Responding with boxed strings breaks HTTP server

[Mabi19]

Version: Deno 1.46.0 and 1.46.1 (does not happen on 1.45.5 and below)
OS: Windows 11 / Linux (Debian 12)

Returning a Response made with a boxed string in the Deno.serve callback results in multiple calls to the handler per request and no data actually being sent, resulting in a "connection reset" / "empty response" error on the client-side.

Deno.serve(() => new Response(new String("uh oh!") as string));

Boxed strings are occasionally sent by Hono apps, like this one:

// assuming import map entry for "hono" exists
import { Hono } from "hono";
import { html } from "hono/html";

const app = new Hono();

app.get("/", (ctx) => {
    console.log("this will be logged multiple times!");
    return ctx.html(
        Promise.resolve(html`<div></div>`),
    );
});

Deno.serve(app.fetch);

[lucacasonato]

Caused by ba40347. Trying to figure out right now whether this is intentional or not.

[lucacasonato]

Yup, definitely a bug.

[lucacasonato]

Fixed in #25207