Use form-data subtype for multipart requests.

[lukaciko]

Use form-data content type for multipart requests. Closes #1092.

I don't especially like how this stretches over multiple classes. Perhaps RequestBuilder should be responsible for creating the right part headers.

[JakeWharton]

Thanks. I'll look soon.

[TheGhoul21]

I think that the header for the Part of a file is missing the filename as well.

Part part = (Part) methodParameterAnnotation;
            com.squareup.okhttp.Headers headers = com.squareup.okhttp.Headers.of(
                "Content-Disposition", "form-data; name=\"" + part.value() + "\";filename=\"file.jpg\"",
                "Content-Transfer-Encoding", part.encoding());

This fixed at least for me

[wKovacs64]

I think e8431de only solved most of #1092. The tail end of the 3rd bullet point was left out:

and optionally also add the filename parameter

[lukaciko]

The filename is required by some backend configurations. In Retrofit 1.9 you could set the filename by creating a TypedFile class, but that class doesn't exist anymore. I think it would be best if you open a new issue.