[Bug] Android: malformed empty multipart requests

[silviogutierrez]

Describe the bug

First of all: thanks for all your work on this library. It's a life saver with cookies and avoiding CORS.

On Android only, if you post multipart with an empty FormData object, the boundary is not set. This is invalid and some frameworks will refuses to parse the request. See here: https://stackoverflow.com/questions/34326150/multipartparsererror-invalid-boundary

Note: only happens on Android, not on iOS. I don't know much Android native dev, but I added a few breakpoints and startPart in HttpRequest.java is not called for empty requests. So the boundary is missing. See screenshots.

System info

• affected HTTP plugin version: all versions higher than and including 2.3.1
• affected platform(s) and version(s): Android
• affected device(s): all

Minimum viable code to reproduce

Using ionic's wrapper:

await HTTP.sendRequest(url, {
  method: "post",
  serializer: "multipart",
  data: new FormData(),
})

Screenshots
With data:

Without data (bug):

[silkimen]

Hi Silvio, I've checked how an empty FormData instance is handled in AFNEtworking (on iOS). It's just falling back to an empty url encoded request instead, which seemed strange at first sight. But on the other hand: it never caused problems as yet and sending empty multipart requests should be an extremely rare case. So I've decided to match this behavior on Android. This issue will be fixed in 3.1.1. 🤗

[silviogutierrez]

Great! Thanks for fixing this. An empty urlencoded request will still be parsed cleanly. So while strange, it's better than a loud error on certain frameworks. Thanks again.

…

On Sun, Oct 18, 2020 at 10:40 PM Sefa Ilkimen ***@***.***> wrote: Hi Silvio, I've checked how an empty FormData instance is handled in AFNEtworking (on iOS). It's just falling back to an empty url encoded request instead, which seemed strange at first sight. But on the other hand: it never caused problems as yet and sending empty multipart requests should be an extremely rare case. So I've decided to match this behavior on Android. This issue will be fixed in 3.1.1. 🤗 — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#372 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAAWVGEA7ZUGEAXZIZBGR4LSLORIRANCNFSM4SBDDGVQ> .

[zdevaty]

Hello @silkimen, can you please tag the 3.1.1 for release?