Don't send empty String in place of no body

[jroper]

XMLHttpRequest.send spec defines different semantics for an empty string as compared to null, any string, whether empty or not, should be sent with a Content-Type of text/plain, whereas null should have no Content-Type header set. Since the user hasn't passed in content to send, the latter should be used.

See http://www.w3.org/TR/XMLHttpRequest/#the-send()-method

Combined with this bug in WebKit based browsers:

https://code.google.com/p/chromium/issues/detail?id=172802

This means when no body is supplied, the Content-Type ends up being application/xml, which for an empty String, means the body is invalid according to the content type. This causes issues for web servers that automatically parse the body according to the declared content type, such as this issue in Play framework:

playframework/playframework#1676

[mary-poppins]

Thanks for the PR!

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Thanks again for your help!

[jroper]

CLA signed and commit message updated according to conventions.

[benmccann]

+1 to this. thanks james for finding this issue!

[petebacondarwin]

@jroper - thanks for this. Can you provide a unit test that shows the wrong behaviour before your fix?

[jroper]

I'm happy to do this, but I followed the instructions here to get an angular development environment setup:

http://docs.angularjs.org/misc/contribute

In short, I already had Java, node and npm installed, so I ran these commands:

sudo npm install -g grunt-cli
sudo npm install -g bower
cd angular.js
npm install
bower install

and then I ran

grunt package

and got this:

$ grunt package

module.js:340
    throw err;
          ^
Error: Cannot find module 'coffee-script'
    at Function.Module._resolveFilename (module.js:338:15)
    at Function.Module._load (module.js:280:25)
    at Module.require (module.js:362:17)
    at require (module.js:378:17)
    at Object.<anonymous> (/Users/jroper/src/angular.js/node_modules/grunt/lib/grunt.js:16:1)
    at Module._compile (module.js:449:26)
    at Object.Module._extensions..js (module.js:467:10)
    at Module.load (module.js:356:32)
    at Function.Module._load (module.js:312:12)
    at Module.require (module.js:362:17)

I'm not a grunt, npm or bower user, I have no idea where to start to work out what's gone wrong here. If you can help me get my dev environment setup I'll be happy to write the tests.

[jroper]

I figured it out, I had an old version of npm, after updating npm, and doing git clean, I got everything working.

I've added a test, and I also ran it without my change to make sure it failed.

[btford]

Landed as 0d0330a.

Thanks!