SSR redirects a redirectTo that uses a route parameter to the literal :id instead of the parameter value #34410

Command

serve, build

Is this a regression?

• Yes, this behavior used to work in the previous version

The previous version in which this bug was not present was

No response

Description

With server rendering, a route whose redirectTo reuses one of its own route parameters is redirected to the literal parameter name. The Angular router substitutes the matched parameter on the client:

export const routes: Routes = [
  { path: 'old/:id', redirectTo: 'new/:id' },
  { path: 'new/:id', component: Detail },
];

• Client-side navigation to /old/5 ends up at /new/5.
• A server-rendered request for /old/5 responds 302 with Location: /new/:id.

resolveRedirectTo in packages/angular/ssr/src/routes/ng-routes.ts replaces parameters of the parent route with *, but leaves :id in the redirectTo string unchanged. buildPathWithParams in packages/angular/ssr/src/utils/url.ts then only fills * segments from the request path, so the :id placeholder is never replaced.

Minimal Reproduction

ng new repro --ssr --defaults   # outputMode: server

Routes as above, serverRoutes with { path: '**', renderMode: RenderMode.Server }, then:

ng build && node dist/repro/server/server.mjs
curl -i http://localhost:4000/old/5

Exception or Error

HTTP/1.1 302 Found
Location: /new/:id

Expected `Location: /new/5`.

Your Environment

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Angular CLI       : 22.0.5
Node.js           : 24.15.0
Package Manager   : yarn 1.22.22
Operating System  : darwin arm64

Anything else relevant?

No response