Comment 0 for bug 1790525

Problem is occurring if dual monitor is used. Second monitor is repeatingly blank and activated again. At the bottom it probably contains the upper part of the first monitor. I had the same problem at 18.04 when using gdm3 without wayland during logon.

ProblemType: Crash
DistroRelease: Ubuntu 18.10
Package: gnome-shell 3.29.90-2ubuntu1
ProcVersionSignature: Ubuntu 4.17.0-9.10-generic 4.17.17
Uname: Linux 4.17.0-9-generic i686
ApportVersion: 2.20.10-0ubuntu9
Architecture: i386
AssertionMessage: double free or corruption (fasttop)
CurrentDesktop: ubuntu:GNOME
Date: Mon Sep 3 21:02:58 2018
DisplayManager: gdm3
ExecutablePath: /usr/bin/gnome-shell
GsettingsChanges: b'org.gnome.desktop.interface' b'gtk-im-module' b"'gtk-im-context-simple'"
ProcCmdline: /usr/bin/gnome-shell
ProcEnviron:
 LANGUAGE=en_US:en
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
Signal: 6
SourcePackage: gnome-shell
StacktraceTop:
 __libc_signal_restore_set (set=0xbfcd5e9c) at ../sysdeps/unix/sysv/linux/nptl-signals.h:80
 __GI_raise (sig=6) at ../sysdeps/unix/sysv/linux/raise.c:48
 __GI_abort () at abort.c:79
 __libc_message (action=do_abort, fmt=<optimized out>) at ../sysdeps/posix/libc_fatal.c:181
 malloc_printerr (str=str@entry=0xb6b437e8 "double free or corruption (fasttop)") at malloc.c:5350
Title: gnome-shell assert failure: double free or corruption (fasttop)
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo