vidraj

(This doesn't even require two clients: A single client who edits the first query, reformatting it on multiple lines to get better error information, would run into the same problem.)

Yes, I'm assuming the presence of a working, HTTP-semantics-compliant shared cache.

It's not heuristic caching here, the response has an explicit Cache-Control header. From [RFC 9111](https://www.rfc-editor.org/rfc/rfc9111.html#name-storing-responses-in-caches) (excerpt): > A cache MUST NOT store a response to a request unless: > -...

And this is not just a hypothetical – real-world implementations behave like this, at least according to the excellent page (under “An optimal HTTP cache reuses a fresh 400 response...

> So why would the origin server want to make the response cacheable? I have three answers to that: 1. Why wouldn't it? If you send the same request, you...