mc term title not restored after subshell or external editor

[carlo.caione]

mc:

GNU Midnight Commander 4.8.22

tmux:

tmux 2.8

configured with:

set -g default-terminal "screen-256color"
set -g set-titles on
setw -g allow-rename on
setw -g automatic-rename off

Running zsh.
Changing 'xterm_title' has no effect.

Steps to reproduce the problem:

1. Run mc
2. Open a subshell with ctrl+o
3. Return to mc by pressing ctrl+o again

What I expect to see:

1. After running mc the tmux title is the string 'mc'
2. After opening a subshell the tmux title is the current directory
3. After returning to mc the tmux title is back to 'mc'

What I see:

1. After running the mc the tmux title is correctly set to 'mc'
2. After opening a subshell the tmux title is correctly the current directory
3. After returning to mc the tmux title is not updated to 'mc' and keep displaying the previous directory name.

Please note this is the simplified way to reproduce a more complicated issue where when returning to mc after having used an external editor that changes the term/tmux title (like vim), the title is not updated by mc which keep displaying the old title (the file name opened in vim in this case).