": hi" occasionally added to messages

[Cyral]

I am finding that the text ": hi" is occasionally injected into event source streams. I traced it back to this line but I am not familiar enough with nchan to tell why this is being added or if it is a bug or not.

This only appears to be happening on iOS devices that are connected with server sent events. (Our error tracking software shows the device type and whatnot, and that is the only thing in common between users) We are seeing it happen in maybe one out of every few thousand sessions.

For example, we will send some JSON payload to nchan to be broadcasted, and it will arrive perfectly for most users but occasionally it will be delivered with ": hi", breaking the JSON payload:

{
    "type": "new",
     "data:": "some-text-goes-he: hi <-- err, unable to parse json