[Pkg-tigervnc-devel] Bug#1004365: tigervnc-standalone-server: Use of uninitialized value $usedDisplay in concatenation at Wrapper.pm line 297

[joachim.falk at gmx.de]

Package: tigervnc-standalone-server
Version: 1.11.0+dfsg-2
Severity: minor
Tags: patch
X-Debbugs-Cc: joachim.falk at gmx.de

Cosmetic error when creating a VNC server running on a port outside the
range of 5900 - 5999 and then using tigervncserver -list to show all
running instances.

Follow the below steps to reproduce the bug:

...]$ tigervncserver -xstartup /usr/bin/xterm :5877 --

New Xtigervnc server 'flummy.local:11777 (joachim)' on port 11777 for display :5877.
Use xtigervncviewer -SecurityTypes X509Plain -X509CA /home/joachim/.vnc/flummy.local-SrvCert.pem flummy.local:11777 to connect to the VNC server.

...]$ tigervncserver -list
Use of uninitialized value $usedDisplay in concatenation (.) or string at /usr/share/perl5/TigerVNC/Wrapper.pm line 297.
Use of uninitialized value $usedDisplay in concatenation (.) or string at /usr/share/perl5/TigerVNC/Wrapper.pm line 300.
Use of uninitialized value $usedDisplay in concatenation (.) or string at /usr/share/perl5/TigerVNC/Wrapper.pm line 300.

TigerVNC server sessions:

X DISPLAY #	RFB PORT #	PROCESS ID	SERVER
:5877      	11777     	898549    	Xtigervnc

-- System Information:
Debian Release: 11.2
  APT prefers stable-updates
  APT policy: (500, 'stable-updates'), (500, 'stable-security'), (500, 'stable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 5.10.0-11-amd64 (SMP w/16 CPU threads)
Locale: LANG=de_DE.UTF-8, LC_CTYPE=de_DE.UTF-8 (charmap=UTF-8), LANGUAGE not set
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages tigervnc-standalone-server depends on:
ii  libaudit1                   1:3.0-2
ii  libbsd0                     0.11.3-1
ii  libc6                       2.31-13+deb11u2
ii  libfile-readbackwards-perl  1.05-2
ii  libgcrypt20                 1.8.7-6
ii  libgl1                      1.3.2-1
ii  libgnutls30                 3.7.1-5
ii  libjpeg62-turbo             1:2.0.6-4
ii  libpam0g                    1.4.0-9+deb11u1
ii  libpixman-1-0               0.40.0-1
ii  libselinux1                 3.1-3
ii  libstdc++6                  10.2.1-6
ii  libsystemd0                 247.3-6
ii  libunwind8                  1.3.2-2
ii  libxau6                     1:1.0.9-1
ii  libxdmcp6                   1:1.1.2-3
ii  libxfont2                   1:2.0.4-1
ii  perl                        5.32.1-4+deb11u2
hi  tigervnc-common             1.11.0+dfsg-2
ii  x11-xkb-utils               7.7+5
ii  xauth                       1:1.1-1
ii  xkb-data                    2.29-2
ii  zlib1g                      1:1.2.11.dfsg-2

Versions of packages tigervnc-standalone-server recommends:
ii  libgl1-mesa-dri    20.3.5-1
ii  x11-xserver-utils  7.7+8
ii  xfonts-base        1:1.0.5

Versions of packages tigervnc-standalone-server suggests:
ii  xfonts-100dpi    1:1.0.4+nmu1.1
ii  xfonts-75dpi     1:1.0.4+nmu1.1
ii  xfonts-scalable  1:1.0.3-1.2

-- Configuration Files:
/etc/tigervnc/vncserver.users changed [not included]

-- no debconf information
-------------- next part --------------
From e294924ba45618051f3e058a6a2fde1a6a7fc4f1 Mon Sep 17 00:00:00 2001
From: Joachim Falk <joachim.falk at gmx.de>
Date: Sun, 16 Jan 2022 01:55:06 +0100
Subject: [PATCH] Fixed tigervncserver -list for servers not using a rfbport
 from range 5900 - 5999.

Use of uninitialized value $usedDisplay in concatenation (.) or string at /usr/share/perl5/TigerVNC/Wrapper.pm line 353.
Use of uninitialized value $usedDisplay in concatenation (.) or string at /usr/share/perl5/TigerVNC/Wrapper.pm line 356
---
 debian/helpers/usr/share/perl5/TigerVNC/Wrapper.pm | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/debian/helpers/usr/share/perl5/TigerVNC/Wrapper.pm b/debian/helpers/usr/share/perl5/TigerVNC/Wrapper.pm
index 6d9e1f4..f52e754 100644
--- a/debian/helpers/usr/share/perl5/TigerVNC/Wrapper.pm
+++ b/debian/helpers/usr/share/perl5/TigerVNC/Wrapper.pm
@@ -294,12 +294,15 @@ sub runningVncServers {
         $rfbport     = $nr;
         $usedDisplay = $nr - 5900 if $nr >= 5900 && $nr <= 5999;
       }
-      my $name    = "$HOSTFQDN:$usedDisplay";
       my $client  = undef;
       my $server  = "Xtigervnc";
-      my $DISPLAY = -e "/tmp/.X11-unix/X${usedDisplay}"
-        ? ":${usedDisplay}"
-        : "$HOSTFQDN:${usedDisplay}";
+      my ($name, $DISPLAY) = (undef, undef);
+      if (defined $usedDisplay) {
+        $name    = "$HOSTFQDN:$usedDisplay";
+        $DISPLAY = -e "/tmp/.X11-unix/X${usedDisplay}"
+          ? ":${usedDisplay}"
+          : "$HOSTFQDN:${usedDisplay}";
+      }
       {
         my $logFile     = desktopLog($options, $nr);
         my $logFileFh   = File::ReadBackwards->new($logFile);
--
2.34.1