762958 - Exception... "Can't find engine in store!" in tests browser_483086.js, browser_addEngine.js

Status: RESOLVED WORKSFORME

(Firefox :: Search, defect)

Description

[David Teller [:Yoric] - still alive but not very active]

Reading the logs of tests browser_483086.js and browser_addEngine.js shows the following (caught and logged) exception, repeated several times:

TEST-INFO | chrome://mochitests/content/browser/browser/components/search/test/browser_483086.js | Console message: [JavaScript Error: "[Exception... "Can't find engine in store!"  nsresult: "0x8000ffff (NS_ERROR_UNEXPECTED)"  location: "JS frame :: file:///Users/david/Documents/Code/mozilla-central-promises/obj-x86_64-apple-darwin11.4.0/dist/Nightly.app/Contents/MacOS/components/nsSearchService.js :: FAIL :: line 247"  data: no]" {file: "file:///Users/david/Documents/Code/mozilla-central-promises/obj-x86_64-apple-darwin11.4.0/dist/Nightly.app/Contents/MacOS/components/nsSearchService.js" line: 247}]

Upon investigation, the situation seems to be the following:
- test adds search engine;
- service fires "engine-added" then backgrounds actual loading of the engine;
- upon "engine-added", test removes engine;
- service removes engine;
- once engine is loaded, service attempts to set it as current engine;
- as engine has been removed, service raises exception;
- service catches exception.

While this is hardly fatal, the existence of this race condition is a bit worrying.

Comment 1

[:Gavin Sharp [email: [e-mail]]]

(In reply to David Rajchenbach Teller [:Yoric] from comment #0)
> Upon investigation, the situation seems to be the following:
> - test adds search engine;
> - service fires "engine-added" then backgrounds actual loading of the engine;

Are you sure? This should be impossible - _addEngineToStore (which fires the "added" notification) should only be called once the load is complete.

Comment 2

[Mark Banner (:standard8)]

I just ran both of these tests on latest mozilla-central and neither of them generate the error any more.