From 2c6be72f35f68513b0d511a37037018663cbc704 Mon Sep 17 00:00:00 2001
From: Yanzhen Yu <yanzhen@smartx.com>
Date: Sat, 27 Feb 2021 13:46:29 +0800
Subject: [PATCH] close #491 check whether link node is head

---
 src/record/mutation.ts | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/record/mutation.ts b/src/record/mutation.ts
index bcdf7591..d80fb299 100644
--- a/src/record/mutation.ts
+++ b/src/record/mutation.ts
@@ -62,7 +62,11 @@ class DoubleLinkedList {
       if (current) {
         current.previous = node;
       }
-    } else if (n.nextSibling && isNodeInLinkedList(n.nextSibling)) {
+    } else if (
+      n.nextSibling &&
+      isNodeInLinkedList(n.nextSibling) &&
+      n.nextSibling.__ln.previous
+    ) {
       const current = n.nextSibling.__ln.previous;
       node.previous = current;
       node.next = n.nextSibling.__ln;