From 42479b313cc43e24c4fc6b84cac2db24cf797338 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Gerg=C5=91=20T=C3=B6rcsv=C3=A1ri?=
 <torcsvari.gergo@gmail.com>
Date: Mon, 17 Aug 2026 12:32:15 +0200
Subject: [PATCH] fix(cdn): stop stamping range-less GETs as 206 partial
 responses
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env.BUCKET.get(key, { range: request.headers }) makes R2 report a
DEFINED object.range (full span) even when the request carried no Range
header, so every plain GET went out as 206 + Content-Range. Chrome
executes a 206 <script>; Firefox fires onload but refuses to EXECUTE
the script — on hosts with no masking edge cache (staging workers.dev)
the injected editor glue never ran: no [KICAD_STATUS] logs, heap 0MB,
'runtime did not initialize (no FS) in 90s' on every Firefox boot.
Prod's cdn.pcbjam.com zone cache normalizes cached hits to 200, which
is why only staging surfaced it; cold prod objects share the bug.

Pass the range option only when the request actually sent a Range.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PmR6goSk7JC17h7fkgGvHG
---
 workers/cdn/src/index.ts | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/workers/cdn/src/index.ts b/workers/cdn/src/index.ts
index 71e7ef2..ffd2577 100644
--- a/workers/cdn/src/index.ts
+++ b/workers/cdn/src/index.ts
@@ -41,9 +41,17 @@ export default {
       );
     }
 
-    const object = await env.BUCKET.get(key, {
-      range: request.headers,
-    });
+    // Only ask R2 for a range when the request actually sent one: passing the
+    // headers unconditionally makes R2 report a DEFINED object.range (full
+    // span) even for range-less GETs, which stamped EVERY response 206 +
+    // Content-Range. Chrome shrugs at a 206 <script>; Firefox fires onload but
+    // refuses to EXECUTE it, so on hosts with no masking edge cache (staging's
+    // workers.dev) the editor glue never ran — "runtime did not initialize
+    // (no FS) in 90s" on every Firefox boot.
+    const object = await env.BUCKET.get(
+      key,
+      request.headers.has("Range") ? { range: request.headers } : {},
+    );
     if (!object) {
       return new Response("Not Found", { status: 404, headers: baseHeaders() });
     }