Catch-all routes duplicates custom headers

[zanettin]

Astro Info

Astro                    v4.16.10
Node                     v18.20.3
System                   Linux (x64)
Package Manager          npm
Output                   server
Adapter                  @astrojs/node
Integrations             none

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

Describe the Bug

Setting a custom header (X-Debug in the attached repro), the values are duplicated when returning a response on the catch-all ([...slug].astro) route.

Reproduction

• run npm run build && npm run preview
• open dev tools -> network
• go to any URI but not home
• checking X-Debug header which has the value 1234, 1234

What's the expected result?

X-Debug header should have value 1234 also on catch-all routes

Link to Minimal Reproducible Example

https://codesandbox.io/p/devbox/focused-cartwright-hjrw7n?workspaceId=858df2c7-b16d-4601-b40c-e4a00d04da47

Participation

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

[ematipico]

I can't replicate, can you please at least tell us which browser you're using?

Here's what I get on firefox (raw headers)

HTTP/1.1 500 Internal Server Error
Access-Control-Allow-Origin: *
content-type: text/plain;charset=UTF-8
x-debug: 1234
Date: Mon, 18 Nov 2024 14:21:25 GMT
Connection: keep-alive
Keep-Alive: timeout=5
Transfer-Encoding: chunked

[zanettin]

Thank you very much @ematipico for having a look at this issue and sorry if my description was not clear. i've recorded a short video to demonstrate the point i've tried to mention above. important is, that i am talking about the built version of the app and not the dev mode. since the headers are set on SSR it doesn't have an impact which browser is used. if i can give you further info, please let me know 🙏

2024-11-20.16-43-51.mp4