From e140193fa5f0e85a1d10825f81b9cbb763ad12c4 Mon Sep 17 00:00:00 2001
From: luin <i@zihua.li>
Date: Sat, 13 Jun 2020 13:51:26 +0800
Subject: [PATCH] Fix pasting in checklist does not preserve indentation

---
 modules/clipboard.js           |  2 +-
 test/unit/modules/clipboard.js | 14 ++++++++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/modules/clipboard.js b/modules/clipboard.js
index 0b870ae370..f8d409fe62 100644
--- a/modules/clipboard.js
+++ b/modules/clipboard.js
@@ -414,7 +414,7 @@ function matchIndent(node, delta, scroll) {
   }
   if (indent <= 0) return delta;
   return delta.reduce((composed, op) => {
-    if (op.attributes && op.attributes.list) {
+    if (op.attributes && typeof op.attributes.indent === 'number') {
       return composed.push(op);
     }
     return composed.insert(op.insert, { indent, ...(op.attributes || {}) });
diff --git a/test/unit/modules/clipboard.js b/test/unit/modules/clipboard.js
index 7ad5328be5..d542fc9fcd 100644
--- a/test/unit/modules/clipboard.js
+++ b/test/unit/modules/clipboard.js
@@ -203,6 +203,20 @@ describe('Clipboard', function() {
       );
     });
 
+    it('html nested checklist', function() {
+      const delta = this.clipboard.convert({
+        html:
+          '<ul><li data-list="checked">One<ul><li data-list="checked">Alpha</li><li data-list="checked">Beta' +
+          '<ul><li data-list="checked">I</li></ul></li></ul></li></ul>',
+      });
+      expect(delta).toEqual(
+        new Delta()
+          .insert('One\n', { list: 'checked' })
+          .insert('Alpha\nBeta\n', { list: 'checked', indent: 1 })
+          .insert('I\n', { list: 'checked', indent: 2 }),
+      );
+    });
+
     it('html partial list', function() {
       const delta = this.clipboard.convert({
         html: