment.ref);
+		if(r.r < 0 || r.c < 0) return;
 		if(dense) {
 			if(!sheet["!data"][r.r]) sheet["!data"][r.r] = [];
 			cell = sheet["!data"][r.r][r.c];