fix(chromium): preserve header overrides in redirects (#28962)

Reference https://github.com/microsoft/playwright/issues/28758

packages/playwright-core/src/server/chromium/crNetworkManager.ts

@@ -285,10 +285,16 @@ export class CRNetworkManager {
     let route = null;
     if (requestPausedEvent) {
       // We do not support intercepting redirects.
-      if (redirectedFrom || (!this._userRequestInterceptionEnabled && this._protocolRequestInterceptionEnabled))
-        this._session._sendMayFail('Fetch.continueRequest', { requestId: requestPausedEvent.requestId });
-      else
+      if (redirectedFrom || (!this._userRequestInterceptionEnabled && this._protocolRequestInterceptionEnabled)) {
+        let headers = undefined;
+        const previousHeaderOverrides = redirectedFrom?._originalRequestRoute?._alreadyContinuedParams?.headers;
+        // Chromium does not preserve header overrides between redirects, so we have to do it ourselves.
+        if (previousHeaderOverrides)
+          headers = network.mergeHeaders([headersObjectToArray(requestPausedEvent.request.headers, '\n'), previousHeaderOverrides]);
+        this._session._sendMayFail('Fetch.continueRequest', { requestId: requestPausedEvent.requestId, headers });
+      } else {
         route = new RouteImpl(this._session, requestPausedEvent.requestId);
+      }
     }
     const isNavigationRequest = requestWillBeSentEvent.requestId === requestWillBeSentEvent.loaderId && requestWillBeSentEvent.type === 'Document';
     const documentId = isNavigationRequest ? requestWillBeSentEvent.loaderId : undefined;
@@ -384,8 +390,6 @@ export class CRNetworkManager {
 
   _deleteRequest(request: InterceptableRequest) {
     this._requestIdToRequest.delete(request._requestId);
-    if (request._route)
-      request._route._alreadyContinuedParams = undefined;
     if (request._interceptionId)
       this._attemptedAuthentications.delete(request._interceptionId);
   }
@@ -508,6 +512,9 @@ class InterceptableRequest {
   readonly _timestamp: number;
   readonly _wallTime: number;
   readonly _route: RouteImpl | null;
+  // Only first request in the chain can be intercepted, so this will
+  // store the first and only Route in the chain (if any).
+  readonly _originalRequestRoute: RouteImpl | undefined;
   session: CRSession;
 
   constructor(options: {
@@ -529,6 +536,7 @@ class InterceptableRequest {
     this._interceptionId = requestPausedEvent && requestPausedEvent.requestId;
     this._documentId = documentId;
     this._route = route;
+    this._originalRequestRoute = route ?? redirectedFrom?._originalRequestRoute;
 
     const {
       headers,

tests/page/page-request-continue.spec.ts

@@ -395,13 +395,13 @@ it('should continue preload link requests', async ({ page, server, browserName }
 
 it('continue should propagate headers to redirects', async ({ page, server, browserName }) => {
   it.info().annotations.push({ type: 'issue', description: 'https://github.com/microsoft/playwright/issues/28758' });
-  it.fixme(browserName !== 'webkit');
+  it.fixme(browserName === 'firefox');
   await server.setRedirect('/redirect', '/empty.html');
   await page.route('**/redirect', route => {
     void route.continue({
       headers: {
         ...route.request().headers(),
-        'custom': 'value'
+        custom: 'value'
       }
     });
   });
@@ -412,6 +412,38 @@ it('continue should propagate headers to redirects', async ({ page, server, brow
   expect(serverRequest.headers['custom']).toBe('value');
 });
 
+it('continue should delete headers on redirects', async ({ page, server, browserName }) => {
+  it.info().annotations.push({ type: 'issue', description: 'https://github.com/microsoft/playwright/issues/13106' });
+  it.fixme(browserName === 'firefox');
+  await page.goto(server.PREFIX + '/empty.html');
+  server.setRoute('/something', (request, response) => {
+    response.writeHead(200, { 'Access-Control-Allow-Origin': '*' });
+    response.end('done');
+  });
+  await server.setRedirect('/redirect', '/something');
+  await page.route('**/redirect', route => {
+    void route.continue({
+      headers: {
+        ...route.request().headers(),
+        foo: undefined
+      }
+    });
+  });
+  const [text, serverRequest] = await Promise.all([
+    page.evaluate(async url => {
+      const data = await fetch(url, {
+        headers: {
+          foo: 'a',
+        }
+      });
+      return data.text();
+    }, server.PREFIX + '/redirect'),
+    server.waitForRequest('/something')
+  ]);
+  expect(text).toBe('done');
+  expect(serverRequest.headers.foo).toBeFalsy();
+});
+
 it('should intercept css variable with background url', async ({ page, server }) => {
   it.info().annotations.push({ type: 'issue', description: 'https://github.com/microsoft/playwright/issues/19158' });