From 1a932d62aa67cef9fcf6cee89caad3779eb04723 Mon Sep 17 00:00:00 2001
From: OrcaWin <alpha-eng@stably.ai>
Date: Thu, 22 Oct 2026 13:19:58 -0700
Subject: [PATCH] perf(markdown): scan wiki-link delimiters without revisiting
 the document tail (#31934)

Co-authored-by: OrcaWin <293788423+OrcaWin@users.noreply.github.com>
---
 .../components/editor/markdown-doc-links.ts   |  5 +++-
 .../raw-markdown-html.doc-link-scan.test.ts   | 27 +++++++++++++++++++
 .../components/editor/raw-markdown-html.ts    |  6 ++++-
 3 files changed, 36 insertions(+), 2 deletions(-)
 create mode 100644 src/renderer/src/components/editor/raw-markdown-html.doc-link-scan.test.ts

diff --git a/src/renderer/src/components/editor/markdown-doc-links.ts b/src/renderer/src/components/editor/markdown-doc-links.ts
index 3f5e4f7f6af..ca7f472ade1 100644
--- a/src/renderer/src/components/editor/markdown-doc-links.ts
+++ b/src/renderer/src/components/editor/markdown-doc-links.ts
@@ -152,12 +152,15 @@ export function resolveMarkdownDocLink(
 }
 
 export function parseMarkdownDocLink(rawTarget: string): ParsedMarkdownDocLink | null {
+  if (/[[\]]/.test(rawTarget)) {
+    return null
+  }
   const separatorIndex = rawTarget.indexOf('|')
   const target =
     separatorIndex === -1 ? rawTarget.trim() : rawTarget.slice(0, separatorIndex).trim()
   const alias = separatorIndex === -1 ? null : rawTarget.slice(separatorIndex + 1).trim() || null
 
-  if (!target || /[\r\n[\]]/.test(target) || (alias !== null && /[\r\n[\]]/.test(alias))) {
+  if (!target || /[\r\n]/.test(target) || (alias !== null && /[\r\n]/.test(alias))) {
     return null
   }
   if (separatorIndex !== -1 && alias === null) {
diff --git a/src/renderer/src/components/editor/raw-markdown-html.doc-link-scan.test.ts b/src/renderer/src/components/editor/raw-markdown-html.doc-link-scan.test.ts
new file mode 100644
index 00000000000..800e997cc16
--- /dev/null
+++ b/src/renderer/src/components/editor/raw-markdown-html.doc-link-scan.test.ts
@@ -0,0 +1,27 @@
+import { runInNewContext } from 'node:vm'
+import { expect, it } from 'vitest'
+import { encodeRawMarkdownHtmlForRichEditor } from './raw-markdown-html'
+import { createRichMarkdownEditorCodec } from './rich-markdown-source-transport'
+
+it.each([false, true])('encodes dense unfinished wiki links with a closing tail: %s', (closed) => {
+  const codec = createRichMarkdownEditorCodec('0'.repeat(32))
+  const prefix = '[[x '.repeat(400_000)
+  const content = closed ? `${prefix}]]\n[[valid]]` : prefix
+  const expected = closed
+    ? `${prefix.slice(0, -4)}${codec.transport.create('document-link', 'x')}\n${codec.transport.create('document-link', 'valid')}`
+    : prefix
+  const encoded = runInNewContext(
+    'encode(content, codec)',
+    { encode: encodeRawMarkdownHtmlForRichEditor, content, codec },
+    { timeout: 1500 }
+  )
+  expect(encoded).toBe(expected)
+})
+
+it('advances past literal and code delimiters while retaining trimmed link targets', () => {
+  const codec = createRichMarkdownEditorCodec('0'.repeat(32))
+  const content = ']] `[[code]]` [[bad [target]] [[\nfirst\n]] [[second|Label]] [[unfinished'
+  expect(encodeRawMarkdownHtmlForRichEditor(content, codec)).toBe(
+    `]] \`[[code]]\` [[bad [target]] ${codec.transport.create('document-link', 'first')} ${codec.transport.create('document-link', 'second|Label')} [[unfinished`
+  )
+})
diff --git a/src/renderer/src/components/editor/raw-markdown-html.ts b/src/renderer/src/components/editor/raw-markdown-html.ts
index 1c6c334b90b..d63a37b658c 100644
--- a/src/renderer/src/components/editor/raw-markdown-html.ts
+++ b/src/renderer/src/components/editor/raw-markdown-html.ts
@@ -49,6 +49,7 @@ export function encodeRawMarkdownHtmlForRichEditor(
   const lastCommentClose = normalizedContent.lastIndexOf('-->')
   const { transport } = codec
   let index = 0
+  let nextDocLinkClose = 0
   let activeFence: '`' | '~' | null = null
   let activeFenceLength = 0
   let result = ''
@@ -186,7 +187,10 @@ export function encodeRawMarkdownHtmlForRichEditor(
       normalizedContent[index + 1] === '[' &&
       !isEscaped(normalizedContent, index)
     ) {
-      const closingIndex = normalizedContent.indexOf(']]', index + 2)
+      if (nextDocLinkClose !== -1 && nextDocLinkClose < index + 2) {
+        nextDocLinkClose = normalizedContent.indexOf(']]', index + 2)
+      }
+      const closingIndex = nextDocLinkClose
       if (closingIndex !== -1) {
         const rawTarget = normalizedContent.slice(index + 2, closingIndex)
         const link = parseMarkdownDocLink(rawTarget)