Shouldn't the response header returned by Chrome say "4-138724" then though, and not "4-1943507"? The synthesized response body doesn't include bytes "138725-1943507".
Ah - I need to remember to coffee before posting in the AM.
Yes, the mismatch between the response headers and the content is a problem. Unfortunately, IME browsers often do "fix ups" of headers that make them less than reliable, this might be one of them -- it's effectively rewriting the response but failing to update all of the metadata.
The bug summary says "Chrome returns wrong status code while using range header with caches." That's indeed not a bug. I think the most concerning thing here is that the Content-Range header is obviously incorrect, so Chrome should either be updating it or producing a clear error to alert you -- which it looks like the Chrome dev acknowledges when they say "it is probably a bug that there is no AbortError exception on the read".
Yes, the mismatch between the response headers and the content is a problem. Unfortunately, IME browsers often do "fix ups" of headers that make them less than reliable, this might be one of them -- it's effectively rewriting the response but failing to update all of the metadata.
The bug summary says "Chrome returns wrong status code while using range header with caches." That's indeed not a bug. I think the most concerning thing here is that the Content-Range header is obviously incorrect, so Chrome should either be updating it or producing a clear error to alert you -- which it looks like the Chrome dev acknowledges when they say "it is probably a bug that there is no AbortError exception on the read".
I might try to add some tests for this to https://cache-tests.fyi/#partial