fix(ext/fetch): clone second branch chunks in Body.clone() (#20057)

This PR makes `Body.clone()` spec compliant:
https://fetch.spec.whatwg.org/#concept-body-clone

> 1, Let « out1, out2 » be the result of
[teeing](https://streams.spec.whatwg.org/#readablestream-tee) body’s
[stream](https://fetch.spec.whatwg.org/#concept-body-stream).
> ...
> To tee a
[ReadableStream](https://streams.spec.whatwg.org/#readablestream)
stream, return ?
[ReadableStreamTee](https://streams.spec.whatwg.org/#readable-stream-tee)(stream,
true).

---
Closes #10994

1 files changed, 2 insertions, 1 deletions

diff --git a/ext/fetch/22_body.js b/ext/fetch/22_body.js
index 9fe00b144..644b9f76f 100644
--- a/ext/fetch/22_body.js
+++ b/ext/fetch/22_body.js
@@ -33,6 +33,7 @@ import {
   readableStreamCollectIntoUint8Array,
   readableStreamDisturb,
   ReadableStreamPrototype,
+  readableStreamTee,
   readableStreamThrowIfErrored,
 } from "ext:deno_web/06_streams.js";
 const primordials = globalThis.__bootstrap.primordials;
@@ -194,7 +195,7 @@ class InnerBody {
    * @returns {InnerBody}
    */
   clone() {
-    const { 0: out1, 1: out2 } = this.stream.tee();
+    const { 0: out1, 1: out2 } = readableStreamTee(this.stream, true);
     this.streamOrStatic = out1;
     const second = new InnerBody(out2);
     second.source = core.deserialize(core.serialize(this.source));