From e1d1d673fe0f8dc7a2cdbab8f3b188ad225c0f16 Mon Sep 17 00:00:00 2001
From: Bob Ippolito <bob@redivi.com>
Date: Fri, 27 Dec 2024 17:02:08 -0800
Subject: [PATCH 1/2] Failing test for #6974

---
 .../6974-delete-character-backward.spec.mjs   | 88 +++++++++++++++++++
 1 file changed, 88 insertions(+)
 create mode 100644 packages/lexical-playground/__tests__/regression/6974-delete-character-backward.spec.mjs

diff --git a/packages/lexical-playground/__tests__/regression/6974-delete-character-backward.spec.mjs b/packages/lexical-playground/__tests__/regression/6974-delete-character-backward.spec.mjs
new file mode 100644
index 00000000000..703596c8bb1
--- /dev/null
+++ b/packages/lexical-playground/__tests__/regression/6974-delete-character-backward.spec.mjs
@@ -0,0 +1,88 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ */
+
+import {
+  deleteBackward,
+  moveToLineBeginning,
+} from '../keyboardShortcuts/index.mjs';
+import {
+  assertHTML,
+  focusEditor,
+  html,
+  initialize,
+  test,
+} from '../utils/index.mjs';
+
+test.describe('Regression tests for #6974', () => {
+  test.beforeEach(({isPlainText, isCollab, page}) =>
+    initialize({isCollab, isPlainText, page}),
+  );
+
+  test(`deleteCharacter merges children from adjacent blocks even if the previous leaf is an inline decorator`, async ({
+    page,
+    isCollab,
+    isPlainText,
+  }) => {
+    test.skip(isCollab || isPlainText);
+    await focusEditor(page);
+    const testEquation = '$x$';
+    const testString = 'test';
+    await page.keyboard.type(testEquation);
+    await page.keyboard.press('Enter');
+    await page.keyboard.type(testString);
+    const beforeHtml = html`
+      <p>
+        <span contenteditable="false" data-lexical-decorator="true">
+          <img alt="" src="#" />
+          <span role="button" tabindex="-1">
+            <span>
+              <span aria-hidden="true">
+                <span>
+                  <span></span>
+                  <span>x</span>
+                </span>
+              </span>
+            </span>
+          </span>
+          <img alt="" src="#" />
+        </span>
+        <br />
+      </p>
+      <p dir="ltr"><span data-lexical-text="true">test</span></p>
+    `;
+    await assertHTML(page, beforeHtml, beforeHtml, {
+      ignoreClasses: true,
+      ignoreInlineStyles: true,
+    });
+    await moveToLineBeginning(page);
+    await deleteBackward(page);
+    const afterHtml = html`
+      <p dir="ltr">
+        <span contenteditable="false" data-lexical-decorator="true">
+          <img alt="" src="#" />
+          <span role="button" tabindex="-1">
+            <span>
+              <span aria-hidden="true">
+                <span>
+                  <span></span>
+                  <span>x</span>
+                </span>
+              </span>
+            </span>
+          </span>
+          <img alt="" src="#" />
+        </span>
+        <span data-lexical-text="true">test</span>
+      </p>
+    `;
+    await assertHTML(page, afterHtml, afterHtml, {
+      ignoreClasses: true,
+      ignoreInlineStyles: true,
+    });
+  });
+});

From c02e21716afe1e2b75c82de45c7854c6124d2de7 Mon Sep 17 00:00:00 2001
From: Bob Ippolito <bob@redivi.com>
Date: Mon, 30 Dec 2024 14:02:06 -0800
Subject: [PATCH 2/2] Fix getNodes() to not over-select the beginning

---
 packages/lexical/src/LexicalSelection.ts | 23 +++++++++++++++++++++--
 1 file changed, 21 insertions(+), 2 deletions(-)

diff --git a/packages/lexical/src/LexicalSelection.ts b/packages/lexical/src/LexicalSelection.ts
index 1de9a01ffaa..30c0c8f6a01 100644
--- a/packages/lexical/src/LexicalSelection.ts
+++ b/packages/lexical/src/LexicalSelection.ts
@@ -96,6 +96,14 @@ export class Point {
   _selection: BaseSelection | null;
 
   constructor(key: NodeKey, offset: number, type: 'text' | 'element') {
+    if (__DEV__) {
+      // This prevents a circular reference error when serialized as JSON,
+      // which happens on unit test failures
+      Object.defineProperty(this, '_selection', {
+        enumerable: false,
+        writable: true,
+      });
+    }
     this._selection = null;
     this.key = key;
     this.offset = offset;
@@ -473,6 +481,10 @@ export class RangeSelection implements BaseSelection {
     const lastPoint = isBefore ? focus : anchor;
     let firstNode = firstPoint.getNode();
     let lastNode = lastPoint.getNode();
+    const overselectedFirstNode =
+      $isElementNode(firstNode) &&
+      firstPoint.offset > 0 &&
+      firstPoint.offset >= firstNode.getChildrenSize();
     const startOffset = firstPoint.offset;
     const endOffset = lastPoint.offset;
 
@@ -506,6 +518,13 @@ export class RangeSelection implements BaseSelection {
       }
     } else {
       nodes = firstNode.getNodesBetween(lastNode);
+      // Prevent over-selection due to the edge case of getDescendantByIndex always returning something #6974
+      if (overselectedFirstNode) {
+        const deleteCount = nodes.findIndex(
+          (node) => !node.is(firstNode) && !node.isBefore(firstNode),
+        );
+        nodes.splice(0, deleteCount);
+      }
     }
     if (!isCurrentlyReadOnlyMode()) {
       this._cachedNodes = nodes;
@@ -1129,7 +1148,7 @@ export class RangeSelection implements BaseSelection {
       lastPoint.offset = lastNode.getTextContentSize();
     }
 
-    selectedNodes.forEach((node) => {
+    for (const node of selectedNodes) {
       if (
         !$hasAncestor(firstNode, node) &&
         !$hasAncestor(lastNode, node) &&
@@ -1138,7 +1157,7 @@ export class RangeSelection implements BaseSelection {
       ) {
         node.remove();
       }
-    });
+    }
 
     const fixText = (node: TextNode, del: number) => {
       if (node.getTextContent() === '') {