Bug#741218: iceweasel: Tearing when vertical scrolling (xrender?)

[Chris Bainbridge]

Package: iceweasel
Version: 24.3.0esr-1
Severity: important

Dear Maintainer,

On a laptop with Intel (Ivy Bridge) integrated graphics and XFCE I get
tearing when vertical scrolling web pages in Iceweasel. Searching the
web I came across:

https://blogs.fsfe.org/the_unconventional/2013/07/04/fixing-iceweasels-tearing-and-rendering-problems/

Which suggests that xrender is to blame, and that iceweasel should be
(should have been) configured to use OpenGL rendering instead. The
suggestions there do seem to fix the tearing.

Shouldn't OpenGL rendering be the default? Or is there some setting in
xrender that could be changed to eliminate tearing?

New users of iceweasel shouldn't be expected to manually
fiddle around with rendering config options to get rid of tearing, it
should just work.

-- Package-specific info:

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

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

-- Plugins information

-- Addons package information
ii  iceweasel      24.3.0esr-1  amd64        Web browser based on Firefox
ii  iceweasel-l10n 1:24.3.0esr- all          English (United Kingdom) language

-- System Information:
Debian Release: jessie/sid
  APT prefers testing-updates
  APT policy: (500, 'testing-updates'), (500, 'testing')
Architecture: amd64 (x86_64)

Kernel: Linux 3.12-1-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_GB.utf8, LC_CTYPE=en_GB.utf8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash

Versions of packages iceweasel depends on:
ii  debianutils         4.4
ii  fontconfig          2.11.0-2
ii  libc6               2.18-4
ii  libgdk-pixbuf2.0-0  2.30.5-1
ii  libglib2.0-0        2.38.2-5
ii  libgtk2.0-0         2.24.22-1
ii  libnspr4            2:4.10.3-1
ii  libsqlite3-0        3.8.3.1-1
ii  libstdc++6          4.8.2-16
ii  procps              1:3.3.9-2
ii  xulrunner-24.0      24.3.0esr-1

iceweasel recommends no packages.

Versions of packages iceweasel suggests:
pn  fonts-mathjax          <none>
pn  fonts-oflb-asana-math  <none>
ii  fonts-stix [otf-stix]  1.1.0-1
ii  libgssapi-krb5-2       1.12+dfsg-2
pn  mozplugger             <none>

Versions of packages xulrunner-24.0 depends on:
ii  libasound2                1.0.27.2-3
ii  libatk1.0-0               2.10.0-2
ii  libbz2-1.0                1.0.6-5
ii  libc6                     2.18-4
ii  libcairo2                 1.12.16-2
ii  libdbus-1-3               1.8.0-1
ii  libdbus-glib-1-2          0.102-1
ii  libevent-2.0-5            2.0.21-stable-1
ii  libfontconfig1            2.11.0-2
ii  libfreetype6              2.5.2-1
ii  libgcc1                   1:4.8.2-16
ii  libgdk-pixbuf2.0-0        2.30.5-1
ii  libglib2.0-0              2.38.2-5
ii  libgtk2.0-0               2.24.22-1
ii  libhunspell-1.3-0         1.3.2-6
ii  libmozjs24d               24.3.0esr-1
ii  libnspr4                  2:4.10.3-1
ii  libnss3                   2:3.15.4-2
ii  libpango-1.0-0            1.36.2-2
ii  libsqlite3-0              3.8.3.1-1
ii  libstartup-notification0  0.12-3
ii  libstdc++6                4.8.2-16
ii  libvpx1                   1.3.0-2
ii  libx11-6                  2:1.6.2-1
ii  libxext6                  2:1.3.2-1
ii  libxrender1               1:0.9.8-1
ii  libxt6                    1:1.1.4-1
ii  zlib1g                    1:1.2.8.dfsg-1

Versions of packages xulrunner-24.0 suggests:
ii  libcanberra0  0.30-2
ii  libgnomeui-0  2.24.5-3

-- no debconf information