[xfce4-terminal] Large delay in prompt echoing after completion of a command which runs inside a tmux session

[Daniel Fishman]

> The xfce 4. machine also has much older xfce4-terminal version, I guess.
> 
> What is the distribution on which you're seeing the problem?
> 

Yes, the xfce 4.8 has xfce4-terminal 0.4.8.
The problem occurs on Archlinux.