Xorg crashed with SIGABRT in FlushAllOutput()

[William Lee]

I think this is to do with Ubuntu seemingly logging out automatically when I'm just innocently browsing around on my computer. At first I thought it was something to do with LightDM, until apport told me to report it. So here I am...
Basically I just browsing on the internet, using my computer normally, until a black screen with an underscore cursor appears in the top left hand corner. Then it brings me onto the login screen. I have no idea what happened

ProblemType: Crash
DistroRelease: Ubuntu 15.10
Package: xserver-xorg-core 2:1.17.2-1ubuntu3
ProcVersionSignature: Ubuntu 3.19.0-15.15-generic 3.19.3
Uname: Linux 3.19.0-15-generic x86_64
.tmp.unity.support.test.0:

ApportVersion: 2.18-0ubuntu7
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
Date: Sat Aug 29 21:42:11 2015
DistUpgraded: 2015-08-06 12:36:17,362 DEBUG enabling apt cron job
DistroCodename: wily
DistroVariant: ubuntu
DkmsStatus: virtualbox, 5.0.2, 3.19.0-15-generic, x86_64: installed
ExecutablePath: /usr/bin/Xorg
ExtraDebuggingInterest: Yes, including running git bisection searches
GraphicsCard:
 Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller [8086:0106] (rev 09) (prog-if 00 [VGA controller])
   Subsystem: Toshiba America Info Systems Device [1179:fc90]
InstallationDate: Installed on 2014-09-06 (359 days ago)
InstallationMedia: Ubuntu 13.10 "Saucy Salamander" - Release amd64 (20131016.1)
MachineType: TOSHIBA SATELLITE C660
ProcCmdline: /usr/bin/X -core :0 -seat seat0 -auth /var/run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch
ProcEnviron:

ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.19.0-15-generic root=UUID=d9749385-e4c3-4834-8d0e-d8547e390f65 ro quiet splash vt.handoff=7
Signal: 6
SourcePackage: xorg-server
StacktraceTop:
 FlushAllOutput ()
 WaitForSomething ()
 ?? ()
 ?? ()
 __libc_start_main (main=0x7f627659e760, argc=11, argv=0x7ffe9bfb89e8, init=<optimised out>, fini=<optimised out>, rtld_fini=<optimised out>, stack_end=0x7ffe9bfb89d8) at libc-start.c:289
Title: Xorg crashed with SIGABRT in FlushAllOutput()
UpgradeStatus: Upgraded to wily on 2015-08-06 (25 days ago)
UserGroups:

dmi.bios.date: 12/15/2011
dmi.bios.vendor: TOSHIBA
dmi.bios.version: 1.50
dmi.board.asset.tag: NULL
dmi.board.name: PWWHA
dmi.board.vendor: TOSHIBA
dmi.board.version: 1.00
dmi.chassis.asset.tag: *
dmi.chassis.type: 10
dmi.chassis.vendor: TOSHIBA
dmi.chassis.version: N/A
dmi.modalias: dmi:bvnTOSHIBA:bvr1.50:bd12/15/2011:svnTOSHIBA:pnSATELLITEC660:pvrPSC1LE-053005EN:rvnTOSHIBA:rnPWWHA:rvr1.00:cvnTOSHIBA:ct10:cvrN/A:
dmi.product.name: SATELLITE C660
dmi.product.version: PSC1LE-053005EN
dmi.sys.vendor: TOSHIBA
version.compiz: compiz 1:0.9.12.1+15.10.20150805-0ubuntu1
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.64-1
version.libgl1-mesa-dri: libgl1-mesa-dri 10.6.3-1ubuntu1
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 10.6.3-1ubuntu1
version.xserver-xorg-core: xserver-xorg-core 2:1.17.2-1ubuntu3
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.9.2-1ubuntu1
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.5.0+git20150819-0ubuntu1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917-1ubuntu1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.11-1ubuntu3
xserver.bootTime: Mon Aug 31 20:21:25 2015
xserver.configfile: default
xserver.errors:

xserver.logfile: /var/log/Xorg.0.log
xserver.outputs:
 product id 732
 vendor LGD
xserver.version: 2:1.17.2-1ubuntu3

[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 #1487438, 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.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.