Gnome-shell crashes if dual monitor connected

THis contains a fresh install of Ubuntu 18.10 to verify the solution at bug 1727356, for Intel-graphic-cards,
which do not support OpenGL 2.1 or higher.
This solution works.
A fresh install does not contain any monitors.xml file, to describe the dual monitor-configuration.
I try to connect an internal laptop-monitor LVDS1 with maximal density 1280 x 800 and an external monitor VGA1
with density 1280 x 1024.
Display-manager gdm3 by default configures the external monitor at the right side of the laptop-monitor.
This results into a logical screen of 2560 x 1024.
THe graphics card only supports a maximal width and height of 2048.

Therefore textures, that are too large, are splitted into multiple slices, that fit.
Unfortunately this is not always done, causing textures of size 2560 x 1024 not being allocated and crashing.

A quick and dirty hardcoded solution limiting the width to 2048 eliminates the crashes:

At cogl/cogl/cogl-texture-2d-sliced.c module setup_spans:
  /* Negative number means no slicing forced by the user */
  if (max_waste <= -1)
    {
      CoglSpan span;
      if (max_width > 2048)
         max_width = 2048;

At cogl/cogl/driver/gl/cogl-texture-2d-gl.c routine allocate_from_bitmap:
  internal_format =
    _cogl_texture_determine_internal_format (tex, cogl_bitmap_get_format (bmp));

  if (width > 2048)
    width = 2048;

In fact the external monitor is physically positioned above the laptop-monitor and this is the configuration we want.
This results into a logical screen of 1280 x 1824 within the limits of the graphics card.

To get this configuration the file monitors.xml was copied to $HOME/.config and to /var/lib/gdm3/.config (to configure login screen).
By default Ubuntu 18.10 uses gdm3 with wayland at the login-screen and gdm3 without wayland after login.

Display-manager gdm3 with wayland ignores this monitors.xml file. To make the file also usable for wayland the <configuration>
must be copied with <connector>VGA-1</connector> i.s.o. <connector>VGA1</connector> and
<connector>LVDS-1</connector> i.s.o. <connector>LVDS1</connector> .

Curious!@#$#.

ProblemType: Bug
DistroRelease: Ubuntu 18.10
Package: evince 3.30.0-2
ProcVersionSignature: Ubuntu 4.18.0-7.8-generic 4.18.5
Uname: Linux 4.18.0-7-generic i686
ApportVersion: 2.20.10-0ubuntu11
Architecture: i386
CurrentDesktop: ubuntu:GNOME
Date: Sat Sep 29 01:41:55 2018
ProcEnviron:
 LANGUAGE=en_US:en
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: evince
UpgradeStatus: No upgrade log present (probably fresh install)