[Firefox] thin vertical/horizontal lines appear when the web-page is zoomed

[Miroslav Hadzhiev]

Binary package hint: firefox-3.5

Thin vertical or horizontal lines appear when the web-page is "zoomed-in".

My video card is ati Mobility X1600 256 mb gddr3 (using default configuration for X.Org server and the open-sourced 'radeon' driver).

ProblemType: Bug
Architecture: amd64
Date: Thu Dec 24 12:29:41 2009
DistroRelease: Ubuntu 9.10
InstallationMedia: Ubuntu 9.10 "Karmic Koala" - Release amd64 (20091027)
Package: firefox-3.5 3.5.6+nobinonly-0ubuntu0.9.10.1
ProcEnviron:
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.31-16.53-generic
SourcePackage: firefox-3.5
Uname: Linux 2.6.31-16-generic x86_64
XsessionErrors:
 (gnome-settings-daemon:1752): GLib-CRITICAL **: g_propagate_error: assertion `src != NULL' failed
 (gnome-settings-daemon:1752): GLib-CRITICAL **: g_propagate_error: assertion `src != NULL' failed
 (polkit-gnome-authentication-agent-1:1845): GLib-CRITICAL **: g_once_init_leave: assertion `initialization_value != 0' failed
 (nautilus:1791): Eel-CRITICAL **: eel_preferences_get_boolean: assertion `preferences_is_initialized ()' failed
 (firefox:2552): GLib-WARNING **: g_set_prgname() called multiple times

[Miroslav Hadzhiev (xtigyro)]

The interesting thing is that when 'particular' level of zooming is reached, the lines disappeared and zooming-in more does not cause reappearing of these vertical/horizontal lines.

[Miroslav Hadzhiev (xtigyro)]

As you can see, here there are no lines.

[Miroslav Hadzhiev (xtigyro)]

And if I continue to hit 'ctrl and +', there are no more any lines (even if i reach the maximum level of zooming in).

[Miroslav Hadzhiev (xtigyro)]

This is still an issue in Lucid Lynx.

The nice part of the bug is that I found a work-around. If Firefox is compiled with the smooth scaling of images option turned on, the bug does not occur. So if this bug https://bugs.launchpad.net/ubuntu/+source/cairo/+bug/217908?comments=all is solved, the problem will be solved, too.