From 2fc6d5d4dc3c41dc0d262e2ebdd8b6ab37ce1204 Mon Sep 17 00:00:00 2001
From: Jonathan Sykes <telemagnadon@gmail.com>
Date: Fri, 9 Oct 2026 10:43:05 +0800
Subject: [PATCH] Release response streams used by cache metadata probes

---
 frontend/asset-sync-core.js      | 17 +++++++++++++----
 frontend/asset-sync-core.test.js |  7 +++++++
 2 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/frontend/asset-sync-core.js b/frontend/asset-sync-core.js
index 1339fdb..9f34ce7 100644
--- a/frontend/asset-sync-core.js
+++ b/frontend/asset-sync-core.js
@@ -49,10 +49,19 @@
     return response ? response.json() : null;
   }
 
+  function verifiedProbe(response, hash) {
+    if (!response) return false;
+    const valid = response.headers.get('X-Asset-Hash') === hash;
+    // Metadata checks must release Blob/data-pipe readers. They never consume
+    // asset bytes, and cancelling this response does not remove its cache entry.
+    response.body?.cancel().catch(() => {});
+    return valid;
+  }
+
   async function status(manifest, cache, { previous, activeLayout, offline = true } = {}) {
     const found = await Promise.all(blocking(manifest, previous, activeLayout).map(async path => {
       const response = await cache.match(url(path, manifest.files[path]));
-      return !!response && response.headers.get('X-Asset-Hash') === manifest.files[path].h;
+      return verifiedProbe(response, manifest.files[path].h);
     }));
     const missing = found.filter(value => !value).length;
     return { ready: missing === 0, missing, version: manifest.buildTag, ...(offline ? await completeness(manifest, cache) : {}) };
@@ -85,7 +94,7 @@
     for (const path of selected) {
       const key = url(path, manifest.files[path]);
       const response = await cache.match(key);
-      if (!response || response.headers.get('X-Asset-Hash') !== manifest.files[path].h) missing.push(key);
+      if (!verifiedProbe(response, manifest.files[path].h)) missing.push(key);
     }
     const count = missing.length;
     let failure;
@@ -94,7 +103,7 @@
         const key = missing.shift();
         try { await sharedDownload(key, async () => {
         const held = await cache.match(key);
-        if (held?.headers.get('X-Asset-Hash') === key.split('v=')[1]) return;
+        if (verifiedProbe(held, key.split('v=')[1])) return;
         let error;
         for (let attempt = 0; attempt < Math.min(3, attempts); attempt++) {
           const controller = new AbortController();
@@ -127,7 +136,7 @@
     const files = paths(manifest);
     const missingFiles = (await Promise.all(files.map(async path => {
       const response = await cache.match(url(path, manifest.files[path]));
-      return !response || response.headers.get('X-Asset-Hash') !== manifest.files[path].h ? path : null;
+      return verifiedProbe(response, manifest.files[path].h) ? null : path;
     }))).filter(Boolean);
     const total = files.length;
     return { offlineReady: missingFiles.length === 0, cached: total - missingFiles.length, total, missingFiles };
diff --git a/frontend/asset-sync-core.test.js b/frontend/asset-sync-core.test.js
index 371864b..b5abdb6 100644
--- a/frontend/asset-sync-core.test.js
+++ b/frontend/asset-sync-core.test.js
@@ -89,3 +89,10 @@ test('blocking commit never waits on an optional file readiness probe',{timeout:
  await core.commit(m,c);assert.equal(extraProbes,0);assert.equal((await core.state(c)).current.buildTag,m.buildTag);
  c.match=match;assert.equal((await core.status(m,c)).offlineReady,false);
 });
+
+test('metadata probes release response streams while stored asset bodies remain readable',async()=>{
+ const c=cache(),m=manifest();await c.put('/a.js?v=a',response('a'));await c.put('/index.html?v=b',response('b'));
+ const match=c.match,probes=[];c.match=async key=>{const r=await match(key);if(r)probes.push(r);return r;};
+ assert.equal((await core.status(m,c)).offlineReady,true);assert.ok(probes.length>0);assert.ok(probes.every(r=>r.bodyUsed));
+ assert.equal(await(await match('/a.js?v=a')).text(),'a');assert.equal(await(await match('/index.html?v=b')).text(),'b');
+});