843500 - TypeError: this._browser is null

Status: RESOLVED FIXED

(Add-on SDK Graveyard :: General, defect, P2)

Description

[Erik Vold [:erikvold] (please needinfo? me)]

When I run `cfx test -v` I see the following output quite a bit:

TypeError: this._browser is null
resource://a941fec9-6704-4eef-8185-e6ebce6a6439-at-jetpack/addon-sdk/lib/sdk/tabs/tab-firefox.js 50
Traceback (most recent call last):
  File "chrome://browser/content/browser.xul", line 1, in onselect
    <?xml version="1.0"?>
  File "chrome://browser/content/tabbrowser.xml", line 949, in updateCurrentBrowser
    this.mCurrentTab.dispatchEvent(event);
  File "resource://a941fec9-6704-4eef-8185-e6ebce6a6439-at-jetpack/addon-sdk/lib/sdk/tabs/observer.js", line 49, in handleEvent
    this._emit(EVENTS[event.type], event.target, event);
  File "resource://a941fec9-6704-4eef-8185-e6ebce6a6439-at-jetpack/addon-sdk/lib/sdk/deprecated/events.js", line 123, in _emit
    return this._emitOnObject.apply(this, args);
  File "resource://a941fec9-6704-4eef-8185-e6ebce6a6439-at-jetpack/addon-sdk/lib/sdk/deprecated/events.js", line 153, in _emitOnObject
    listener.apply(targetObj, params);
  File "resource://a941fec9-6704-4eef-8185-e6ebce6a6439-at-jetpack/addon-sdk/lib/sdk/tabs/observer.js", line 60, in onTabSelect
    if (selectedTab) observer._emit('deactivate', selectedTab);
  File "resource://a941fec9-6704-4eef-8185-e6ebce6a6439-at-jetpack/addon-sdk/lib/sdk/deprecated/events.js", line 123, in _emit
    return this._emitOnObject.apply(this, args);
  File "resource://a941fec9-6704-4eef-8185-e6ebce6a6439-at-jetpack/addon-sdk/lib/sdk/deprecated/events.js", line 153, in _emitOnObject
    listener.apply(targetObj, params);
  File "resource://a941fec9-6704-4eef-8185-e6ebce6a6439-at-jetpack/addon-sdk/lib/sdk/windows/tabs-firefox.js", line 99, in _onTabEvent
    let wrappedTab = Tab(options);
  File "resource://a941fec9-6704-4eef-8185-e6ebce6a6439-at-jetpack/addon-sdk/lib/sdk/tabs/tab-firefox.js", line 230, in Tab
    let tab = TabTrait(options);
  File "resource://a941fec9-6704-4eef-8185-e6ebce6a6439-at-jetpack/addon-sdk/lib/sdk/deprecated/traits.js", line 114, in Trait
    return self.constructor.apply(self, arguments) || self._public;
  File "resource://a941fec9-6704-4eef-8185-e6ebce6a6439-at-jetpack/addon-sdk/lib/sdk/tabs/tab-firefox.js", line 50, in Tab
    this._browser.addEventListener(EVENTS.ready.dom, this._onReady, true);
"]
info: addon-sdk: [JavaScript Error: "addon-sdk: An exception occurred.
TypeError: this._browser is null
resource://a941fec9-6704-4eef-8185-e6ebce6a6439-at-jetpack/addon-sdk/lib/sdk/tabs/tab-firefox.js 50
Traceback (most recent call last):
  File "chrome://browser/content/browser.xul", line

Comment 1

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

If this is actually causing test failures, feel free to bump it up to P1.

Comment 2

[Erik Vold [:erikvold] (please needinfo? me)]

(In reply to Wes Kocher (:KWierso) from comment #1)
> If this is actually causing test failures, feel free to bump it up to P1.

It's not which is worrying..

Comment 3

[Matteo Ferretti [:zer0] [:matteo]]

Actually I would say that the fact that the tests are not failing even if we have exceptions in tests, should be worthy to bump it to P1. For this such exception I would expect to don't have the tree green.

Comment 4

[Erik Vold [:erikvold] (please needinfo? me)]

Alex can you take a look at this one? I think it may be important for 1.14

Comment 5

[Alexandre Poirot [:ochameau]]

Attachment: Pull request 838

Wasn't an easy one... We are facing race conditions between concurrent tabs module instances loaded in different loaders...
(Each test-* file is now executed in its own loader instance)

Comment 6

[Alexandre Poirot [:ochameau]]

Knowing what was behind these exception was important,
but I'm not sure the actual issue is serious enough to be pushed to stabilization?

It isn't only test issue, but it only happen when a tab is removed during onOpen event and multiple addons are using tabs API. It won't fail if the tab is removed during onReady event, the race only happen with actions being done during TabOpen.

Comment 7

[[github robot]]

Commits pushed to master at https://github.com/mozilla/addon-sdk

https://github.com/mozilla/addon-sdk/commit/8ce14bdf76c38a13853fbb9bbbda782605685255
Bug 843500: Fix race condition in firefox tabs code between concurrent module instances.

https://github.com/mozilla/addon-sdk/commit/ea266834f3c3243dfd0a5f680988b2f3fa7477a8
Merge pull request #838 from ochameau/tabevents-race

Bug 843500: Fix race condition in firefox tabs code between concurrent module instances. r=mossop

Comment 8

[[github robot]]

Commit pushed to stabilization at https://github.com/mozilla/addon-sdk

https://github.com/mozilla/addon-sdk/commit/5da62e41172c9a46726c5a072b9e5538bf6e4889
Merge pull request #838 from ochameau/tabevents-race

Bug 843500: Fix race condition in firefox tabs code between concurrent module instances. r=mossop(cherry picked from commit ea266834f3c3243dfd0a5f680988b2f3fa7477a8)