@astrojs/sitemap: generate wrong link

[BeanWei]

Astro Info

Astro                    v4.1.2
Node                     v18.18.0
System                   Linux (x64)
Package Manager          npm
Output                   server
Adapter                  @astrojs/node
Integrations             @astrojs/sitemap

If this issue only occurs in one browser, which browser is a problem?

No response

Describe the Bug

import { defineConfig } from 'astro/config';
import sitemap from '@astrojs/sitemap';
import node from '@astrojs/node';

// https://astro.build/config
export default defineConfig({
  site: 'https://astro.build',
  base: '/hello',
  output: 'server',
  adapter: node({
    mode: 'standalone',
  }),
  integrations: [sitemap()],
});

sitemap generate wrong link: https://astro.build/helloworld/

What's the expected result?

https://astro.build/hello/world/

Link to Minimal Reproducible Example

https://stackblitz.com/edit/github-85nlia

Participation

• I am willing to submit a pull request for this issue.

[BeanWei]

astro/packages/integrations/sitemap/src/index.ts

Lines 111 to 114 in d38b2a4

	* remove the initial slash from relative pathname
	* because `finalSiteUrl` always has trailing slash
	*/
	const fullPath = finalSiteUrl.pathname + r.generate(r.pathname).substring(1);

why because finalSiteUrl always has trailing slash ?

[andremralves]

Apparently it happens only with ssr adapters.