From 1c201b077212c72f9ae03f5fb2409815dae15264 Mon Sep 17 00:00:00 2001
From: Linus Rath <139418639+rathlinus@users.noreply.github.com>
Date: Wed, 4 Nov 2026 03:04:12 +0100
Subject: [PATCH] fix: stop private files with odd casing and links reaching
 Docker builds

---
 lib/__tests__/standalone-guard.test.ts | 32 +++++++++++++++++++++++++-
 scripts/standalone-guard.mjs           |  9 +++++---
 2 files changed, 37 insertions(+), 4 deletions(-)

diff --git a/lib/__tests__/standalone-guard.test.ts b/lib/__tests__/standalone-guard.test.ts
index 347d8f526..32965e957 100644
--- a/lib/__tests__/standalone-guard.test.ts
+++ b/lib/__tests__/standalone-guard.test.ts
@@ -1,6 +1,6 @@
 // @vitest-environment node
 import { afterEach, describe, expect, it } from 'vitest';
-import { existsSync, mkdirSync, mkdtempSync, readFileSync, rmSync, writeFileSync } from 'node:fs';
+import { existsSync, mkdirSync, mkdtempSync, readFileSync, rmSync, symlinkSync, writeFileSync } from 'node:fs';
 import { spawnSync } from 'node:child_process';
 import os from 'node:os';
 import path from 'node:path';
@@ -120,6 +120,36 @@ describe('standalone guard check', () => {
     expect(findForbidden(dir)).toEqual(['worktrees/webmail/data/']);
   });
 
+  it('goes by the name in any case, as a case-insensitive disk and Docker context would', () => {
+    const dir = tempDir();
+    put(dir, 'server.js');
+    put(dir, '.ENV', 'SECRET=1');
+    put(dir, 'Plugin-Signing.KEY', 'SECRET=1');
+    put(dir, 'Data/admin.json');
+    put(dir, 'LOCAL-DATA/a');
+    put(dir, 'Repos/a');
+    expect(findForbidden(dir)).toEqual(['.ENV', 'Data/', 'LOCAL-DATA/', 'Plugin-Signing.KEY', 'Repos/']);
+  });
+
+  it('refuses a link: it would ship whatever it points at', () => {
+    const dir = tempDir();
+    const outside = tempDir();
+    put(outside, 'admin.json');
+    put(dir, 'server.js');
+    symlinkSync(outside, path.join(dir, 'state'), 'junction');
+    expect(findForbidden(dir)).toEqual(['state (link)']);
+  });
+
+  it('leaves the links of .next and node_modules alone: Turbopack makes those on purpose', () => {
+    const dir = tempDir();
+    const outside = tempDir();
+    put(dir, 'node_modules/a/index.js');
+    mkdirSync(path.join(dir, '.next', 'node_modules'), { recursive: true });
+    symlinkSync(path.join(dir, 'node_modules', 'a'), path.join(dir, '.next', 'node_modules', 'a-1234'), 'junction');
+    symlinkSync(outside, path.join(dir, 'node_modules', 'b'), 'junction');
+    expect(findForbidden(dir)).toEqual([]);
+  });
+
   it('removes the .env files Next copies next to server.js, then passes', () => {
     const dir = tempDir();
     put(dir, 'worktrees/webmail/server.js');
diff --git a/scripts/standalone-guard.mjs b/scripts/standalone-guard.mjs
index 192cc94e8..80a268e1d 100644
--- a/scripts/standalone-guard.mjs
+++ b/scripts/standalone-guard.mjs
@@ -25,7 +25,7 @@ const TRACE_ALLOWED = new Set(['node_modules', '.next', 'public', 'locales', 'pa
 
 /** Never in a standalone tree, wherever it sits outside node_modules. */
 const FORBIDDEN_DIRS = new Set(['data', 'local-data', 'repos']);
-const FORBIDDEN_FILE = /^(\.env.*|plugin-signing\.key)$/;
+const FORBIDDEN_FILE = /^(\.env.*|plugin-signing\.key)$/i;
 
 function toPosix(p) {
   return p.split(path.sep).join('/');
@@ -106,10 +106,13 @@ export function findForbidden(standaloneDir) {
   const visit = (dir) => {
     for (const entry of readdirSync(dir, { withFileTypes: true })) {
       const full = path.join(dir, entry.name);
-      if (entry.isDirectory()) {
+      if (entry.isSymbolicLink()) {
+        // Not .next's or a package's, which aren't visited: Turbopack links those on purpose.
+        if (entry.name !== 'node_modules' && entry.name !== '.next') found.push(`${toPosix(path.relative(standaloneDir, full))} (link)`);
+      } else if (entry.isDirectory()) {
         // Packages may hold anything, and .next/server has routes named after data.
         if (entry.name === 'node_modules' || entry.name === '.next') continue;
-        if (FORBIDDEN_DIRS.has(entry.name)) found.push(toPosix(path.relative(standaloneDir, full)) + '/');
+        if (FORBIDDEN_DIRS.has(entry.name.toLowerCase())) found.push(toPosix(path.relative(standaloneDir, full)) + '/');
         else visit(full);
       } else if (FORBIDDEN_FILE.test(entry.name)) {
         found.push(toPosix(path.relative(standaloneDir, full)));