Cinnamon -Desktop launcher metabug

Describe the bug Launcher .desktop file keys such as Terminal= and Path= are ignored when clicking a launcher from the desktop. The same .desktop files work fine is set up as a panel or menu launcher.

This isn't a strictly beta issue - it exists in 19.1 and I think it was introduced with Nemo 4.0.6 and this commit which fixed a failure for launchers with pkexec in the Exec=

https://github.com/linuxmint/nemo/commit/816659bb5d1be67ddf3059dddfe91286af3a8eb5

It would be nice to get it fixed in the current beta bug fix run....

To Reproduce Steps to reproduce the behavior:

Please see linked issues.

Expected behavior

Working launchers without workarounds

Frequency Does the issue happen:

[x] Always
[ ] Randomly

Edition (Desktop environment): In which edition is this happening?

[x] Cinnamon Edition
[ ] MATE Edition
[ ] Xfce Edition

Live or post-install: Indicate if this is happening after the installation, or during the live session:

[x] Post-install
[x] Live session

Locale: Paste the output of locale.

steve@steve-HP-Pavilion-g6-Notebook-PC:~$ locale
LANG=en_GB.UTF-8
LANGUAGE=en_GB:en
LC_CTYPE="en_GB.UTF-8"
LC_NUMERIC="en_GB.UTF-8"
LC_TIME="en_GB.UTF-8"
LC_COLLATE="en_GB.UTF-8"
LC_MONETARY="en_GB.UTF-8"
LC_MESSAGES="en_GB.UTF-8"
LC_PAPER="en_GB.UTF-8"
LC_NAME="en_GB.UTF-8"
LC_ADDRESS="en_GB.UTF-8"
LC_TELEPHONE="en_GB.UTF-8"
LC_MEASUREMENT="en_GB.UTF-8"
LC_IDENTIFICATION="en_GB.UTF-8"
LC_ALL

Drivers: Paste the output of inxi -Gxx.

steve@steve-HP-Pavilion-g6-Notebook-PC:~$ inxi -Gxx
Graphics:
  Device-1: Intel 2nd Generation Core Processor Family Integrated Graphics 
  vendor: Hewlett-Packard driver: i915 v: kernel bus ID: 00:02.0 
  chip ID: 8086:0116 
  Display: x11 server: X.Org 1.19.6 driver: modesetting unloaded: fbdev,vesa 
  resolution: 1366x768~60Hz 
  OpenGL: renderer: Mesa DRI Intel Sandybridge Mobile v: 3.3 Mesa 19.0.2 
  compat-v: 3.0 direct render: Yes

Crash report:

''Stack trace'' If you are reporting a crash. Go to "Software Sources" and enable the debug symbols. Then go to "System Reports" and extract the stack trace for your crash and paste it here.

''Dmesg'' If you type dmesg in a terminal, you should see a line corresponding to the crash. Paste it here.

Additional context Add any other context about the problem here.

linuxmint / mint19.2-beta

Cinnamon -Desktop launcher metabug #63