CJK characters are broken.

[cheolhee]

CJK letters were broken when I sent strings with POST method.
I think this charset should be a default set because the NSData is made with NSUTF8StringEncoding.

mutableURLRequest.HTTPBody = query(parameters!).dataUsingEncoding(NSUTF8StringEncoding, allowLossyConversion: false)

[cnoon]

Is there any way you could provide a failing test for this change? That would help us debug to make a more informed decision.

[cnoon]

Thanks for your PR @cheolhee!

After much investigation, I've decided to merge this change in 21040ab. I've also added a test around the POST behavior in ba6d3dd.

With that said, I only made this change due to the fact you're seeing issues without the change. I cannot see any downsides to making the change. This thread makes me believe though that the charset should not really be required. Additionally, no actual unicode characters will ever make it into the HTTP body since all parameter key/value pairs are percent escaped prior to be encoded into UTF-8.

I'm assuming your server is requiring the charset when it actually shouldn't. Either way, as I mentioned, I cannot see any downsides to adding it.

For future reference, there's a good amount of information about the encoding algorithm here.