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merkata

Member

Registered: 2012-03-20

Posts: 4

[Xvnc] [tigervnc] Added unknown keysym [hex] to keycode [num]

Hi all,

I'm posting here, because I was unable to find anything on the internet about this issue:

I have a (arch) client box connecting via vncviewer to a (arch) server running (tigervnc) vncserver. On my client I use two languages (setxkbmap -layout us,bg (phonetic) -option grp:alt_shift_toggle) - switching and using both languages on the client is fine, both languages work on the server when in a terminal session, however when I connect to the VNC desktop, keys stop responding after a while. Relevant errors in .vnc/hostname:1.log

...
Thu Dec 18 11:32:13 2014
Input:       Added unknown keysym 0x69 to keycode 221
Input:       Added unknown keysym 0x66 to keycode 219

Thu Dec 18 11:35:04 2014
Input:       Added unknown keysym 0x78 to keycode 217

Thu Dec 18 11:35:05 2014
Input:       Added unknown keysym 0x62 to keycode 202

Thu Dec 18 11:35:19 2014
Input:       Added unknown keysym 0x75 to keycode 197
...

Running xev shows some weird stuff - when pressing 'd' for instance

KeyRelease event, serial 38, synthetic NO, window 0x1200001,
    root 0x178, subw 0x1200002, time 175414596, (49,39), root:(50,64),
    state 0x2000, keycode 149 (keysym 0x64, d), same_screen YES,
    XKeysymToKeycode returns keycode: 40
    XLookupString gives 1 bytes: (64) "d"
    XFilterEvent returns: False

and xmodmap -pke would report that 'd' was added to 149

xmodmap -pke | grep 149
keycode 149 = d D d D

The table has room for 255 entries and they fill up really quickly - when it is full, I'm not able to use any 'unknown' keys that werent added to the table before it was full.

Locales on both machines

bg_BG.utf8
C
en_US.utf8
POSIX

tigervnc is at latest version

Does anyone have any suggestions?

Gusar

Member

Registered: 2009-08-25

Posts: 3,605

Re: [Xvnc] [tigervnc] Added unknown keysym [hex] to keycode [num]

I have an idea, but it'll require compiling - ABS and makepkg are your friends, consult the wiki if you don't know how to use them yet.

First, recompile fltk, but replace the tigervnc.patch with this one:

--- fltk-1.3.2.orig/src/Fl_x.cxx        (revision 10433)
+++ fltk-1.3.2/src/Fl_x.cxx        (revision 10434)
@@ -2211,6 +2211,7 @@
   static int result = -1;
 
   if (result == -1) {
+    fl_open_display();
     result = 0;
     unsigned long nitems;
     unsigned long *words = 0;

Once fltk is recompiled with this new patch, recompile tigervnc. Then report if the issue is still happening.

merkata

Member

Registered: 2012-03-20

Posts: 4

Re: [Xvnc] [tigervnc] Added unknown keysym [hex] to keycode [num]

Hi,

Unfortunately the issue persists:

I've recompiled fltk with the patch you provided instead of tigervnc.patch, recompiled tigervnc, installed both new packages - the behavior is the same, unknown keysym errors in the log and an unresponsive keyboard after a while. The only fix currently is to have a .Xmodmap that lacks most multimedia keys and thus you have more entries free in the table, hoping they won't run out.

Also the official response from tigervnc devs on their github:

"This is an unfortunate limitation in the current architecture. So I'm afraid we don't have any easy fix for it. As a workaround you can change the keyboard layout in the VNC session to reset things."