333808 - safe mode should disable userContent.css and userChrome.css

Status: RESOLVED FIXED

(Toolkit :: Startup and Profile System, enhancement)

Description

[Darin Fisher]

Safe mode should disable userContent.css and userChrome.css

Some extensions will go and add rules to userContent.css (e.g., flash block), and then when uninstalled they will not bother removing those rules.  As a result, a user's profile can be left in a broken state, where in the case of flash block, many flash pages will fail to work properly.  The symptoms are complicated by the fact that some flash content will still work.

I think it might help people debugging problems like this if they safe mode would disable userContent.css.  It'd probably make sense to disable userChrome.css as well.

Comment 1

[Robert Strong (they/them - no direct email)]

It may also make sense to have a safe mode option to restore the default set as is available for localstore.rdf

Comment 2

[u88484]

*** Bug 349661 has been marked as a duplicate of this bug. ***

Comment 3

[Dave Townsend [:mossop]]

At http://mxr.mozilla.org/mozilla-central/source/layout/style/nsLayoutStylesheetCache.cpp#179 bail out early if nsIXULAppInfo says we are in safe mode probably.

Comment 4

[Benjamin Smedberg]

Not going to block on this, but I'll take it since it's pretty trivial.

Comment 5

[Nochum Sossonko [:Natch]]

Since all the docs portray safe mode as a "safe place" where a user can assume that anything that goes wrong here must be a firefox issue *and* from a security POV this is supposed to be somewhat of a safe-haven (which user[Content|Chrome].css ensure is not true), perhaps this should block 1.9.2?

Comment 6

[Nochum Sossonko [:Natch]]

Attachment: Like so?

Benjamin, I hope you don't mind me taking this, it is pretty simple indeed!

Comment 7

[Benjamin Smedberg]

Comment on attachment 377953 [details] [diff] [review]
Like so?

I'm not a peer of this code, but this looks fine to me. Asking for sr from a proper owner.

Comment 8

[Johnny Stenback (:jst)]

Comment on attachment 377953 [details] [diff] [review]
Like so?

I'm not really familiar with the stylesheet code either, but dbaron is.

Comment 9

[Boris Zbarsky [:bzbarsky]]

Comment on attachment 377953 [details] [diff] [review]
Like so?

Yeah, this looks fine.

Comment 10

[Nochum Sossonko [:Natch]]

thanks, y'all!

Comment 11

[Nochum Sossonko [:Natch]]

Can someone check this in for me? Should still apply (I have it applied locally on tip as of yesterday).

Comment 12

[Dão Gottwald [:dao]]

http://hg.mozilla.org/mozilla-central/rev/4485b488ce96

Comment 13

[Nochum Sossonko [:Natch]]

Worth a user/dev doc? Can't really be tested afaik, litmus test would be nice.

Comment 14

[Henrik Skupin [:whimboo][⌚️UTC+2]]

(In reply to comment #13)
> Worth a user/dev doc? Can't really be tested afaik, litmus test would be nice.

If you are interested I can guide you through Mozmill. It sounds like a nice restart test.