Bug#689817: iceweasel: text rendering in lines of shown pages and tabs is unreadable, looks "pixelized"

[Uli Wannek]

Package: iceweasel
Version: 10.0.7esr-2
Severity: normal

Dear Maintainer,

Browsing iceweasel gives sometimes partly unreadable text.
Text looks scrambled, pixelized or bulky.
Not only he content of the web pages, but also the tab header and sometimes 
iceweasel's  menue.

In 2009 there has been a problem with libcairo (Debian bug #666468) but now restoring the old 
libcairo does not help anymore. So i believ it's a new bug. (But the output is the same,
for comparison)

Switching off hardware acceleration in iceweasel does not help, either.

But i could solve the issue by enabling shadow framebuffer in nouveau's xorg.conf:
  Section "Device"
    Option "ShadowFB" "true"

The error is only visible in iceweasel. All other programs behave normally, that means: look good.


   * What led up to the situation?
       Browsing web-pages. At first they look normal. Suddenly, after some seconds
       parts of text become unreadable.
       It looks scrambeled, pixelized, as a block. 
       Hoover with the mouse or moving the iceweasel window out of the screen and back 
       restores readability for some time.

   * What exactly did you do (or not do) that was effective (or
     ineffective)?
       Start iceweasel, load (any) web page. Scroll.

   * What was the outcome of this action?
       Partly unreadable text.

   * What outcome did you expect instead?
       Normally rendered readable text



-- Package-specific info:

-- Extensions information
Name: Default theme
Location: /usr/lib/iceweasel/extensions/{972ce4c6-7e08-4474-a285-3208198ce6fd}
Package: iceweasel
Status: enabled

Name: Deutsch (DE) Language Pack locale
Location: /usr/lib/iceweasel/extensions/langpack-de at iceweasel.mozilla.org.xpi
Package: iceweasel-l10n-de
Status: enabled

Name: English (GB) Language Pack locale
Location: /usr/lib/iceweasel/extensions/langpack-en-GB at iceweasel.mozilla.org.xpi
Package: iceweasel-l10n-en-gb
Status: enabled

Name: Italiano (IT) Language Pack locale
Location: /usr/lib/iceweasel/extensions/langpack-it at iceweasel.mozilla.org.xpi
Package: iceweasel-l10n-it
Status: enabled

Name: Polski Language Pack locale
Location: /usr/lib/iceweasel/extensions/langpack-pl at iceweasel.mozilla.org.xpi
Package: iceweasel-l10n-pl
Status: enabled

Name: Português Brasileiro Language Pack locale
Location: /usr/lib/iceweasel/extensions/langpack-pt-BR at iceweasel.mozilla.org.xpi
Package: iceweasel-l10n-pt-br
Status: enabled

-- Plugins information
Name: Skype Buttons for Kopete
Location: /usr/lib/mozilla/plugins/skypebuttons.so
Package: kopete
Status: enabled


-- Addons package information
ii  iceweasel      10.0.7esr-2  amd64        Web browser based on Firefox
ii  iceweasel-l10n 1:10.0.7esr- all          German language package for Icewe
ii  iceweasel-l10n 1:10.0.7esr- all          English (United Kingdom) language
ii  iceweasel-l10n 1:10.0.7esr- all          Italian language package for Icew
ii  iceweasel-l10n 1:10.0.7esr- all          Polish language package for Icewe
ii  iceweasel-l10n 1:10.0.7esr- all          Portuguese (Brazil) language pack
ii  kopete         4:4.8.4-1+b1 amd64        instant messaging and chat applic

-- System Information:
Debian Release: wheezy/sid
  APT prefers unstable
  APT policy: (500, 'unstable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 3.6-0.towo-siduction-amd64 (SMP w/8 CPU cores; PREEMPT)
Locale: LANG=de_DE.utf8, LC_CTYPE=de_DE.utf8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash

Versions of packages iceweasel depends on:
ii  debianutils         4.3.4
ii  fontconfig          2.9.0-7
ii  libc6               2.13-35
ii  libgdk-pixbuf2.0-0  2.26.1-1
ii  libglib2.0-0        2.33.12+really2.32.4-1
ii  libgtk2.0-0         2.24.10-2
ii  libnspr4            2:4.9.2-1
ii  libnspr4-0d         2:4.9.2-1
ii  libsqlite3-0        3.7.14-1
ii  libstdc++6          4.7.2-2
ii  procps              1:3.3.3-2
ii  xulrunner-10.0      10.0.7esr-2

iceweasel recommends no packages.

Versions of packages iceweasel suggests:
pn  fonts-stix | otf-stix  <none>
ii  libgssapi-krb5-2       1.10.1+dfsg-2
pn  mozplugger             <none>

Versions of packages xulrunner-10.0 depends on:
ii  libasound2                1.0.25-4
ii  libatk1.0-0               2.4.0-2
ii  libbz2-1.0                1.0.6-4
ii  libc6                     2.13-35
ii  libcairo2                 1.12.2-2
ii  libdbus-1-3               1.6.8-1
ii  libdbus-glib-1-2          0.100-1
ii  libevent-2.0-5            2.0.19-stable-3
ii  libfontconfig1            2.9.0-7
ii  libfreetype6              2.4.9-1
ii  libgcc1                   1:4.7.2-2
ii  libgdk-pixbuf2.0-0        2.26.1-1
ii  libglib2.0-0              2.33.12+really2.32.4-1
ii  libgtk2.0-0               2.24.10-2
ii  libhunspell-1.3-0         1.3.2-4
ii  libjpeg8                  8d-1
ii  libmozjs10d               10.0.7esr-2
ii  libnotify4                0.7.5-1
ii  libnspr4-0d               2:4.9.2-1
ii  libnss3-1d                2:3.13.6-1
ii  libpango1.0-0             1.30.0-1
ii  libpixman-1-0             0.26.0-3
ii  libreadline6              6.2-9
ii  libsqlite3-0              3.7.14-1
ii  libstartup-notification0  0.12-1
ii  libstdc++6                4.7.2-2
ii  libvpx1                   1.1.0-1
ii  libx11-6                  2:1.5.0-1
ii  libxext6                  2:1.3.1-2
ii  libxrender1               1:0.9.7-1
ii  libxt6                    1:1.1.3-1
ii  zlib1g                    1:1.2.7.dfsg-13

Versions of packages xulrunner-10.0 suggests:
ii  libcanberra0  0.28-5
pn  libgnomeui-0  <none>

-- Configuration Files:
/etc/iceweasel/profile/prefs.js changed:
user_pref("intl.accept_languages", "de, en, en-us");


-- no debconf information