Xorg crashed with SIGABRT in RRSetChanged()

[Per Lycke]

Don't really know lol

ProblemType: Crash
DistroRelease: Ubuntu 15.04
Package: xserver-xorg-core 2:1.16.2.901-1ubuntu4
Uname: Linux 3.19.1-031901-generic x86_64
.tmp.unity.support.test.0:

ApportVersion: 2.16.2-0ubuntu2
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
CrashCounter: 1
Date: Thu Mar 12 17:56:34 2015
DistUpgraded: 2015-03-12 17:55:45,089 DEBUG enabling apt cron job
DistroCodename: vivid
DistroVariant: ubuntu
ExecutablePath: /usr/bin/Xorg
ExtraDebuggingInterest: No
GraphicsCard:
 Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller [8086:0116] (rev 09) (prog-if 00 [VGA controller])
   Subsystem: Apple Inc. Device [106b:00dc]
 Advanced Micro Devices, Inc. [AMD/ATI] Seymour [Radeon HD 6400M/7400M Series] [1002:6760] (prog-if 00 [VGA controller])
   Subsystem: Apple Inc. Device [106b:00e1]
InstallationDate: Installed on 2014-12-02 (99 days ago)
InstallationMedia: Ubuntu 14.10 "Utopic Unicorn" - Release amd64 (20141022.1)
MachineType: Apple Inc. MacBookPro8,2
ProcCmdline: /usr/bin/X -core :0 -seat seat0 -auth /var/run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch
ProcEnviron:

ProcKernelCmdLine: \boot\vmlinuz-3.19.1-031901-generic ro root=UUID=7d4c6e12-8bbb-48a9-8469-e53f7cf89649 initrd=boot\initrd.img-3.19.1-031901-generic
Signal: 6
SourcePackage: xorg-server
StacktraceTop:
 RRSetChanged ()
 RRScreenSetSizeRange ()
 xf86RandR12CreateScreenResources ()
 ?? ()
 ?? ()
Title: Xorg crashed with SIGABRT in RRSetChanged()
UpgradeStatus: Upgraded to vivid on 2015-03-12 (0 days ago)
UserGroups:

dmi.bios.date: 01/24/12
dmi.bios.vendor: Apple Inc.
dmi.bios.version: MBP81.88Z.0047.B27.1201241646
dmi.board.asset.tag: Base Board Asset Tag#
dmi.board.name: Mac-94245A3940C91C80
dmi.board.vendor: Apple Inc.
dmi.board.version: MacBookPro8,2
dmi.chassis.type: 10
dmi.chassis.vendor: Apple Inc.
dmi.chassis.version: Mac-94245A3940C91C80
dmi.modalias: dmi:bvnAppleInc.:bvrMBP81.88Z.0047.B27.1201241646:bd01/24/12:svnAppleInc.:pnMacBookPro8,2:pvr1.0:rvnAppleInc.:rnMac-94245A3940C91C80:rvrMacBookPro8,2:cvnAppleInc.:ct10:cvrMac-94245A3940C91C80:
dmi.product.name: MacBookPro8,2
dmi.product.version: 1.0
dmi.sys.vendor: Apple Inc.
version.compiz: compiz 1:0.9.12.1+15.04.20150303-0ubuntu1
version.ia32-libs: ia32-libs 20090808ubuntu36
version.libdrm2: libdrm2 2.4.59-0ubuntu1
version.libgl1-mesa-dri: libgl1-mesa-dri 10.5.0-0ubuntu1
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 10.5.0-0ubuntu1
version.xserver-xorg-core: xserver-xorg-core 2:1.16.2.901-1ubuntu4
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.9.0-1ubuntu2
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.4.0-2ubuntu2
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917-1~exp1ubuntu2
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.11-1ubuntu2
xserver.bootTime: Thu Mar 12 17:59:57 2015
xserver.configfile: default
xserver.errors:

xserver.logfile: /var/log/Xorg.0.log
xserver.version: 2:1.16.2.901-1ubuntu4
xserver.video_driver: radeon

[Apport retracing service (apport)]

Thank you for taking the time to report this crash and helping to make this software better. This particular crash has already been reported and is a duplicate of bug #1249551, so is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Please continue to report any other bugs you may find.