Menu editor shows systemwide .desktop entries instead of user-configured ones

I installed Steam on my system with the official .deb package.
This created /usr/share/applications/steam.desktop to show a shortcut to Steam in Xubuntu's main menu.
The corresponding entry correctly shows up in the menu editor.

I had to change this entry commandline to preload some .so files. Apparently, modifying a systemwide entry caused the create of some $HOME/.local/share/applications/steam.desktop.

When using the menu (ie. clicking the Steam icon), the modified command line is run, as expected.

However, when editing the menu, the system default entry is show instead, and I could not find an entry corresponding to the $HOME/.local/share/applications/steam.desktop. One thus has to look directly for this file to know ans modify the entry.

I would have expected the menu editor to display the menu in a manner consistent with the behaviour it has when using it (ie. showing the user-wide entry, not the system-wide entry it replaces).

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: menulibre 2.1.2-0ubuntu1
ProcVersionSignature: Ubuntu 4.4.0-10.25-generic 4.4.3
Uname: Linux 4.4.0-10-generic x86_64
ApportVersion: 2.20-0ubuntu3
Architecture: amd64
Date: Tue Mar 8 20:19:07 2016
InstallationDate: Installed on 2016-03-06 (2 days ago)
InstallationMedia: Xubuntu 16.04 LTS "Xenial Xerus" - Alpha amd64 (20160224)
PackageArchitecture: all
ProcEnviron:
 LANGUAGE=fr_FR
 TERM=xterm
 PATH=(custom, no user)
 LANG=fr_FR.UTF-8
 SHELL=/bin/bash
SourcePackage: menulibre
UpgradeStatus: No upgrade log present (probably fresh install)