Cinnamon Window List intermittently shows wrong icons for LibreOffice Writer and Calc

Start with the standard Window List applet, window-list@cinnamon.org, and reproduce the intermittent Writer/Calc icon swap in an X11 session. Trace how the applet matches WM_CLASS and caches or refreshes application icons; done means repeated opening and closing consistently shows the Writer and Calc icons without restarting Cinnamon.

Distribution

22.3

Package version

6.6.9+zena

Graphics hardware in use

Intel Corporation Arrow Lake-U [Intel Graphics]

Frequency

Quite often

Bug description

A Linux Mint forum discussion appears to describe the same issue on Linux Mint 22.3. Other users report incorrect LibreOffice component icons specifically with Cinnamon's standard Window List. One user also reports that Alt+Tab shows the correct icon and that restarting Cinnamon (Alt+F2 → r) immediately restores the correct icons in the panel.

Forum discussion:
https://forums.linuxmint.com/viewtopic.php?t=462652

The standard Cinnamon Window List applet intermittently displays the wrong application icon for LibreOffice Writer and Calc.

For example:

• A LibreOffice Writer window may show the Calc icon in the panel.
• A LibreOffice Calc window may show the Writer icon.
• Sometimes the icons are displayed correctly randomly.

The problem occurs on a completely fresh installation of Linux Mint 22.3 on a new notebook and on an older notebook aswell.

I am using the standard Window List applet (window-list@cinnamon.org), not the Grouped Window List.

Restarting Cinnamon using Alt+F2, followed by r, immediately corrects the icons of the already open LibreOffice windows.

The problem may reappear later when opening Writer or Calc windows.

Actual result

The Window List sometimes assigns the icon of the wrong LibreOffice component to a window.

For example, Writer is shown with the Calc icon even though the window itself is correctly identified as a Writer window.

Restarting Cinnamon (Alt+F2 → r) immediately changes the incorrect icon to the correct one.

Steps to reproduce

1. Log in to a Cinnamon X11 session.
2. Use the standard Window List applet.
3. Start LibreOffice Writer and LibreOffice Calc.
4. Open and close Writer and Calc windows repeatedly.
5. Observe the application icons in the Cinnamon panel.

The problem is intermittent. Writer may receive the Calc icon or Calc may receive the Writer icon.

Expected behavior

The Window List should consistently use the Writer icon for Writer windows and the Calc icon for Calc windows.

Additional information

Window properties

The LibreOffice windows appear to provide the correct WM_CLASS.

For Writer:

_GTK_APPLICATION_ID(UTF8_STRING) = "org.libreoffice"
WM_CLASS(STRING) = "libreoffice", "libreoffice-writer"
WM_NAME(COMPOUND_TEXT) = "Unbenannt 3 – LibreOffice Writer"
_NET_WM_NAME(UTF8_STRING) = "Unbenannt 3 – LibreOffice Writer"

For Calc:

_GTK_APPLICATION_ID(UTF8_STRING) = "org.libreoffice"
WM_CLASS(STRING) = "libreoffice", "libreoffice-calc"
WM_NAME(COMPOUND_TEXT) = "Unbenannt 2 – LibreOffice Calc"
_NET_WM_NAME(UTF8_STRING) = "Unbenannt 2 – LibreOffice Calc"

Note that _GTK_APPLICATION_ID is org.libreoffice for both applications, while WM_CLASS correctly distinguishes Writer and Calc.

Desktop file configuration

The installed LibreOffice desktop files also appear to contain the correct StartupWMClass and icon definitions.

Writer:

Exec=libreoffice --writer %U
Name=LibreOffice Writer
StartupWMClass=libreoffice-writer
Icon=libreoffice-writer

Calc:

Exec=libreoffice --calc %U
Name=LibreOffice Calc
StartupWMClass=libreoffice-calc
Icon=libreoffice-calc

Therefore the StartupWMClass values correspond correctly to the WM_CLASS values reported by the running windows.

System information

OS: Linux Mint 22.3 Zena
Base: Ubuntu 24.04 Noble
Architecture: x86_64

Desktop: Cinnamon 6.6.9
Window manager: Muffin 6.6.3
GTK: 3.24.41
Display manager: LightDM 1.30.0

Session type: X11
XDG_CURRENT_DESKTOP: X-Cinnamon

Kernel: 7.0.0-30-generic

Cinnamon package:
6.6.9+zena

LibreOffice:
24.2.7.2 420 (Build:2)

libreoffice-core:
4:24.2.7-0ubuntu0.24.04.6

Additional observations

• This is reproducible on a fresh Linux Mint 22.3 installation.
• Reinstalling LibreOffice does not solve the problem.
• The WM_CLASS of Writer and Calc is correct even while the wrong icon is displayed.
• StartupWMClass in the corresponding .desktop files is also correct.
• The problem affects the standard Cinnamon Window List.
• Restarting Cinnamon with Alt+F2 → r immediately fixes the incorrect icons of already open windows without restarting LibreOffice.

This suggests that the problem may be in Cinnamon's Window List/application-to-window icon matching or caching rather than in LibreOffice itself.