Weird font rendering glitch in firefox

Question

Hi all,
When I look at this webpage in Firefox this is what I get:
Notice how every occurrence of "ff" and "ft" look weird.
This is Mozilla Firefox 13.0.1.
System & Xorg info:
knarf ~ > Xorg -version
X.Org X Server 1.12.3
Release Date: 2012-07-09
X Protocol Version 11, Revision 0
Build Operating System: Linux 3.4.4-3-ARCH x86_64
Current Operating System: Linux paf 3.4.4-3-ARCH #1 SMP PREEMPT Tue Jul 3 14:36:44 UTC 2012 x86_64
Kernel command line: root=/dev/sda3 ro
Build Date: 09 July 2012 03:59:39PM
Current version of pixman: 0.26.2
Before reporting problems, check http://wiki.x.org
to make sure that you have the latest version.
Font-related installed packages:
knarf ~ > pacman -Qs ttf
local/ttf-dejavu 2.33-3
Font family based on the Bitstream Vera Fonts with a wider range of characters
local/ttf-freefont 20120503-1
Set of free outline fonts covering the Unicode character set
knarf ~ > pacman -Qs font
local/fontconfig 2.8.0-2
A library for configuring and customizing font access
local/fontforge 20120119-1
Outline and bitmap font editor
local/fontsproto 2.1.2-1
X11 font extension wire protocol
local/freetype2 2.4.10-1
TrueType font rendering library
local/libfontenc 1.1.1-1
X11 font encoding library
local/libxfont 1.4.5-1
X11 font rasterisation library
local/libxft 2.3.1-1
FreeType-based font drawing library for X
local/ttf-dejavu 2.33-3
Font family based on the Bitstream Vera Fonts with a wider range of characters
local/ttf-freefont 20120503-1
Set of free outline fonts covering the Unicode character set
local/xorg-bdftopcf 1.0.3-2 (xorg xorg-apps)
Convert X font from Bitmap Distribution Format to Portable Compiled Format
local/xorg-font-util 1.3.0-1 (xorg-fonts xorg)
X.Org font utilities
local/xorg-font-utils 7.6-3
Transitional package depending on xorg font utilities
local/xorg-fonts-alias 1.0.2-2
X.org font alias files
local/xorg-fonts-encodings 1.0.4-3 (xorg-fonts xorg)
X.org font encoding files
local/xorg-fonts-misc 1.0.1-2
X.org misc fonts
local/xorg-mkfontdir 1.0.7-1 (xorg xorg-apps)
Create an index of X font files in a directory
local/xorg-mkfontscale 1.1.0-1 (xorg-apps xorg)
Create an index of scalable font files for X

Answer 1

ewaller wrote:It is interesting to note those combinations are typographic ligatures.  I'll bet two credits that is not a coincidence.
I bet my credits the fault is within the Calibri font.
You can do a font substitution for Calibri.  I made the change for all users.  Before anyone does this they might check, from the command line, what font is being used for Calibri:  'fc-match Calibri'
In /etc/fonts/conf.avail/ I added the file, 39-no-calibri.conf:
<?xml version="1.0"?>
<!DOCTYPE fontconfig SYSTEM "fonts.dtd">
<fontconfig>
<!-- Replace Calibri with generic fonts
bad ligatures in Calibri -->
<match target="pattern" name="family">
<test name="family" qual="any">
<string>Calibri</string>
</test>
<edit mode="assign" name="family">
<string>Arial</string>
<string>Liberation Sans</string>
<string>sans-serif</string>
</edit>
</match>
</fontconfig>
Then I symlinked to it from /etc/fonts/conf.d/:
# pwd
/etc/fonts/conf.d
# ln -s /etc/fonts/conf.avail/39-no-calibri.conf
Finally, I updated the font cache with 'fc-cache -vf'.