Multi-monitor - Maximized Firefox windows cast shadows on adjacent monitors

[Captain Chaos]

I don't know if this is a Firefox bug or a Compiz one. Feel free to reassign. What happens is that maximized Firefox windows with the keyboard focus cast shadows on windows on adjacent monitors on a multimonitor setup. It appears to happen only with Firefox, I will report if I see it happen with other programs.

This is reported as fixed in bug #928807, so perhaps it wasn't (fully), or it has regressed. Or maybe this is an unrelated problem. I'm seeing it in Ubuntu 14.04 64-bit on a laptop with an NVidia GeForce GTX 765M.

Attached is a screenshot showing the problem. I have three monitors, with the launcher placed on the middle one. The editor window is on my third monitor and as you can see Firefox is casting a shadow on it.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: compiz 1:0.9.11+14.04.20140423-0ubuntu1
ProcVersionSignature: Ubuntu 3.13.0-29.53-generic 3.13.11.2
Uname: Linux 3.13.0-29-generic x86_64
.tmp.unity.support.test.0:

ApportVersion: 2.14.1-0ubuntu3.2
Architecture: amd64
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CompositorRunning: compiz
CompositorUnredirectDriverBlacklist: '(nouveau|Intel).*Mesa 8.0'
CompositorUnredirectFSW: true
CurrentDesktop: Unity
Date: Sun Jun 8 17:24:34 2014
DistUpgraded: 2014-05-17 01:18:49,586 DEBUG enabling apt cron job
DistroCodename: trusty
DistroVariant: ubuntu
GraphicsCard:
 Intel Corporation 4th Gen Core Processor Integrated Graphics Controller [8086:0416] (rev 06) (prog-if 00 [VGA controller])
   Subsystem: CLEVO/KAPOK Computer Device [1558:3537]
   Subsystem: CLEVO/KAPOK Computer Device [1558:3537]
InstallationDate: Installed on 2013-07-31 (311 days ago)
InstallationMedia: Ubuntu 13.04 "Raring Ringtail" - Release amd64 (20130424)
MachineType: Notebook W350STQ/W370ST
PackageArchitecture: all
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-29-generic root=UUID=6ca812df-7fe0-490d-af8c-6cc9758c0d89 ro "acpi_osi=!Windows 2012" acpi_backlight=vendor quiet splash vt.handoff=7
SourcePackage: compiz
UpgradeStatus: Upgraded to trusty on 2014-05-16 (22 days ago)
dmi.bios.date: 06/14/2013
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 4.6.5
dmi.board.asset.tag: Tag 12345
dmi.board.name: W350STQ/W370ST
dmi.board.vendor: Notebook
dmi.board.version: Not Applicable
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 9
dmi.chassis.vendor: Notebook
dmi.chassis.version: N/A
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr4.6.5:bd06/14/2013:svnNotebook:pnW350STQ/W370ST:pvrNotApplicable:rvnNotebook:rnW350STQ/W370ST:rvrNotApplicable:cvnNotebook:ct9:cvrN/A:
dmi.product.name: W350STQ/W370ST
dmi.product.version: Not Applicable
dmi.sys.vendor: Notebook
version.compiz: compiz 1:0.9.11+14.04.20140423-0ubuntu1
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.52-1
version.libgl1-mesa-dri: libgl1-mesa-dri 10.1.3-0ubuntu0.1
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 10.1.3-0ubuntu0.1
version.xserver-xorg-core: xserver-xorg-core 2:1.15.1-0ubuntu2
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.8.2-1ubuntu2
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.3.0-1ubuntu3.1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.910-0ubuntu1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.10-1ubuntu2
xserver.bootTime: Sun Jun 8 15:54:00 2014
xserver.configfile: default
xserver.errors:

xserver.logfile: /var/log/Xorg.0.log
xserver.outputs:
 product id 19088
 vendor GSM
xserver.version: 2:1.15.1-0ubuntu2

[Thorbjørn Ravn Andersen (SB) (tra-spam)]

I see a similar problem. Eclipse on monitor 1 is maximized and the window shadow bleeds over to monitor 2. The two monitors have been placed "next to" each other so the bleeding happens where the two monitors are logically joined.