1139434 - NPAPI race conditions due to IPC

Status: RESOLVED WONTFIX

(Firefox :: Untriaged, defect)

Description

[Ioan-Cosmin Szanto]

Attachment: IcpAssumedBug.zip

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:35.0) Gecko/20100101 Firefox/35.0
Build ID: 20150223114739

Steps to reproduce:

I have one plugin which can create two types of instances and I can add one to another using JavaScript. I create the second instance in js added it to the document and try to add it ti the second plugin, but the second instance is not created in time. NPN_Invoke on the first object is called earlier than NPP_New for the second instance.
I've attached a test.


Actual results:

The object which is given to NPN_Invoke for the first instance is an uninitialized object.


Expected results:

The second instance of the object should have been created when it was added to the document, earlier than the invoke to the first instance.

Comment 1

[Benjamin Smedberg]

    function onAdd() {
      document.getElementById("added").innerHTML = "";
      var a = document.getElementById("a");
      var b = document.createElement("embed");
      b.setAttribute("type", "application/x-b");

      document.getElementById("added").appendChild(b);
      // The following will force the object creation
      // b.getId();
      try {
        a.add(b);
        console.log("Success");
      }
      catch(e) {
        console.error(e);
      }
    }

So you have the workaround already, which is to script instance B before you pass it to instance A. I think this is an intentional behavior of Firefox and so this is not a bug.