CORS write-off only on a refusal corsFetch confirmed, not a body cut off mid-download

Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_011bvzKaZosXGHkigcGcSzAR

1 files changed, 6 insertions, 6 deletions

diff --git a/src/features/messages.js b/src/features/messages.js
index a517407..c1e39d7 100644
--- a/src/features/messages.js
+++ b/src/features/messages.js
@@ -727,7 +727,7 @@ export function messagesFeature(ctx) {
   // is left alone for a week rather than asked about every new face.
   // v2: the first list was mostly wrong (primal's CDN, coinos.io) — see corsFetch
   // v3: v2 also caught dropped connections (primal again, on a phone)
-  const NOCORS_KEY = 'coinos-thumb-nocors-v3';
+  const NOCORS_KEY = 'coinos-thumb-nocors-v4';
   const NOCORS_MS = 7 * 24 * 3600_000;
   let noCors = null; // host -> { n, until }
   const noCorsNow = () => { if (!noCors) { try { noCors = JSON.parse(localStorage.getItem(NOCORS_KEY) || '{}'); } catch { noCors = {}; } } return noCors; };
@@ -764,7 +764,7 @@ export function messagesFeature(ctx) {
         if (!e2 || e2.name !== 'TypeError') throw e2;
         let reachable = false;
         try { await fetch(url, { mode: 'no-cors', signal }); reachable = true; } catch {}
-        if (reachable) throw e2;
+        if (reachable) { e2.corsRefused = true; throw e2; }
         const net = new Error('network'); net.name = 'NetworkError';
         throw net;
       }
@@ -844,7 +844,9 @@ export function messagesFeature(ctx) {
         done({ thumb: data, thumbFor: url, thumbPx: THUMB_PX });
       } catch (e) {
         // a quick TypeError is the CORS refusal (a dead host takes longer)
-        if (e && e.name === 'TypeError' && Date.now() - t0 < 4000) noteNoCors(url);
+        // only a refusal corsFetch confirmed (a body cut off mid-download
+        // is a TypeError too)
+        if (e && e.corsRefused) noteNoCors(url);
         failed();
       } finally { try { bmp && bmp.close(); } catch {} }
     })();
@@ -5384,15 +5386,13 @@ export function messagesFeature(ctx) {
   }
   async function makeMediaThumb(url) {
     if (noCorsHost(url) || typeof createImageBitmap === 'undefined' || typeof OffscreenCanvas === 'undefined') return null;
-    const t0 = Date.now();
     let blob;
     try {
       const res = await corsFetch(url, AbortSignal.timeout(READY_MS));
       if (!res.ok) return null;
       blob = await res.blob();
     } catch (e) {
-      // a quick TypeError is the CORS refusal (a dead host takes longer)
-      if (e && e.name === 'TypeError' && Date.now() - t0 < 4000) noteNoCors(url);
+      if (e && e.corsRefused) noteNoCors(url); // refused, as corsFetch confirmed
       return null;
     }
     let bmp;