What is "Content-Disposition: file" ? about formdata HOT 4 CLOSED

Hi Conrad,

IETF RFC 2388 section 4.4 mentions the "file" disposition which may be used in the case of multiple files within a sub-part.

We tried to code the library to handle all the cases that might reasonably be expected to show up. In any of these cases:

• If the filename parameter is set in a Content-Disposition of a subpart,
• if the Content-Type header exists in a subpart,
• if a Content-Disposition of a subpart is set to "file"

...then that part of the whole is interpreted as a File and we move to the CapturingFile state.

Hope that helps, and feel free to ask for more details if you need them. If you see anything that looks wrong, I certainly would like to know.

Thanks,
Mike

from formdata.

Hi Mike,

Thanks for the explanations 👍

I agree with you that this all makes a lot of sense.

I wonder why the new RFC 7578, which obsoletes 2388, does not mention the Content-Disposition: file. That sounds like a breaking change in the RFC. Or maybe I missed the part about Content-Disposition: file there as well ?

Thanks again,
Conrad

from formdata.

RFC 7578 part 4.3 deprecates the use of multipart/mixed within multipart/form-data. Clients certainly should not be producing such things any more. However, we like to be resilient; if some client uses it, we understand it.

I suppose the IETF should have deprecated it in two steps: step 1 - clients no longer writing requests this way, and step 2 - servers no longer need to recognize them. But that did not seem to happen.

from formdata.

Great to hear you're being resilient :-)

Thanks for everything !

Edit: I had misunderstoof the obsoleted RFC before. I hadn't understood that Content-Disposition: file was only to be used in a subpart of multipart/mixed. This all makes a lot more sense now.

from formdata.