simple-scan crashed with SIGSEGV

[Jean-Baptiste Lallement]

Test Case:
1. Start simple-scan twice from the command line.

Actual result
This crash

Expected result
Second time does nothing or brings the simple scan window to the front.

ProblemType: Crash
DistroRelease: Ubuntu 18.04
Package: simple-scan 3.26.3-0ubuntu1
ProcVersionSignature: Ubuntu 4.13.0-32.35-generic 4.13.13
Uname: Linux 4.13.0-32-generic x86_64
ApportVersion: 2.20.8-0ubuntu8
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Thu Feb 8 08:11:02 2018
ExecutablePath: /usr/bin/simple-scan
InstallationDate: Installed on 2013-09-03 (1618 days ago)
InstallationMedia: Ubuntu 13.10 "Saucy Salamander" - Alpha amd64 (20130902)
MachineType: ASUSTeK COMPUTER INC. UX32VD
ProcCmdline: simple-scan
ProcEnviron:
 LANG=fr_FR.UTF-8
 TERM=xterm-256color
 SHELL=/bin/bash
 XDG_RUNTIME_DIR=<set>
 PATH=(custom, user)
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.13.0-32-generic root=UUID=1004226d-a9db-46c7-bd28-eca0806c12f2 ro pcie_aspm=force drm.vblankoffdelay=1 i915.semaphores=1 init=/lib/systemd/systemd-bootchart
SegvAnalysis:
 Segfault happened at: 0x7fd8e967369a: mov 0x10(%rax),%edx
 PC (0x7fd8e967369a) ok
 source "0x10(%rax)" (0x00000010) not located in a known VMA region (needed readable region)!
 destination "%edx" ok
 Stack memory exhausted (SP below stack segment)
SegvReason: reading NULL VMA
Signal: 11
SimpleScanLog: [+0,00s] DEBUG: simple-scan.vala:637: Starting Simple Scan 3.26.3, PID=6386
SourcePackage: simple-scan
StacktraceTop:
 () at /usr/lib/x86_64-linux-gnu/sane/libsane-avision.so.1
 sane_avision_get_devices () at /usr/lib/x86_64-linux-gnu/sane/libsane-avision.so.1
 sane_dll_get_devices () at /usr/lib/x86_64-linux-gnu/libsane.so.1
 ()
 g_thread_proxy (data=0x55fefcab1a30) at ../../../../glib/gthread.c:784
Title: simple-scan crashed with SIGSEGV
UpgradeStatus: Upgraded to bionic on 2018-01-26 (12 days ago)
UserGroups: adm autopilot cdrom dip docker libvirt libvirtd lpadmin lxd plugdev sambashare stapdev stapsys stapusr sudo
dmi.bios.date: 01/29/2013
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: UX32VD.214
dmi.board.asset.tag: ATN12345678901234567
dmi.board.name: UX32VD
dmi.board.vendor: ASUSTeK COMPUTER INC.
dmi.board.version: 1.0
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 10
dmi.chassis.vendor: ASUSTeK COMPUTER INC.
dmi.chassis.version: 1.0
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrUX32VD.214:bd01/29/2013:svnASUSTeKCOMPUTERINC.:pnUX32VD:pvr1.0:rvnASUSTeKCOMPUTERINC.:rnUX32VD:rvr1.0:cvnASUSTeKCOMPUTERINC.:ct10:cvr1.0:
dmi.product.family: UX
dmi.product.name: UX32VD
dmi.product.version: 1.0
dmi.sys.vendor: ASUSTeK COMPUTER INC.