From deb48d8c7491e738c4c614dbc8ea7f495a50e7bb Mon Sep 17 00:00:00 2001
From: Sheraff <fpellet@ensc.fr>
Date: Sun, 25 Jan 2026 18:58:15 +0100
Subject: [PATCH] refactor(router-core): throw redirect w/ a pre-build location
 doesn't need to re-parse from string

---
 packages/router-core/src/redirect.ts | 26 +++++++++++++++++++++++---
 packages/router-core/src/router.ts   | 12 ++++++++----
 2 files changed, 31 insertions(+), 7 deletions(-)

diff --git a/packages/router-core/src/redirect.ts b/packages/router-core/src/redirect.ts
index 31aaa2f32c7..4cb1e0f5e22 100644
--- a/packages/router-core/src/redirect.ts
+++ b/packages/router-core/src/redirect.ts
@@ -1,6 +1,7 @@
 import { SAFE_URL_PROTOCOLS, isDangerousProtocol } from './utils'
 import type { NavigateOptions } from './link'
 import type { AnyRouter, RegisteredRouter } from './router'
+import type { ParsedLocation } from './location'
 
 export type AnyRedirect = Redirect<any, any, any, any, any>
 
@@ -14,7 +15,13 @@ export type Redirect<
   TMaskFrom extends string = TFrom,
   TMaskTo extends string = '.',
 > = Response & {
-  options: NavigateOptions<TRouter, TFrom, TTo, TMaskFrom, TMaskTo>
+  options: NavigateOptions<TRouter, TFrom, TTo, TMaskFrom, TMaskTo> & {
+    /**
+     * @internal
+     * A **trusted** built location that can be used to redirect to.
+     */
+    _builtLocation?: ParsedLocation
+  }
   redirectHandled?: boolean
 }
 
@@ -45,6 +52,11 @@ export type RedirectOptions<
    * @link [API Docs](https://tanstack.com/router/latest/docs/framework/react/api/router/RedirectType#headers-property)
    */
   headers?: HeadersInit
+  /**
+   * @internal
+   * A **trusted** built location that can be used to redirect to.
+   */
+  _builtLocation?: ParsedLocation
 } & NavigateOptions<TRouter, TFrom, TTo, TMaskFrom, TMaskTo>
 
 export type ResolvedRedirect<
@@ -113,13 +125,21 @@ export function redirect<
   opts.statusCode = opts.statusCode || opts.code || 307
 
   // Block dangerous protocols in redirect href
-  if (typeof opts.href === 'string' && isDangerousProtocol(opts.href)) {
+  if (
+    !opts._builtLocation &&
+    typeof opts.href === 'string' &&
+    isDangerousProtocol(opts.href)
+  ) {
     throw new Error(
       `Redirect blocked: unsafe protocol in href "${opts.href}". Only ${SAFE_URL_PROTOCOLS.join(', ')} protocols are allowed.`,
     )
   }
 
-  if (!opts.reloadDocument && typeof opts.href === 'string') {
+  if (
+    !opts._builtLocation &&
+    !opts.reloadDocument &&
+    typeof opts.href === 'string'
+  ) {
     try {
       new URL(opts.href)
       opts.reloadDocument = true
diff --git a/packages/router-core/src/router.ts b/packages/router-core/src/router.ts
index 63044b141f2..20041fd05f7 100644
--- a/packages/router-core/src/router.ts
+++ b/packages/router-core/src/router.ts
@@ -2292,8 +2292,11 @@ export class RouterCore<
       // always uses this.origin when constructing URLs
       if (this.latestLocation.publicHref !== nextLocation.publicHref) {
         const href = this.getParsedLocationHref(nextLocation)
-
-        throw redirect({ href })
+        if (nextLocation.external) {
+          throw redirect({ href })
+        } else {
+          throw redirect({ href, _builtLocation: nextLocation })
+        }
       }
     }
 
@@ -2622,8 +2625,9 @@ export class RouterCore<
   resolveRedirect = (redirect: AnyRedirect): AnyRedirect => {
     const locationHeader = redirect.headers.get('Location')
 
-    if (!redirect.options.href) {
-      const location = this.buildLocation(redirect.options)
+    if (!redirect.options.href || redirect.options._builtLocation) {
+      const location =
+        redirect.options._builtLocation ?? this.buildLocation(redirect.options)
       const href = this.getParsedLocationHref(location)
       redirect.options.href = href
       redirect.headers.set('Location', href)