The Content-Length header is not included in requests

Bug Report

Description

The Content-Length header is not included in requests. I did not find out how to prevent this. Is it intentional or actually a bug? I did not find relevant documentation on this behavior of Fuel .

This keeps Fuel ⛽ from being used for APIs that respond with HTTP 411 is the field is not present. This is the case for example with the Google Play Developer API.

To Reproduce

Code to reproduce the behavior:

import com.github.kittinunf.fuel.Fuel
import com.github.kittinunf.fuel.core.Headers

println(Fuel
        .post("https://httpbin.org/anything")
        .header(Headers.CONTENT_LENGTH, "0")
        .responseString()
        .third
        .component1())

Output:

{
  "args": {}, 
  "data": "", 
  "files": {}, 
  "form": {}, 
  "headers": {
    "Accept": "text/html, image/gif, image/jpeg, *; q=.2, */*; q=.2", 
    "Content-Type": "application/x-www-form-urlencoded", 
    "Host": "httpbin.org", 
    "User-Agent": "Java/13.0.1", 
    "X-Amzn-Trace-Id": "Root=1-XXXXXXX-XXXXXXXXXXXXXXXXX"
  }, 
  "json": null, 
  "method": "POST", 
  "origin": "--------", 
  "url": "https://httpbin.org/anything"
}

Expected behavior

A clear and concise description of what you expected to happen.

Environment

Development Machine

• OS: Windows 10
• Fuel version: 2.2.2
• Kotlin version: 1.3.72 @ Java/13.0.1

[felixdivo]

Yes, that actually fixes it:

     private fun setBodyIfDoOutput(connection: HttpURLConnection, request: Request) {
         val body = request.body
-        if (!connection.doOutput || body.isEmpty()) {
+        if (!connection.doOutput) {
+            return
+        }
+        if (body.isEmpty()) {
+            connection.setFixedLengthStreamingMode(0L)
             return
         }

Is that change wanted/should I open a PR?

[SleeplessByte]

Yes this is great.