How do we distinguish between a short response and a complete response for diffs and patches?

The following discussion from !200 (merged) should be addressed:

• @nick.thomas started a discussion: (+3 comments)

  How does the client distinguish between a valid response and a short response without a content-length header? 🤔

This is anywhere in the code where we don't know how many bytes will be generated by an upstream process (gitaly or a git subprocess), and don't want to cache the whole response in memory before sending, so call w.Header().Del("Content-Length") to active chunked transfer encoding.

If the upstream process dies partway through, how does the client know that all the chunks that should be there, are there?

They get a 200 response and a number of chunks of data. They don't know what the size of the patch/diff should be, and they don't know how many chunks they should have received.

I can't see the solution offhand in https://tools.ietf.org/html/rfc7230#section-4.1 but didn't want to lose track of this.