Xorg crash when displays added during sleep

[Riley McDowell]

I have a laptop and docking station with 2 displays attached. I can trigger a crash of the Xorg desktop by the following series of steps.

Actual Behavior:

1. While the laptop is on the dock, put it to sleep
2. Pick up the laptop from the dock
3. Wake up the laptop while undocked
4. Use xrandr commands to adjust the laptops screen so it is the primary display
5. Put the laptop back to sleep
6. Re-dock the laptop
7. Wake up the laptop on the dock
8. Observe that Xorg has crashed, desktop state is lost, and the laptop has returned to the login screen.

Expected Behavior:

These is no combination of docking, sleeping, or xrandr display commands that can crash my X session and drop my laptop back to the login screen.

Notes on Timing of this Issue:
I've been living with this issue for many months, but it's only recently that I've realized that I can trigger it 100% of the time by running xrandr commands while undocked, then re-docking. This pattern is common if you use your laptop for work, taking it back and forth between the dock and various meeting rooms, then back to the dock again.

Information:
Ubuntu Release: Ubuntu 18.04.1 LTS
Nvidia Driver: 390.77-0ubuntu0.18.04.1
xserver-xorg: 1:7.7+19ubuntu7.1

ProblemType: Crash
DistroRelease: Ubuntu 18.04
Package: xserver-xorg-core 2:1.19.6-1ubuntu4.2
ProcVersionSignature: Ubuntu 4.15.0-39.42-generic 4.15.18
Uname: Linux 4.15.0-39-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
.proc.driver.nvidia.gpus.0000.01.00.0: Error: [Errno 21] Is a directory: '/proc/driver/nvidia/gpus/0000:01:00.0'
.proc.driver.nvidia.registry: Binary: ""
.proc.driver.nvidia.version:
 NVRM version: NVIDIA UNIX x86_64 Kernel Module 390.77 Tue Jul 10 18:28:52 PDT 2018
 GCC version: gcc version 7.3.0 (Ubuntu 7.3.0-27ubuntu1~18.04)
.tmp.unity_support_test.0:

ApportVersion: 2.20.9-0ubuntu7.5
Architecture: amd64
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CompositorRunning: None
Date: Thu Nov 29 10:05:46 2018
DistUpgraded: 2018-10-17 09:43:06,225 DEBUG Running PostInstallScript: './xorg_fix_proprietary.py'
DistroCodename: bionic
DistroVariant: ubuntu
DkmsStatus:
 nvidia, 390.77, 4.15.0-38-generic, x86_64: installed
 nvidia, 390.77, 4.15.0-39-generic, x86_64: installed
EcryptfsInUse: Yes
ExecutablePath: /usr/lib/xorg/Xorg
ExecutableTimestamp: 1540480712
GraphicsCard:
 Intel Corporation HD Graphics 530 [8086:191b] (rev 06) (prog-if 00 [VGA controller])
   Subsystem: Dell HD Graphics 530 [1028:07b0]
 NVIDIA Corporation GM206GLM [Quadro M2200 Mobile] [10de:1436] (rev a1) (prog-if 00 [VGA controller])
   Subsystem: Dell GM206GLM [Quadro M2200 Mobile] [1028:07b0]
InstallationDate: Installed on 2018-03-12 (261 days ago)
InstallationMedia: Ubuntu 16.04.4 LTS "Xenial Xerus" - Release amd64 (20180228)
MachineType: Dell Inc. Precision 7520
ProcCmdline: /usr/lib/xorg/Xorg vt2 -displayfd 3 -auth /run/user/1000/gdm/Xauthority -background none -noreset -keeptty -verbose 7 -core
ProcCwd: /home/riley
ProcEnviron:

ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.15.0-39-generic root=UUID=87df30cd-49ea-4422-8156-c73c22783751 ro quiet splash vt.handoff=1
Signal: 6
SourcePackage: nvidia-graphics-drivers
StacktraceTop:
 ()
 ()
 ()
 xf86VTEnter ()
 ()
Title: Xorg crashed with SIGABRT
UpgradeStatus: Upgraded to bionic on 2018-10-17 (43 days ago)
UserGroups: adm cdrom dip docker lpadmin plugdev redis sambashare sudo tty vboxusers
dmi.bios.date: 09/07/2017
dmi.bios.vendor: Dell Inc.
dmi.bios.version: 1.7.1
dmi.board.name: 0P707G
dmi.board.vendor: Dell Inc.
dmi.board.version: A00
dmi.chassis.type: 10
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvr1.7.1:bd09/07/2017:svnDellInc.:pnPrecision7520:pvr:rvnDellInc.:rn0P707G:rvrA00:cvnDellInc.:ct10:cvr:
dmi.product.family: Precision
dmi.product.name: Precision 7520
dmi.sys.vendor: Dell Inc.
version.compiz: compiz 1:0.9.13.1+18.04.20180302-0ubuntu1
version.libdrm2: libdrm2 2.4.91-2
version.libgl1-mesa-dri: libgl1-mesa-dri 18.0.5-0ubuntu0~18.04.1
version.libgl1-mesa-glx: libgl1-mesa-glx 18.0.5-0ubuntu0~18.04.1
version.nvidia-graphics-drivers: nvidia-graphics-drivers-* N/A
version.xserver-xorg-core: xserver-xorg-core 2:1.19.6-1ubuntu4.2
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.10.5-1ubuntu1
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:18.0.1-1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20171229-1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.15-2

[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 #1787332, 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.