Opened 7 years ago

Last modified 8 weeks ago

#6065 assigned defect

TBB does strange things to fonts on Windows 7

Reported by: runa Owned by:
Priority: Medium Milestone:
Component: Applications/Tor Browser Version:
Severity: Normal Keywords: tbb-fingerprinting-fonts
Cc: mikeperry, g.koppen@… Actual Points:
Parent ID: Points:
Reviewer: Sponsor:

Description

A user reports the following on our blog:

The default font for the Tor Browser is Times New Roman (size: 16). When using 2.2.35-8, there was no problem rendering web pages with the default font. Starting with 2.2.35-12 (the first upgrade I used after 2.2.35-8), web page fonts were changed and difficult to read on some websites so I changed the default font to Arial (size: 16). Now they're more readable but still it's not the same (specifically, not as large) as when using 2.2.35-8.

Child Tickets

Change History (11)

comment:1 Changed 7 years ago by erinn

Cc: mikeperry added

Mike, is this related to any Firefox patches?

comment:2 Changed 7 years ago by mikeperry

Quite possibly, yes.. Checking git tags reveals that while the font patch was present in 2.2.35-8, we didn't set limits for it until 2.2.35-9.

The good news is that this means the patch is not at fault, just the limits we chose.

The limits are in about:config prefs browser.display.max_font_count and browser.display.max_font_attempts, set at 5 and 10 respectively.

It is odd that this limit might affect the default font, though... Perhaps this is another case of our patches applying not just to the content window, but to the chrome as well (like #4795)?

Action items:
The zeroth thing to find out is a test page that we can clearly witness the behavior.
The first thing to find out is if the user has set any other custom prefs wrt fonts.
The second thing is to find out if raising the limit changes things, and at what point.

comment:3 Changed 7 years ago by mikeperry

Component: Tor bundles/installationFirefox Patch Issues
Status: newneeds_information
Type: taskdefect

I'm going to just go ahead and reassign this to me, but it's unlikely I'll be able to do much without more information.

comment:4 Changed 7 years ago by mikeperry

Owner: changed from erinn to mikeperry
Status: needs_informationassigned

comment:5 Changed 7 years ago by mikeperry

Status: assignedneeds_information

I love the trac ticket change state machine...

comment:6 in reply to:  2 ; Changed 7 years ago by cypherpunks

I've also noticed this. A couple pages you could check are the BBC Iplayer and also on Ixquick, but only after you get search results and then click in the search box again to modify the search terms and suddenly those terms change font. I haven't customized anything font-related.
Replying to mikeperry:

Quite possibly, yes.. Checking git tags reveals that while the font patch was present in 2.2.35-8, we didn't set limits for it until 2.2.35-9.

The good news is that this means the patch is not at fault, just the limits we chose.

The limits are in about:config prefs browser.display.max_font_count and browser.display.max_font_attempts, set at 5 and 10 respectively.

It is odd that this limit might affect the default font, though... Perhaps this is another case of our patches applying not just to the content window, but to the chrome as well (like #4795)?

Action items:
The zeroth thing to find out is a test page that we can clearly witness the behavior.
The first thing to find out is if the user has set any other custom prefs wrt fonts.
The second thing is to find out if raising the limit changes things, and at what point.

comment:7 Changed 7 years ago by gk

Cc: g.koppen@… added

comment:8 in reply to:  6 ; Changed 7 years ago by mikeperry

Replying to cypherpunks:

I've also noticed this. A couple pages you could check are the BBC Iplayer and also on Ixquick, but only after you get search results and then click in the search box again to modify the search terms and suddenly those terms change font. I haven't customized anything font-related.

Do changing the limits in the above prefs fix this issue?

Replying to mikeperry:

It is odd that this limit might affect the default font, though... Perhaps this is another case of our patches applying not just to the content window, but to the chrome as well (like #4795)?

I looked at the patch during rebase for FF13, and it does do the IsChrome() check to not count XUL fonts.

Action items:
The zeroth thing to find out is a test page that we can clearly witness the behavior.
The first thing to find out is if the user has set any other custom prefs wrt fonts.
The second thing is to find out if raising the limit changes things, and at what point.

comment:9 in reply to:  8 Changed 7 years ago by cypherpunks

Replying to mikeperry:

Replying to cypherpunks:

I've also noticed this. A couple pages you could check are the BBC Iplayer and also on Ixquick, but only after you get search results and then click in the search box again to modify the search terms and suddenly those terms change font. I haven't customized anything font-related.

Do changing the limits in the above prefs fix this issue?

I tried them at 10 and 20 and the fonts seem to have stopped changing.

comment:10 Changed 4 years ago by bugzilla

Component: Firefox Patch IssuesTor Browser
Keywords: tbb-fingerprinting-fonts added
Severity: Normal

comment:11 Changed 8 weeks ago by gaba

Owner: mikeperry deleted
Status: needs_informationassigned
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