fix(ext/fetch) Fix request clone error in flash server (#16174)

cli/tests/unit/flash_test.ts

@@ -2328,6 +2328,45 @@ Deno.test(
   },
 );
 
+// https://github.com/denoland/deno/issues/15858
+Deno.test(
+  { permissions: { net: true } },
+  async function httpServerCanCloneRequest() {
+    const ac = new AbortController();
+    const listeningPromise = deferred();
+
+    const server = Deno.serve({
+      handler: async (req) => {
+        const cloned = req.clone();
+        assertEquals(req.headers, cloned.headers);
+
+        // both requests can read body
+        await req.text();
+        await cloned.json();
+
+        return new Response("ok");
+      },
+      signal: ac.signal,
+      onListen: onListen(listeningPromise),
+      onError: createOnErrorCb(ac),
+    });
+
+    try {
+      await listeningPromise;
+      const resp = await fetch("http://localhost:9000/", {
+        headers: { connection: "close" },
+        method: "POST",
+        body: '{"sus":true}',
+      });
+      const text = await resp.text();
+      assertEquals(text, "ok");
+    } finally {
+      ac.abort();
+      await server;
+    }
+  },
+);
+
 // Checks large streaming response
 // https://github.com/denoland/deno/issues/16567
 Deno.test(

ext/fetch/23_request.js

@@ -155,9 +155,11 @@
   /**
    * https://fetch.spec.whatwg.org/#concept-request-clone
    * @param {InnerRequest} request
+   * @param {boolean} skipBody
+   * @param {boolean} flash
    * @returns {InnerRequest}
    */
-  function cloneInnerRequest(request, skipBody = false) {
+  function cloneInnerRequest(request, skipBody = false, flash = false) {
     const headerList = ArrayPrototypeMap(
       request.headerList,
       (x) => [x[0], x[1]],
@@ -168,6 +170,19 @@
       body = request.body.clone();
     }
 
+    if (flash) {
+      return {
+        body,
+        methodCb: request.methodCb,
+        urlCb: request.urlCb,
+        headerList: request.headerList,
+        streamRid: request.streamRid,
+        serverId: request.serverId,
+        redirectMode: "follow",
+        redirectCount: 0,
+      };
+    }
+
     return {
       method: request.method,
       headerList,
@@ -487,16 +502,30 @@
       }
       let newReq;
       if (this[_flash]) {
-        newReq = cloneInnerRequest(this[_flash]);
+        newReq = cloneInnerRequest(this[_flash], false, true);
       } else {
         newReq = cloneInnerRequest(this[_request]);
       }
       const newSignal = abortSignal.newSignal();
-      abortSignal.follow(newSignal, this[_signal]);
+
+      if (this[_signal]) {
+        abortSignal.follow(newSignal, this[_signal]);
+      }
+
+      if (this[_flash]) {
+        return fromInnerRequest(
+          newReq,
+          newSignal,
+          guardFromHeaders(this[_headers]),
+          true,
+        );
+      }
+
       return fromInnerRequest(
         newReq,
         newSignal,
         guardFromHeaders(this[_headers]),
+        false,
       );
     }
 
@@ -573,14 +602,22 @@
 
   /**
    * @param {InnerRequest} inner
+   * @param {AbortSignal} signal
    * @param {"request" | "immutable" | "request-no-cors" | "response" | "none"} guard
+   * @param {boolean} flash
    * @returns {Request}
    */
-  function fromInnerRequest(inner, signal, guard) {
+  function fromInnerRequest(inner, signal, guard, flash) {
     const request = webidl.createBranded(Request);
-    request[_request] = inner;
+    if (flash) {
+      request[_flash] = inner;
+    } else {
+      request[_request] = inner;
+    }
     request[_signal] = signal;
-    request[_getHeaders] = () => headersFromHeaderList(inner.headerList, guard);
+    request[_getHeaders] = flash
+      ? () => headersFromHeaderList(inner.headerList(), guard)
+      : () => headersFromHeaderList(inner.headerList, guard);
     return request;
   }
 
@@ -606,6 +643,7 @@
       body: body !== null ? new InnerBody(body) : null,
       methodCb,
       urlCb,
+      headerList: headersCb,
       streamRid,
       serverId,
       redirectMode: "follow",

ext/fetch/internal.d.ts

@@ -83,6 +83,8 @@ declare namespace globalThis {
           | "request-no-cors"
           | "response"
           | "none",
+        skipBody: boolean,
+        flash: boolean,
       ): Request;
       function redirectStatus(status: number): boolean;
       function nullBodyStatus(status: number): boolean;

ext/http/01_http.js

@@ -135,7 +135,12 @@
         false,
       );
       const signal = abortSignal.newSignal();
-      const request = fromInnerRequest(innerRequest, signal, "immutable");
+      const request = fromInnerRequest(
+        innerRequest,
+        signal,
+        "immutable",
+        false,
+      );
 
       const respondWith = createRespondWith(
         this,