517262 - FlexibleWrapper error when using wrapped constructors

Status: RESOLVED WONTFIX

(Mozilla Labs :: Jetpack Prototype, defect)

Description

[Drew Willcoxon :adw]

Attachment: Simple test case

I expose a constructor to content features from my chrome lib, and when they use it they get a cryptic error involving FlexibleWrapper.

Attached is a test-case patch to jetpack-environment.js.  It exposes two constructors, F and G.  They are the same, except G calls a member function baz(), and when I try to create an instance of G from content, I get this error and stack:

  TypeError: this.baz is not a function

  G()@chrome://jetpack/content/js/jetpack-environment.js:329
  call(G,[object FlexibleWrapper],[object Object],[object Array])@chrome://jetpack/content/js/secure-membrane.js:285
  construct(G,[object FlexibleWrapper],[object Object],[object Array])@chrome://jetpack/content/js/secure-membrane.js:267
  @:0
  @file:///Users/adw/Library/Application%20Support/Firefox/Profiles/beb1kaoj.jetpack2/jetpack-editor-code.txt:29

G is like the constructor I expose in my chrome lib.  When I create an instance of F, I get undefined instead of an object.

If you run this code in Bespin, you can test the patch:

  // f is undefined.
  var f = new jetpack.foo.F();
  console.log(typeof(f));

  // Raises the error above.
  var g = new jetpack.foo.G();

Also attached is a patch to test-secure-membrane.js.  It simply wraps a trusted function and an untrusted function and makes sure when they're used as constructors they yield objects.

Comment 1

[Drew Willcoxon :adw]

Attachment: test-secure-membrane.js patch

Comment 2

[Daniel Buchner [:dbuc]]

We will be monitoring all these issues after the rebooted Jetpack code base is released in the first week of March to ensure their causes are not duplicated. Many of the bugs/issues with the prototype version of Jetpack will be made irrelevant given the structure of the new SDK.