fix: let keyless browser validation settle

changelog.d/1264-overpass-request-admission.md

@@ -1,3 +1,6 @@
 - Prevent malformed Overpass filters from blocking the local server, and reject
   cross-site or excessive query requests before reading their bodies
   (asturksever, #1264; fixes #1248).
+- Release unread responses from the optional Google-token probe so keyless
+  browser validation can settle; the Overpass gate recognizes only that probe's
+  expected 404 as an unavailable capability (asturksever, #1264).

docs/CURRENT-STATE.md

@@ -4557,6 +4557,12 @@ Retry-After; absent delays back off from 30 seconds to five minutes. Empty
 remain. Malformed capability-probe responses remain unknown and are retried after the existing 30-second backoff; valid configured decisions remain memoized.
 Consumer capability misses never schedule automatic retries.
 
+Keyless browser validation also probes the optional Google tiles-token route.
+The token client cancels rejected response bodies before returning unavailable,
+so they do not remain pending in browser network observation. The Overpass gate
+accepts only that same-origin route's expected 404 console diagnostic; other
+HTTP and JavaScript errors still fail acceptance.
+
 Operator-configured Overpass area and focus-footprint queries use body-level
 `out geom` (with `center` for focus), preserving relation member outlines.
 Member geometry is printed only inside a box around the point (6 km for

scripts/qa-overpass-offload.mjs

@@ -306,7 +306,16 @@ try {
   await observeNetwork(page);
   page.on('pageerror', (error) => result.errors.push(error.message));
   page.on('console', (message) => {
-    if (message.type() === 'error' && result.consoleErrors.length < 30)
+    if (message.type() !== 'error') return;
+    // A keyless server does not offer optional Google tokens. Keep every other
+    // HTTP or JavaScript error visible, including failures of this route other
+    // than its expected capability-miss 404.
+    const optionalTokenMiss =
+      message.location().url === new URL('/api/google/tiles-token', url).href &&
+      /^Failed to load resource: the server responded with a status of 404\b/.test(
+        message.text(),
+      );
+    if (!optionalTokenMiss && result.consoleErrors.length < 30)
       result.consoleErrors.push(message.text());
   });
   page.on('requestfailed', (request) => {

src/maps/googleTokens.js

@@ -38,7 +38,10 @@ export function createGoogleTokenSource({
         headers: { Accept: 'application/json' },
         cache: 'no-store',
       });
-      if (!response.ok) return null;
+      if (!response.ok) {
+        await response.body?.cancel();
+        return null;
+      }
       return parseToken(await response.json(), now());
     } catch {
       return null;

src/maps/googleTokens.test.mjs

@@ -50,6 +50,23 @@ test('requests refused for the same token renew it once', async () => {
   assert.equal(calls.length, 2);
 });
 
+test('a refused token response releases its unread body before returning', async () => {
+  for (const status of [404, 429, 500]) {
+    let cancelled = false;
+    const response = new Response(
+      new ReadableStream({
+        cancel() {
+          cancelled = true;
+        },
+      }),
+      { status },
+    );
+    const tokens = createGoogleTokenSource({ fetchImpl: async () => response });
+    assert.equal(await tokens.token(), null);
+    assert.equal(cancelled, true, `HTTP ${status} body released`);
+  }
+});
+
 test('a server that does not offer tokens yields none', async () => {
   for (const answer of [
     new Response('Not found', { status: 404 }),