Cannot be parsed as a URL against "null" #5509

Which project does this relate to?

Router

Describe the bug

After upgrading from tanstack router 1.131.x to > 1.132.x we've encountered a Cannot be parsed as a URL against "null" error when bundled for production and deployed to our deployment target as thrown by a parseLocation method when attempting to construct a URL object

In our context we are using Tanstack Router in SPA mode and deploying to Veeva CRM (think of this as a CMS). Veeva serves the SPA using file: protocol and we've narrowed down that when this is performed window.origin returns the string literal "null"

as of >1.132.0 the following code exists in router.ts in router-core

this.origin = this.options.origin
    if (!this.origin) {
      if (!this.isServer) {
        this.origin = window.origin
      } else {
        // fallback for the server, can be overridden by calling router.update({origin}) on the server
        this.origin = 'http://localhost'
      }
    }

in our context this.options.origin is undefined, and this.isServer is false so this.origin = window.origin is invoked and as mentioned window.origin is "null" later when parseLocation is called the error is thrown when code like `new URL("/", this.origin) is invoked by tanstack router

I think we can reasonably workaround this by setting the origin when invoking createRouter for example

export const router = createRouter({
  routeTree,
  history: createHashHistory(),
  context: {
    queryClient,
  },
  origin: window.location.protocol === "file:" ? "http://localhost": undefined,
});

Your Example Website or App

n/a

Steps to Reproduce the Bug or Issue

n/a

Expected behavior

backwards compatible with 1.131.x in the handling of file protocol scenarios

Screenshots or Videos

No response

Platform

• Router / Start Version: > 1.132.0
• OS: iOS
• Browser: Safari
• Browser Version: [e.g. 91.1]
• Bundler: vite
• Bundler Version: 7.1.7

Additional context