Strip request-body-header when redirecting from a POST to GET

This doesn't change any expectation because we're not setting
response.redirected properly so all the tests fail later on when it's
asserted to be true.

Fixes #25257

components/net/http_loader.rs

@@ -25,7 +25,10 @@ use headers::{
 use headers::{AccessControlAllowOrigin, AccessControlMaxAge};
 use headers::{CacheControl, ContentEncoding, ContentLength};
 use headers::{IfModifiedSince, LastModified, Origin as HyperOrigin, Pragma, Referer, UserAgent};
-use http::header::{self, HeaderName, HeaderValue};
+use http::header::{
+    self, HeaderName, HeaderValue, CONTENT_ENCODING, CONTENT_LANGUAGE, CONTENT_LOCATION,
+    CONTENT_TYPE,
+};
 use http::{HeaderMap, Request as HyperRequest};
 use hyper::{Body, Client, Method, Response as HyperResponse, StatusCode};
 use hyper_serde::Serde;
@@ -804,8 +807,18 @@ pub fn http_redirect_fetch(
                 (*code == StatusCode::SEE_OTHER && request.method != Method::HEAD)
         })
     {
+        // Step 11.1
         request.method = Method::GET;
         request.body = None;
+        // Step 11.2
+        for name in &[
+            CONTENT_ENCODING,
+            CONTENT_LANGUAGE,
+            CONTENT_LOCATION,
+            CONTENT_TYPE,
+        ] {
+            request.headers.remove(name);
+        }
     }
 
     // Step 12

components/script/dom/response.rs

@@ -287,8 +287,7 @@ impl ResponseMethods for Response {
 
     // https://fetch.spec.whatwg.org/#dom-response-redirected
     fn Redirected(&self) -> bool {
-        let url_list_len = self.url_list.borrow().len();
+        return *self.redirected.borrow();
-        url_list_len > 1
     }
 
     // https://fetch.spec.whatwg.org/#dom-response-status