<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> </head> <body> 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 I'm seeing a problem I haven't been able to figure out on the new VM, which has a newer version of the VNC server than the old VM. I run a VNC server (Xtigervnc) on the VM with the ctwm window manger. The Xtigervnc version is: <blockquote> <tt>Xvnc TigerVNC 1.10.0 - built Apr 9 2020 06:49:31</tt><tt> </tt><tt>Copyright (C) 1999-2019 TigerVNC Team and many others (see README.rst)</tt><tt> </tt><tt>See <a class="moz-txt-link-freetext" href="https://www.tigervnc.org">https://www.tigervnc.org</a> for information on TigerVNC.</tt><tt> </tt><tt>Underlying X server release 12008000, The X.Org Foundation</tt> </blockquote> I typically connect to the VNC server through an ssh tunnel using a VNC viewer running on a physical Windows 10 workstation 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: <blockquote> <tt>Button1 = m : title | window | icon : f.function "move-or-raise"</tt><tt> </tt><tt>Button2 = m : title | window | icon : f.menu "OperateWindow"</tt><tt> </tt><tt>Button3 = m : title | window | icon : f.function "move-or-lower" "F1" = : all : f.iconify</tt> </blockquote> On the new VM, this all works fine for a while: F1 iconifies the window, Meta-Left will move or raise the window, etc. However, after about a week of use, it stops working. Restarting ctwm (or running twm instead) does not fix the problem. The only thing that fixes it (temporarily) is restarting the VNC server, which is a pain. I don't know where the problem lies, but I suspect it is in the Xvnc server. The only difference I've been able to find between a working server and a broken server is in the "current input event mask". A diff of xdpyinfo shows the following, where display :8 is working and display :7 is broken: <blockquote> <tt>% diff dpy8.txt dpy7.txt</tt><tt> </tt><tt>1c1</tt><tt> </tt><tt>< name of display: :8</tt><tt> </tt><tt>---</tt><tt> </tt><tt>> name of display: :7</tt><tt> </tt><tt>19c19</tt><tt> </tt><tt>< focus: PointerRoot</tt><tt> </tt><tt>---</tt><tt> </tt><tt>> focus: window 0x180000d, revert to PointerRoot</tt><tt> </tt><tt>60,63c60,63</tt><tt> </tt><tt>< current input event mask: 0xd0001d</tt><tt> </tt><tt>< KeyPressMask ButtonPressMask ButtonReleaseMask </tt><tt> </tt><tt>< EnterWindowMask SubstructureRedirectMask PropertyChangeMask </tt><tt> </tt><tt>< ColormapChangeMask </tt><tt> </tt><tt>---</tt><tt> </tt><tt>> current input event mask: 0xd2001f</tt><tt> </tt><tt>> KeyPressMask KeyReleaseMask ButtonPressMask </tt><tt> </tt><tt>> ButtonReleaseMask EnterWindowMask StructureNotifyMask </tt><tt> </tt><tt>> SubstructureRedirectMask PropertyChangeMask ColormapChangeMask </tt><tt> </tt><tt>% </tt><tt> </tt> </blockquote> So, when the Xvnc server gets into this broken state, KeyReleaseMask and StructureNotifyMask are set in the input event mask. Could the fact that these bits are set in the input event mask explain the problem? Any ideas on what the problem is or how to fix it? Thanks, John D. This e-mail may contain information that is privileged or confidential. If you are not the intended recipient, please delete the e-mail and any attachments and notify us immediately. </body> </html>