264680 - Locking homepage causes getting default home page to fail

Status: RESOLVED INCOMPLETE

(Core :: Preferences: Backend, defect)

Description

[Ian Neal]

Using Build ID 2004101605 on WinXP SP2
If you set a lockPref for browser.startup.homepage it causes the following code
from pref-navigator.js
http://lxr.mozilla.org/seamonkey/source/xpfe/components/prefwindow/resources/content/pref-navigator.js#102
to fail:

function getDefaultPage()
{
  var prefService = Components.classes[PREFSERVICE_CONTRACTID]
                              .getService(nsIPrefService);
  var pref = prefService.getDefaultBranch(null);
  return pref.getComplexValue("browser.startup.homepage",
                              nsIPrefLocalizedString).data;
}
and gives the following error message in the JS console:
Error: uncaught exception: [Exception... "Component returned failure code:
0x80004005 (NS_ERROR_FAILURE) [nsIPrefBranch.getComplexValue]"  nsresult:
"0x80004005 (NS_ERROR_FAILURE)"  location: "JS frame ::
chrome://communicator/content/pref/pref-navigator.js :: getDefaultPage :: line
108"  data: no]

Comment 1

[[e-mail]]

Don't ask me why, but you cannot lock a localized pref to an arbitrary string,
it needs to be a properties file references like the default pref is.

Comment 2

[Met - Martin Hassman]

This is probably dupe of the bug #109932

Comment 3

[Serge Gautherie (:sgautherie)]

(Filter "spam" on 'prefs-nobody-20080612'.)

Comment 4

[Mike Kaply [:mkaply]]

I just verified that this still happens.

The simplest way to recreate is to set

pref("browser.startup.homepage", "http://www.yahoo.com");

in a new JS file in defaults\pref in Firefox.

You'll get the error:

Timestamp: 4/13/2012 10:29:34 AM
Error: homePref.value is null
Source File: chrome://browser/content/preferences/main.js
Line: 63

Comment 5

[Mike Kaply [:mkaply]]

So the issue is in this code:

http://mxr.mozilla.org/mozilla-central/source/toolkit/content/widgets/preferences.xml#312

browser.startup.homepage is a wstring, but if you set it as a pref (which people do), this code fails.

I think we should put a try catch around the code and use Components.interfaces.nsISupportsString if it fails.

Thoughts?