From cf101f681158a48b1b477c1544680cc9614425ae Mon Sep 17 00:00:00 2001
From: Jason Chen <jhchen7@gmail.com>
Date: Mon, 16 Aug 2021 17:57:22 -0700
Subject: [PATCH] track all implicit newline indexes and shift for delete

---
 core/editor.js | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/core/editor.js b/core/editor.js
index 414bd81a7a..5d1dfafc9f 100644
--- a/core/editor.js
+++ b/core/editor.js
@@ -18,10 +18,12 @@ class Editor {
   }
 
   applyDelta(delta) {
-    let consumeNextNewline = false;
     this.scroll.update();
     let scrollLength = this.scroll.length();
     this.scroll.batchStart();
+    // Track indexes of violations of newline requirements
+    // (at end of doc and before block embeds)
+    const implicitNewlines = [];
     const normalizedDelta = normalizeDelta(delta);
     normalizedDelta.reduce((index, op) => {
       const length = Op.length(op);
@@ -29,8 +31,8 @@ class Editor {
       if (op.insert != null) {
         if (typeof op.insert === 'string') {
           let text = op.insert;
-          if (text.endsWith('\n') && consumeNextNewline) {
-            consumeNextNewline = false;
+          if (text.endsWith('\n') && implicitNewlines.length > 0) {
+            implicitNewlines.shift();
             text = text.slice(0, -1);
           }
           if (
@@ -38,7 +40,7 @@ class Editor {
               this.scroll.descendant(BlockEmbed, index)[0]) &&
             !text.endsWith('\n')
           ) {
-            consumeNextNewline = true;
+            implicitNewlines.push(index + length);
           }
           this.scroll.insertAt(index, text);
           const [line, offset] = this.scroll.line(index);
@@ -55,7 +57,7 @@ class Editor {
             this.scroll.query(key, Scope.INLINE) != null &&
             this.scroll.descendant(BlockEmbed, index)[0]
           ) {
-            consumeNextNewline = true;
+            implicitNewlines.push(index);
           }
           this.scroll.insertAt(index, key, op.insert[key]);
         }
@@ -66,7 +68,10 @@ class Editor {
       });
       return index + length;
     }, 0);
-    normalizedDelta.reduce((index, op) => {
+    const implicitDelta = implicitNewlines.reduce((delta, index) => {
+      return delta.retain(index).delete(1);
+    }, new Delta());
+    normalizedDelta.compose(implicitDelta).reduce((index, op) => {
       if (typeof op.delete === 'number') {
         this.scroll.deleteAt(index, op.delete);
         return index;