secondary monitor with no launcher shows launcher mask in window spread

[Robert Hollencamp]

see the attached screenshot

Steps to reproduce:
 * have two monitors
 * have the launcher only show on one monitor
 * enter window spread (<Super>+W)

Expected results:
 * on the monitor without the launcher, no mask is shown around where the launcher would have been

Actual Results
 * on the monitor without the launcher, a mask is shown around where the launcher would have been

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: unity 7.4.0+16.04.20160906-0ubuntu1
ProcVersionSignature: Ubuntu 4.4.0-47.68-generic 4.4.24
Uname: Linux 4.4.0-47-generic x86_64
.tmp.unity_support_test.0:

ApportVersion: 2.20.1-0ubuntu2.1
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: Fri Nov 11 14:05:34 2016
DistUpgraded: Fresh install
DistroCodename: xenial
DistroVariant: ubuntu
GraphicsCard:
 Intel Corporation Crystal Well Integrated Graphics Controller [8086:0d26] (rev 08) (prog-if 00 [VGA controller])
   Subsystem: Apple Inc. Crystal Well Integrated Graphics Controller [106b:0148]
 Advanced Micro Devices, Inc. [AMD/ATI] Venus XT [Radeon HD 8870M / R9 M270X/M370X] [1002:6821] (rev 83) (prog-if 00 [VGA controller])
   Subsystem: Apple Inc. Radeon R9 M370X Mac Edition [106b:0149]
InstallationDate: Installed on 2016-11-03 (8 days ago)
InstallationMedia: Ubuntu 16.04.1 LTS "Xenial Xerus" - Release amd64 (20160719)
MachineType: Apple Inc. MacBookPro11,5
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.4.0-47-generic.efi.signed root=UUID=cb2b619c-d827-4c4c-aafe-819321516a87 ro quiet splash vt.handoff=7
SourcePackage: unity
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 02/15/2016
dmi.bios.vendor: Apple Inc.
dmi.bios.version: MBP114.88Z.0172.B09.1602151732
dmi.board.name: Mac-06F11F11946D27C5
dmi.board.vendor: Apple Inc.
dmi.board.version: MacBookPro11,5
dmi.chassis.type: 9
dmi.chassis.vendor: Apple Inc.
dmi.chassis.version: Mac-06F11F11946D27C5
dmi.modalias: dmi:bvnAppleInc.:bvrMBP114.88Z.0172.B09.1602151732:bd02/15/2016:svnAppleInc.:pnMacBookPro11,5:pvr1.0:rvnAppleInc.:rnMac-06F11F11946D27C5:rvrMacBookPro11,5:cvnAppleInc.:ct9:cvrMac-06F11F11946D27C5:
dmi.product.name: MacBookPro11,5
dmi.product.version: 1.0
dmi.sys.vendor: Apple Inc.
version.compiz: compiz 1:0.9.12.2+16.04.20160823-0ubuntu1
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.67-1ubuntu0.16.04.2
version.libgl1-mesa-dri: libgl1-mesa-dri 11.2.0-1ubuntu2.2
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 11.2.0-1ubuntu2.2
version.xserver-xorg-core: xserver-xorg-core 2:1.18.4-0ubuntu0.1
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.10.1-1ubuntu2
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.7.0-1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20160325-1ubuntu1.1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.12-1build2
xserver.bootTime: Fri Nov 11 13:37:48 2016
xserver.configfile: default
xserver.errors:

xserver.logfile: /var/log/Xorg.0.log
xserver.version: 2:1.18.4-0ubuntu0.1
xserver.video_driver: radeon

[Robert Hollencamp (rhollencamp)]

appears to be a regression introduced in https://bugs.launchpad.net/unity/+bug/1283314/