FormData wrapper breaks XMLHttpRequest#send(FormData) in Firefox

[kegluneq]

XMLHttpRequest does not unwrap the FormData object when sending, causing the following error in Firefox:

NS_ERROR_XPC_JSOBJECT_HAS_NO_FUNCTION_NAMED: JavaScript component does not have a method named: "available"'JavaScript component does not have a method named: "available"' when calling method: [nsIInputStream::available]
request.send(formData);

Screenshot

Example:

<script src="platform.js"></script>
<script>
  function doIt() {
    var request = new XMLHttpRequest();
    request.open('POST', '//localhost:8000/handle');
    request.send(new FormData());
  }
</script>
<a href="javascript:doIt();">Click</a>

Removing the platform.js script tag or executing the following code fixes the issue:

var oldSend = XMLHttpRequest.prototype.send; XMLHttpRequest.prototype.send = function(arg) { oldSend.call(this, unwrap(arg)); };

Browser: Firefox 31.0, Mozilla Firefox for Ubuntu canonical - 1.0
Platform: 0.3.5
ShadowDOM: c4da63735ba6c00a7d6af5c1b118f84bd6a2e114

[jmesserly]

Sounds like we can just wrap XHR.send ... taking a look

[kevinc]

any updates on this? just ran into this as well

[arv]

Wrapping XMLHttpRequest.prototype.send to do unwrapIfNeeded should be sufficient.

[jmesserly]

doh, got distracted by other stuff. looks like I have a half finished branch with the code change but not a test yet... adding that now