Nemo doesn't save settings if runned by root

[vlad0337187]

 * Nemo version: 3.6.4
 * Is issue with desktop or windowed nemo? windowed
 * Distribution - Mint 18.3
 * Graphics hardware *and* driver used Nvidia Geforce GT 630, Nvidia proprietary driver
 * 64 bit

Issue
If to start Nemo from root user, change settings (for example, to double click to open items), that quit and run Nemo again, settings are reset.

Steps to reproduce

• Press right mouse button in any folder and select "run as root"
• in opened window go to behavior settings (edit > preferences > behavior)
• select 'double click to open items' clause
• close Nemo window
• Press right mouse button in any folder and select "run as root"
• ensure that settings are reset

Expected behaviour
After changing settings in Nemo (ran from root) and closing / opening window settings would be saved.

Other information
In IRC they suggested that it's for security reasons.
But such behavior is met only in Linux Mint 18.3, 17.3/18/18.1/18.2 save settings correctly (thanks xenopeek for this info).

I searched in sources for all uses for:
geteuid, nemo_global_preferences_finalize, nemo_global_preferences_init, nemo_application_quit_mainloop, nemo_application_startup,
and did not found such behaviour in logic.
(but I don't know C and don't know how C and GTK applications are arranged)
So I suggest it's a bug.

Workaround (thanks xenopeek for this info):
Settings of nemo are stored in dconf.
There is no /root/.config/dconf directory by default.
Creating that directory and copying the files from my user to root, applies the changes I made by user.
Make the changes you want to do to your own account and then run: sudo cp -R ~/.config/dconf /root/.config

[xenopeek]

I can't reproduce this with Nemo 4.6.4 on Linux Mint 20 Cinnamon: opening a root window and making changes to preferences, such are remembered between sessions and only affect the root window. This looks to have been fixed.

[vlad0337187]

@xenopeek , thank you.
I also can't reproduce it with Nemo 4.6.4 on Fedora 32.

[rlibanez]

After many tests and installations, I have solved installing dbus-x11. In Debian and derivates:

sudo apt install dbus-x11

I noticed that installing Debian Cinnamon or KDE from netinst, the dbus-x11 did not appear as installed and Nemo gave problems. But when installing them from Calamares (live), it automatically installs dbux-x11 and Nemo works without problems.