From 7405f5dc4bb8aa629bf97b00dc5dae1ea50d355e Mon Sep 17 00:00:00 2001
From: Neil <4138956+nwparker@users.noreply.github.com>
Date: Sat, 30 May 2026 06:27:43 -0700
Subject: [PATCH] fix: ignore malformed markdown file links (#3695)

---
 .../editor/markdown-internal-links.test.ts           |  4 ++++
 .../src/components/editor/markdown-internal-links.ts | 12 ++++++++++--
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/src/renderer/src/components/editor/markdown-internal-links.test.ts b/src/renderer/src/components/editor/markdown-internal-links.test.ts
index 95e8e6407f5..8d624c1430f 100644
--- a/src/renderer/src/components/editor/markdown-internal-links.test.ts
+++ b/src/renderer/src/components/editor/markdown-internal-links.test.ts
@@ -123,6 +123,10 @@ describe('resolveMarkdownLinkTarget', () => {
     })
   })
 
+  it('returns null for malformed percent-encoded file URL paths', () => {
+    expect(resolveMarkdownLinkTarget('file:///repo/docs/%zz.md', SOURCE, ROOT)).toBeNull()
+  })
+
   it('returns null for empty href', () => {
     expect(resolveMarkdownLinkTarget('', SOURCE, ROOT)).toBeNull()
     expect(resolveMarkdownLinkTarget(undefined, SOURCE, ROOT)).toBeNull()
diff --git a/src/renderer/src/components/editor/markdown-internal-links.ts b/src/renderer/src/components/editor/markdown-internal-links.ts
index deac13b4c50..09694c86942 100644
--- a/src/renderer/src/components/editor/markdown-internal-links.ts
+++ b/src/renderer/src/components/editor/markdown-internal-links.ts
@@ -51,8 +51,13 @@ function toFileUrl(filePath: string): string {
   return `file:///${segments.join('/')}`
 }
 
-function fileUrlToAbsolutePath(url: URL): string {
-  let absolutePath = decodeURIComponent(url.pathname)
+function fileUrlToAbsolutePath(url: URL): string | null {
+  let absolutePath: string
+  try {
+    absolutePath = decodeURIComponent(url.pathname)
+  } catch {
+    return null
+  }
   // Windows: "/C:/foo" → "C:/foo"
   if (/^\/[A-Za-z]:\//.test(absolutePath)) {
     absolutePath = absolutePath.slice(1)
@@ -175,6 +180,9 @@ export function resolveMarkdownLinkTarget(
   }
 
   const rawAbsolutePath = fileUrlToAbsolutePath(resolved)
+  if (rawAbsolutePath === null) {
+    return null
+  }
 
   // Why: hash-based line anchor takes precedence; fall back to trailing
   // `:line:col` syntax only if no hash anchor was found.