[Pkg-lxde-maintainers] Bug#982099: lxpanel: randomly fails to display one of the configured launchers

[Francesco Poli (wintermute)]

Package: lxpanel
Version: 0.10.0-3
Severity: important

Hello!

First of all thanks for maintaining this nice panel in Debian.
I am giving it a try, in order to check whether I can switch to
it from fbpanel, which [risks] being removed from Debian.

[risks]: <https://bugs.debian.org/980122>


Unfortunately, I am experiencing what seems to be a bug.

I configured two launchers in the Application Launch Bar, but it rather
often happens that lxpanel fails to display one of them.
At that point (without changing anything in the configuration), I kill
lxpanel and start it again:

  $ killall -TERM lxpanel
  $ lxpanel &

After doing so, lxpanel may fail again to display one of the two launchers.
Hence, I kill it and restart it again.
After repeating this process a number of times, lxpanel is again able to
display both my launchers. But nothing changed in the configuration, so
the issue seems to be non-deterministic (maybe some race condition?).

See the attached screenshots for the correct panel portion
(with_both_launchers.png) and the incorrectly displayed panel portion
(without_one_launcher.png).


Please investigate/fix the bug and/or forward my bug report upstream.
Thanks for your time and helpfulness!


My lxpanel configuration follows.

  $ cat ~/.local/share/applications/uxterm-start-login.desktop 
  [Desktop Entry]
  Type=Application
  Name=Terminal
  Icon=/usr/share/icons/hicolor/scalable/apps/xterm-color.svg
  Exec=/usr/bin/uxterm -ls
  Terminal=false
  Categories=X-LXPanel;
  $ cat ~/.local/share/applications/xscreensaver-lock-screen.desktop 
  [Desktop Entry]
  Type=Application
  Name=Lock screen
  Icon=/usr/share/pixmaps/xscreensaver.svg
  Exec=/usr/bin/xscreensaver-command -lock
  Terminal=false
  Categories=X-LXPanel;
  $ cat ~/.config/lxpanel/launchtaskbar.cfg 
  [special_cases]
  synaptic=synaptic-pkexec
  soffice.bin=libreoffice
  x-terminal-emulator=lxterminal
  $ cat ~/.config/lxpanel/default/config
  [Command]
  $ cat ~/.config/lxpanel/default/panels/panel 
  # lxpanel <profile> config file. Manually editing is not recommended.
  # Use preference dialog in lxpanel to adjust config when you can.
  
  Global {
    edge=bottom
    allign=left
    margin=275
    widthtype=percent
    width=100
    height=28
    transparent=1
    tintcolor=#dcdad5
    alpha=255
    setdocktype=1
    setpartialstrut=1
    usefontcolor=1
    fontcolor=#10394d
    usefontsize=0
    fontsize=10
    background=0
    backgroundfile=/usr/share/lxpanel/images/background.png
    align=right
    iconsize=24
  }
  Plugin {
    type=launchbar
    Config {
      Button {
        id=uxterm-start-login.desktop
      }
      Button {
        id=xscreensaver-lock-screen.desktop
      }
    }
  }
  Plugin {
    type=space
    Config {
      Size=10
    }
  }
  Plugin {
    type=pager
    Config {
    }
  }
  Plugin {
    type=space
    Config {
      Size=10
    }
    expand=0
  }
  Plugin {
    type=taskbar
    expand=1
    Config {
      tooltips=1
      IconsOnly=0
      AcceptSkipPager=1
      ShowIconified=1
      ShowMapped=1
      ShowAllDesks=0
      UseMouseWheel=1
      UseUrgencyHint=1
      FlatButton=0
      MaxTaskWidth=150
      spacing=1
      GroupedTasks=0
      DisableUpscale=0
      UseSmallerIcons=-1
    }
  }
  Plugin {
    type=space
    Config {
      Size=10
    }
  }
  Plugin {
    type=tray
    Config {
    }
  }
  Plugin {
    type=space
    Config {
      Size=10
    }
  }
  Plugin {
    type=dclock
    Config {
      ClockFmt=%R
      TooltipFmt=%a, %d %b %Y
      BoldFont=1
      IconOnly=0
      CenterText=1
    }
  }
  Plugin {
    type=space
    Config {
      Size=5
    }
  }





-- System Information:
Debian Release: bullseye/sid
  APT prefers testing
  APT policy: (800, 'testing'), (500, 'unstable')
Architecture: amd64 (x86_64)

Kernel: Linux 5.10.0-3-amd64 (SMP w/4 CPU threads)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE=en_US:en
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages lxpanel depends on:
ii  libasound2           1.2.4-1.1
ii  libc6                2.31-9
ii  libcairo2            1.16.0-5
ii  libcurl3-gnutls      7.74.0-1
ii  libfm-gtk4           1.3.1-1.1
ii  libfm-modules        1.3.1-1.1
ii  libfm4               1.3.1-1.1
ii  libgdk-pixbuf-2.0-0  2.42.2+dfsg-1
ii  libglib2.0-0         2.66.4-1
ii  libgtk2.0-0          2.24.33-1
ii  libiw30              30~pre9-13.1
ii  libkeybinder0        0.3.1-2.1
ii  libmenu-cache3       1.1.0-1.1
ii  libpango-1.0-0       1.46.2-3
ii  libwnck22            2.30.7-6
ii  libx11-6             2:1.7.0-2
ii  libxml2              2.9.10+dfsg-6.3+b1
ii  lxmenu-data          0.1.5-2.1
ii  lxpanel-data         0.10.0-3

Versions of packages lxpanel recommends:
ii  libnotify-bin                  0.7.9-2
ii  notification-daemon            3.20.0-4
pn  pavucontrol | gnome-alsamixer  <none>
ii  xkb-data                       2.29-2
ii  xterm [x-terminal-emulator]    363-1

Versions of packages lxpanel suggests:
ii  chromium [www-browser]     88.0.4324.146-1
ii  firefox-esr [www-browser]  68.7.0esr-1
ii  menu                       2.1.48
ii  w3m [www-browser]          0.5.3+git20210102-2

-- no debconf information
-------------- next part --------------
A non-text attachment was scrubbed...
Name: with_both_launchers.png
Type: image/png
Size: 2457 bytes
Desc: not available
URL: <http://alioth-lists.debian.net/pipermail/pkg-lxde-maintainers/attachments/20210206/545435b0/attachment.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: without_one_launcher.png
Type: image/png
Size: 1414 bytes
Desc: not available
URL: <http://alioth-lists.debian.net/pipermail/pkg-lxde-maintainers/attachments/20210206/545435b0/attachment-0001.png>