fix: preserve request_context when cloning/constructing Request objects

`server.upgrade()` relies on the internal `request_context` field to
perform WebSocket upgrades. When a Request was cloned via `req.clone()`
or constructed via `new Request(url, req)`, the `request_context` was
not copied to the new object, causing `server.upgrade()` to return
`false`.

Closes #11382

Co-Authored-By: Claude <noreply@anthropic.com>

src/bun.js/webcore/Request.zig

@@ -703,6 +703,8 @@ pub fn constructInto(globalThis: *jsc.JSGlobalObject, arguments: []const jsc.JSV
                         },
                     }
                 }
+
+                req.request_context = request.request_context;
             }
 
             if (value.asDirect(Response)) |response| {
@@ -1067,6 +1069,7 @@ pub fn cloneInto(
         .method = this.method,
         .flags = this.flags,
         .#headers = headers,
+        .request_context = this.request_context,
     };
 
     if (this.signal) |signal| {

test/regression/issue/11382.test.ts

@@ -0,0 +1,104 @@
+import { describe, expect, test } from "bun:test";
+
+describe("server.upgrade() with non-original Request", () => {
+  test("new Request(req.url, req) should upgrade successfully", async () => {
+    using server = Bun.serve({
+      port: 0,
+      fetch(req, server) {
+        const newReq = new Request(req.url, req);
+        if (server.upgrade(newReq)) return;
+        return new Response("Upgrade failed", { status: 500 });
+      },
+      websocket: {
+        open(ws) {
+          ws.send("hello");
+        },
+        message() {},
+      },
+    });
+
+    const { promise, resolve, reject } = Promise.withResolvers<string>();
+    const ws = new WebSocket(`ws://localhost:${server.port}`);
+    ws.onmessage = e => resolve(e.data);
+    ws.onerror = () => reject(new Error("WebSocket error"));
+
+    expect(await promise).toBe("hello");
+    ws.close();
+  });
+
+  test("req.clone() should upgrade successfully", async () => {
+    using server = Bun.serve({
+      port: 0,
+      fetch(req, server) {
+        const cloned = req.clone();
+        if (server.upgrade(cloned)) return;
+        return new Response("Upgrade failed", { status: 500 });
+      },
+      websocket: {
+        open(ws) {
+          ws.send("hello");
+        },
+        message() {},
+      },
+    });
+
+    const { promise, resolve, reject } = Promise.withResolvers<string>();
+    const ws = new WebSocket(`ws://localhost:${server.port}`);
+    ws.onmessage = e => resolve(e.data);
+    ws.onerror = () => reject(new Error("WebSocket error"));
+
+    expect(await promise).toBe("hello");
+    ws.close();
+  });
+
+  test("new Request(req) should upgrade successfully", async () => {
+    using server = Bun.serve({
+      port: 0,
+      fetch(req, server) {
+        const newReq = new Request(req);
+        if (server.upgrade(newReq)) return;
+        return new Response("Upgrade failed", { status: 500 });
+      },
+      websocket: {
+        open(ws) {
+          ws.send("hello");
+        },
+        message() {},
+      },
+    });
+
+    const { promise, resolve, reject } = Promise.withResolvers<string>();
+    const ws = new WebSocket(`ws://localhost:${server.port}`);
+    ws.onmessage = e => resolve(e.data);
+    ws.onerror = () => reject(new Error("WebSocket error"));
+
+    expect(await promise).toBe("hello");
+    ws.close();
+  });
+
+  test("original req should still upgrade after clone", async () => {
+    using server = Bun.serve({
+      port: 0,
+      fetch(req, server) {
+        // Clone the request but upgrade the original
+        const _cloned = req.clone();
+        if (server.upgrade(req)) return;
+        return new Response("Upgrade failed", { status: 500 });
+      },
+      websocket: {
+        open(ws) {
+          ws.send("hello");
+        },
+        message() {},
+      },
+    });
+
+    const { promise, resolve, reject } = Promise.withResolvers<string>();
+    const ws = new WebSocket(`ws://localhost:${server.port}`);
+    ws.onmessage = e => resolve(e.data);
+    ws.onerror = () => reject(new Error("WebSocket error"));
+
+    expect(await promise).toBe("hello");
+    ws.close();
+  });
+});