From bb446c717f92ef912f5000ddc757b9d1071120dc Mon Sep 17 00:00:00 2001
From: Jonathan Sykes <telemagnadon@gmail.com>
Date: Wed, 7 Oct 2026 23:58:29 +0800
Subject: [PATCH] Keep single-tag rollback on the legacy worker path

---
 server/asset-manifest.js      | 2 ++
 server/asset-manifest.test.js | 4 ++++
 2 files changed, 6 insertions(+)

diff --git a/server/asset-manifest.js b/server/asset-manifest.js
index 22e4384..6df5494 100644
--- a/server/asset-manifest.js
+++ b/server/asset-manifest.js
@@ -27,6 +27,8 @@ export function stampIndex(source, files, { hashing = true, buildTag = '__BUILD_
 }
 
 export function createAssetManifest(publicDir = './public', { hashing = true, buildTag: override, assetSync = true } = {}) {
+  // Single-tag URLs cannot be verified against per-file URL hashes.
+  assetSync = hashing && assetSync;
   const bytes = new Map();
   const legacy = createHash('sha256');
   function walk(dir, prefix = '') {
diff --git a/server/asset-manifest.test.js b/server/asset-manifest.test.js
index 0b03375..c09a7a3 100644
--- a/server/asset-manifest.test.js
+++ b/server/asset-manifest.test.js
@@ -68,3 +68,7 @@ test('sync rollback changes build identity and injected worker byte hash', () =>
   expect(on.manifest.buildTag).not.toBe(off.manifest.buildTag);
   expect(off.manifest.files['/sw.js'].h).toBe(hash(off.sw));
 }));
+test('single-tag hashing rollback also selects the legacy worker', () => fixture(dir => {
+  writeFileSync(join(dir,'sw.js'), "const VERSION = typeof __BUILD_TAG__ !== 'undefined' ? __BUILD_TAG__ : 'old'; const SYNC = typeof __ASSET_SYNC__ !== 'undefined' ? __ASSET_SYNC__ : true;");
+  expect(createAssetManifest(dir,{hashing:false}).sw).toContain('const SYNC = false');
+}));