Default Request Headers are double added on Android

[daniel-rck]

Describe the bug
A HttpClient with client.DefaultRequestHeaders.Add("x-api-key", myApiKey); is signed correctly, but the client itself adds the header twice into the request:

"Headers": [
{
  "Key": "x-api-key",
  "Value": [
    "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx",
    "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
  ]
},
{
  "Key": "X-Amz-Date",
  "Value": [
...
}

To Reproduce
Steps to reproduce the behavior:
Try this code:

var client = new HttpClient();
client.DefaultRequestHeaders.Add("x-api-key", accessToken);

// do a random request
var response = await client.GetAsync(requestUri, cancellationToken, regionName, serviceName, credentials);

You can see the request object before sending here.

Compare to the request object that is return in response.RequestMessage.

Expected behavior
The Request Header should contain the header "x-api-key" only once. Like this:

"Headers": [
{
  "Key": "x-api-key",
  "Value": [
    "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
  ]
},
{
  "Key": "X-Amz-Date",
  "Value": [
...
}

Environment (please complete the following information):

• AWS API Gateway]
• OS: Android 8.0
• .NET version: Mono.Android

Additional context
I have tested an .NET Core 2.1 Console application where everything runs fine.

[FantasticFiasco]

I'll be damned, I though the .NET behavior was identical on all platforms.

I'll take a look at #29, but I am currently on holiday and wont be able to release anything until tonight or tomorrow night. Is there a way for you to work around this issue until the new version is released?

[daniel-rck]

Nevermind, I'm using my own fork right now - at least until there is a fixed version released.
Thank you and keep up the good work! :)

[FantasticFiasco]

I've released a preview on www.nuget.org. Would it be possible for you to verify that this preview is working in your environment? In case it does, I will continue with releasing the official version.

[daniel-rck]

👍 works with 1.0.2-sha-2b78963.

[FantasticFiasco]

The new official v1.0.2 is now live on www.nuget.org.

Thank you so much for reporting this issue, and good luck to you on your future development adventures!

[daniel-rck]

Thank you for the fast response and fix, all the best likewise :)