From 750698cf45aa6509f333429d491603a3cd011d87 Mon Sep 17 00:00:00 2001
From: Neil <4138956+nwparker@users.noreply.github.com>
Date: Sat, 30 May 2026 04:20:05 -0700
Subject: [PATCH] Keep repo icon href probes inside repo

---
 src/main/repo-icon-autodetect.test.ts | 19 ++++++++++++++++++
 src/main/repo-icon-autodetect.ts      | 28 ++++++++++++++++++++++++++-
 2 files changed, 46 insertions(+), 1 deletion(-)

diff --git a/src/main/repo-icon-autodetect.test.ts b/src/main/repo-icon-autodetect.test.ts
index cfd5eb3f2c5..356fb48294c 100644
--- a/src/main/repo-icon-autodetect.test.ts
+++ b/src/main/repo-icon-autodetect.test.ts
@@ -69,6 +69,25 @@ describe('detectRepoIcon', () => {
     })
   })
 
+  it('does not resolve declared icon hrefs outside the repo', async () => {
+    const rootPath = await makeTempRepoDir()
+    const repoPath = join(rootPath, 'repo')
+    await mkdir(repoPath)
+    await writeFile(join(repoPath, 'index.html'), '<link rel="icon" href="../outside.png">')
+    await writeFile(join(rootPath, 'outside.png'), Buffer.from(PNG_1X1_BASE64, 'base64'))
+    await writeFile(
+      join(repoPath, 'package.json'),
+      JSON.stringify({ homepage: 'https://app.example.com/docs' })
+    )
+
+    await expect(detectRepoIcon({ repoPath, kind: 'folder' })).resolves.toEqual({
+      type: 'image',
+      src: 'https://www.google.com/s2/favicons?domain=app.example.com&sz=64',
+      source: 'favicon',
+      label: 'Website favicon'
+    })
+  })
+
   it('falls back to the GitHub owner avatar for GitHub repos', async () => {
     const repoPath = await makeTempRepoDir()
     await gitExecFileAsync(['init'], { cwd: repoPath })
diff --git a/src/main/repo-icon-autodetect.ts b/src/main/repo-icon-autodetect.ts
index 86ef07414d4..c5d6a1f50c9 100644
--- a/src/main/repo-icon-autodetect.ts
+++ b/src/main/repo-icon-autodetect.ts
@@ -75,9 +75,35 @@ function extractIconHref(source: string): string | null {
   return source.match(LINK_ICON_HTML_RE)?.[1] ?? source.match(LINK_ICON_OBJECT_RE)?.[1] ?? null
 }
 
+function normalizeIconRelativePath(relativePath: string): string | null {
+  const normalized = relativePath.replace(/\\/g, '/').trim()
+  if (
+    !normalized ||
+    normalized.startsWith('/') ||
+    normalized.includes('\0') ||
+    /^[A-Za-z][A-Za-z0-9+.-]*:/.test(normalized)
+  ) {
+    return null
+  }
+  const segments = normalized.split('/').filter((segment) => segment && segment !== '.')
+  if (segments.length === 0 || segments.some((segment) => segment === '..')) {
+    return null
+  }
+  return segments.join('/')
+}
+
 function iconHrefCandidates(href: string): string[] {
   const clean = href.replace(/^\/+/, '')
-  return [`public/${clean}`, clean]
+  const candidates: string[] = []
+  for (const candidate of [`public/${clean}`, clean]) {
+    // Why: icon hrefs are repo-controlled input; never let detection probe above
+    // the selected repo root while looking for a best-effort visual.
+    const normalized = normalizeIconRelativePath(candidate)
+    if (normalized && !candidates.includes(normalized)) {
+      candidates.push(normalized)
+    }
+  }
+  return candidates
 }
 
 async function readLocalPngIcon(repoPath: string, relativePath: string): Promise<RepoIcon | null> {