Desktop icons are shown using the wrong image

[Norbert]

Steps to reproduce:
1. Install Ubuntu 18.04 LTS
2. Login to default GNOME Shell session
3. Copy some application icon to the desktop - for example with

    cp /usr/share/applications/gedit.desktop ~/Desktop/
    chown +x ~/Desktop/gedit.desktop # for sure

4. Minimize all windows to show desktop

Expected behavior:
* copied Gedit desktop icon is shown on desktop with its application icon

Actual behavior:
* copied Gedit desktop icon is shown but uses wrong image

Notes:
* first seen on AskUbuntu - https://askubuntu.com/q/1099860/66509 .
* GNOME FlashBack (from `gnome-panel` package) session is also affected.
* this problem was introduced with 18.04 LTS, the 16.04 LTS do not have problems with desktop-icons.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: nautilus 1:3.26.3-0ubuntu4
ProcVersionSignature: Ubuntu 4.15.0-23.25-generic 4.15.18
Uname: Linux 4.15.0-23-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.2
Architecture: amd64
Date: Tue Dec 11 00:25:26 2018
GsettingsChanges:
 b'org.gnome.nautilus.window-state' b'sidebar-width' b'196'
 b'org.gnome.nautilus.window-state' b'geometry' b"'890x548+268+38'"
 b'org.gnome.nautilus.desktop' b'network-icon-visible' b'true'
InstallationDate: Installed on 2018-04-28 (226 days ago)
InstallationMedia: Ubuntu 18.04 LTS "Bionic Beaver" - Release amd64 (20180426)
SourcePackage: nautilus
UpgradeStatus: No upgrade log present (probably fresh install)
usr_lib_nautilus:

[Daniel van Vugt (vanvugt)]

Assigned to 'nautilus' only. The contents of the desktop window, including icons, are known to the 'nautilus-desktop' process only.

[Sebastien Bacher (seb128)]

The desktop view has been removed from nautilus in 3.30 which deprecates this bug