Global menu drop shadow appears as black bar

[David Lawson]

Running Precise under VirtualBox with two virtual monitors, the global menu drop shadow grows until it's a black bar the height of the menu bar. Focusing a window or taking any other UI actions that would affect that drop shadowing resets it to its proper rendering and then it grows again over the course of about fifteen seconds until it's the same black bar. Oddly, this doesn't show up in screenshots at all, I've resorted to a camera phone picture that shows the problem. This only manifests with multiple virtual monitors, if I drop back to a single monitor, it behaves as it should.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: unity 5.4.0-0ubuntu2
ProcVersionSignature: Ubuntu 3.2.0-18.29-generic 3.2.9
Uname: Linux 3.2.0-18-generic x86_64
.tmp.unity.support.test.0:

ApportVersion: 1.94.1-0ubuntu2
Architecture: amd64
CompizPlugins: [core,bailer,detection,composite,opengl,compiztoolbox,decor,vpswitch,mousepoll,wall,grid,gnomecompat,move,snap,imgpng,place,regex,session,resize,animation,fade,scale,expo,ezoom,workarounds,unityshell]
CompositorRunning: compiz
Date: Mon Mar 12 01:00:39 2012
DistUpgraded: Log time: 2012-03-09 01:08:58.391033
DistroCodename: precise
DistroVariant: ubuntu
DkmsStatus:
 vboxguest, 4.1.8, 3.2.0-18-generic, x86_64: installed
 virtualbox-guest, 4.1.8, 3.2.0-18-generic, x86_64: installed (WARNING! Diff between built and installed module!) (WARNING! Diff between built and installed module!) (WARNING! Diff between built and installed module!)
GraphicsCard: InnoTek Systemberatung GmbH VirtualBox Graphics Adapter [80ee:beef] (prog-if 00 [VGA controller])
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Release amd64 (20111012)
Lsusb:
 Bus 001 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
 Bus 001 Device 002: ID 80ee:0021 VirtualBox USB Tablet
MachineType: innotek GmbH VirtualBox
ProcEnviron:
 TERM=xterm
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.2.0-18-generic root=UUID=e9fc079d-1344-41af-9e74-b855a61d3def ro quiet splash vt.handoff=7
Renderer: Software
SourcePackage: unity
UpgradeStatus: Upgraded to precise on 2012-03-09 (2 days ago)
dmi.bios.date: 12/01/2006
dmi.bios.vendor: innotek GmbH
dmi.bios.version: VirtualBox
dmi.modalias: dmi:bvninnotekGmbH:bvrVirtualBox:bd12/01/2006:svninnotekGmbH:pnVirtualBox:pvr1.2:
dmi.product.name: VirtualBox
dmi.product.version: 1.2
dmi.sys.vendor: innotek GmbH
version.compiz: compiz 1:0.9.7.0~bzr2995-0ubuntu5
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.30-1ubuntu1
version.libgl1-mesa-dri: libgl1-mesa-dri 8.0.1-0ubuntu2
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 8.0.1-0ubuntu2
version.xserver-xorg-core: xserver-xorg-core 2:1.11.4-0ubuntu6
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.6.99.901+git20120126-0ubuntu2
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:6.14.99~git20111219.aacbd629-0ubuntu2
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.17.0-1ubuntu4
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:0.0.16+git20111201+b5534a1-1build2

[Daniel van Vugt (vanvugt)]

This sounds like a duplicate of bug 763579. Only with a different trigger.

I have also reproduced the same shadow overdraw problem when experimenting privately with compiz rendering optimizations. So we have at least 3 different methods of reproducing the bug. I think the root cause is in the Unity panel shadow code.

[Bilal Akhtar (bilalakhtar)]

Can you update to Uniy 5.6 and see if this is an issue? Many bugs regarding the panel shadow were fixed in this update.

[David Lawson (deej)]

Sure. This morning's updates completely hosed my VM, but I'll upgrade when I get it put back together.

[David Lawson (deej)]

unity 5.6 does appear to fix this, I can no longer reproduce it.