Problem with Xtigervnc: ctwm window manager loses keyboard/mouse bindings

[John DelSignore]

Hi,

I recently moved my "workstation" from CentOS 7.9 to Ubuntu 20.04 (both are actually VMs). I'm seeing a problem I haven't been able to figure out on the new VM, which has a newer version of the TigerVNC server than the old VM.

I run a VNC server (Xtigervnc) on the new VM with the ctwm window manger. The Xtigervnc version is:

    Xvnc TigerVNC 1.10.0 - built Apr  9 2020 06:49:31
    Copyright (C) 1999-2019 TigerVNC Team and many others (see README.rst)
    See https://www.tigervnc.org for information on TigerVNC.
    Underlying X server release 12008000, The X.Org Foundation

I typically connect to the VNC server through an ssh tunnel using a VNC viewer running on a physical Windows 10 desktop or laptop.

I have various ctwm bindings I use to manipulate the windows to raise, lower, move and iconify them. Here are a couple of example bindings:

    Button1 = m    : title | window | icon    : f.function "move-or-raise"
    Button2 = m    : title | window | icon    : f.menu "OperateWindow"
    Button3 = m    : title | window | icon    : f.function "move-or-lower"
    "F1"    =    : all        : f.iconify

On the new VM, this all works fine: F1 iconifies the window, Meta-Left will move or raise the window, etc. However, after about a week of use, those bindings stops working. Restarting ctwm (or running twm instead) does not fix the problem. The only thing that fixes it is restarting the VNC server, which is a pain.

Any ideas on what the problem is or how to fix it?

Thanks, John D.

[John DelSignore]

FYI:

• I tried the TigerVNC 1.12.0 server and the problem also happened with that version.
• I switched to the TurboVNC v2.2.7 server two weeks ago and the problem has not happened since.

So, I think this strongly suggests that the problem is a bug in the TigerVNC server.