1156137 - EventSource only works with HTTP channels

Status: NEW

(Core :: DOM: Core & HTML, defect)

Description

[Boris Zbarsky [:bzbarsky]]

Per spec, EventSource should work with any channel.  And this simple testcase works in Chrome:

<script>
  var e = new EventSource("data:text/event-stream;charset=UTF-8,data:hey%0a%0a");
  e.addEventListener("message", function(e) {
    alert(e.data);
    this.close();
  })
</script>

There's a bunch of stuff in EventSource code that prevents this from working:

1)  Explicit checks for the http/https schemes in EventSource::CheckCanRequestSrc.

2)  What looks like a bogus use of DISALLOW_INHERIT_PRINCIPAL in the same function.

3)  QIs to nsIHttpChannel various places.

This code needs to be weaned off its HTTP dependency, really.

Comment 1

[Boris Zbarsky [:bzbarsky]]

Attachment: Start of a patch, before I realized just how HTTP-specific this code is

Comment 2

[Anne (:annevk)]

Does it really make sense to make this generic though? Requiring http/https seems okay to me. But I guess we'd need to convince Chrome.

Comment 3

[Boris Zbarsky [:bzbarsky]]

Sure.  Either we need to get the spec changed and convince Chrome to change or implement the spec or something.

Comment 4

[Jonas Sicking (:sicking) No longer reading bugmail consistently]

Given that this API is mainly syntax sugar on top of XHR/fetch(), I don't really have any opinion either way.

Comment 5

[Anne (:annevk)]

Persuaded by Ian that we should fix this. With a "Fetch layer" this would work automatically.