333049 - Locking a complex preferences doesn't work properly

Status: RESOLVED WONTFIX

(Core :: Preferences: Backend, defect)

Description

[Mike Kaply [:mkaply]]

Easy to recreate

Create a new profile.

Go to about:config

search on browser.startup.homepage

right click - select "Lock"

click on the home button.

You get to see the source of browserconfig.properties.

Problem is in prefbranch - this code:

http://lxr.mozilla.org/seamonkey/source/modules/libpref/src/nsPrefBranch.cpp#249

if the pref is locked, we assume it is not a complex value. This is simply wrong.

locked prefs certainly can be complex values.

Comment 1

[Mike Kaply [:mkaply]]

even with that change, this code is still broken.

This whole "Guessing if we are a complex value" just seems wrong.

Shouldn't we do something simple like look at the result of the getCharPref and if it begins with chrome: or res: assume it is a complex value?

Comment 2

[Mike Kaply [:mkaply]]

incidentally, to see the other problem, after my fix is in, set the home page to http://www.yahoo.com in about:config, then lock the pref (note it reverts to a resource: url)

then click home - junk.

Comment 3

[Mike Kaply [:mkaply]]

Attachment: Patch per bsmedberg

OK, so here is the correct logic.

If it is a locked preference OR if a user pref has not been set, assume it is a complex value.

The only case where this won't work is if you try to set a non complex value as the default and lock it (for instance setting browser.startup.homepage to http://www.yahoo.com and then lock it)

If a preference was a localized preference in the browser and you want to lock it, you have to lock it using a localized preference as well (for instance the CCK)

Comment 4

[Benjamin Smedberg]

To do that you'd need

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

Comment 6

[Serge Gautherie (:sgautherie)]

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

Comment 7

[Mike Kaply [:mkaply]]

No idea why this got lost, but this is still broken.

And the code is still current.

Can I check in when I get my Hg state figured out?

Comment 8

[Mike Kaply [:mkaply]]

After further research, I'm going to WONTFIX this.

This patch would break locking a pref like this:

"browser.startup.homepage", "data:text/plain,browser.startup.homepage=http://www.yahoo.com/"

and this has kind of become the norm after all these years (because of this bug).

So I think at this point, folks are accustomed to things being broke and any attempts to "fix" would break other things.