Bug 507892 - Panel shows ESR Firefox as active when launching regular Firefox from taskbar
Summary: Panel shows ESR Firefox as active when launching regular Firefox from taskbar
Status: RESOLVED DOWNSTREAM
Alias: None
Product: plasmashell
Classification: Plasma
Component: Task Manager and Icons-Only Task Manager widgets (other bugs)
Version First Reported In: 6.4.3
Platform: Arch Linux Linux
: NOR minor
Target Milestone: 1.0
Assignee: Plasma Bugs List
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2025-08-05 10:20 UTC by multipliedortegahgkh3
Modified: 2025-08-13 18:17 UTC (History)
3 users (show)

See Also:
Latest Commit:
Version Fixed/Implemented In:
Sentry Crash Report:


Attachments
firefox (32.66 KB, application/x-desktop)
2025-08-10 12:37 UTC, multipliedortegahgkh3
Details
firefox-esr (383 bytes, application/x-desktop)
2025-08-10 12:38 UTC, multipliedortegahgkh3
Details
icon (1.11 KB, image/png)
2025-08-13 02:45 UTC, multipliedortegahgkh3
Details

Note You need to log in before you can comment on or make changes to this bug.
Description multipliedortegahgkh3 2025-08-05 10:20:15 UTC
When both the regular release and ESR (Extended Support Release) version of Firefox are pinned to the Plasma panel, clicking the regular Firefox entry correctly launches the regular Firefox instance. However, the panel incorrectly highlights the Firefox ESR entry as running — even though only the regular version is open. 

Steps to reproduce: 

    Install both regular Firefox and Firefox ESR 
    Pin them to the panel
    Click the regular Firefox entry on the panel to launch it
    Observe that the ESR icon (or ESR task entry) becomes highlighted as "running", not the regular Firefox one
     

Expected behavior:
The panel should highlight the correct Firefox entry

Actual behavior:
The panel incorrectly associates the launched regular Firefox with the ESR task entry. 

Additional info: 

Operating System: Arch Linux 
KDE Plasma Version: 6.4.3
KDE Frameworks Version: 6.16.0
Qt Version: 6.9.1
Kernel Version: 6.15.9-zen1-1-zen (64-bit)
Graphics Platform: Wayland
Processors: 16 × AMD Ryzen 7 6800H with Radeon Graphics
Memory: 16 GiB of RAM (14.8 GiB usable)
Graphics Processor: AMD Radeon Graphics
Comment 1 Nate Graham 2025-08-08 17:41:48 UTC
Can you attach the .desktop files for both apps?
Comment 2 Nate Graham 2025-08-08 17:43:57 UTC
If they were installed from distro repos, the .desktop files will be in /usr/share/applications. If they're Flatpaks, then either /var/lib/flatpak/exports/share/applications/ or ~/.local/share/flatpak/exports/share/applications/, depending on if your Flatpak repo is system-level or user-level. If the apps were installed in another way, you'll have to figure out the location of the .desktop files yourself.
Comment 3 multipliedortegahgkh3 2025-08-10 12:37:46 UTC
Created attachment 183926 [details]
firefox
Comment 4 multipliedortegahgkh3 2025-08-10 12:38:02 UTC
Created attachment 183927 [details]
firefox-esr
Comment 5 multipliedortegahgkh3 2025-08-10 12:39:47 UTC
(In reply to Nate Graham from comment #1)
> Can you attach the .desktop files for both apps?

Okay, I’ve already uploaded the .desktop file.
Comment 6 Nate Graham 2025-08-11 19:21:43 UTC
In firefox-esr.desktop, if you change

StartupWMClass=Firefox

to

StartupWMClass=firefox-esr

and then run `kbuildsycoca6`, and the reboot, does the problem stop happening?
Comment 7 multipliedortegahgkh3 2025-08-13 02:45:05 UTC
Created attachment 184022 [details]
icon
Comment 8 multipliedortegahgkh3 2025-08-13 02:45:13 UTC
(In reply to Nate Graham from comment #6)
> In firefox-esr.desktop, if you change
> 
> StartupWMClass=Firefox
> 
> to
> 
> StartupWMClass=firefox-esr
> 
> and then run `kbuildsycoca6`, and the reboot, does the problem stop
> happening?

This issue is indeed resolved. However, there’s a new problem: when I pin the modified .desktop file to the panel, its icon turns into a blank file, just like in the image I just uploaded. But when I click it to launch Firefox ESR, the icon changes back to the normal Firefox icon. If I place it on the desktop instead, the icon is the normal Firefox icon right away. I haven’t touched the “Icon” line in the .desktop file.
Comment 9 Nate Graham 2025-08-13 18:17:30 UTC
Thanks. That's enough information to point the blame at Firefox here. Basically these are separate apps but aren't properly identifying themselves as such, and they're causing our Task Manager to get confused.

I'd recommend submitting a bug report at https://bugzilla.mozilla.org/, assuming the .desktop files for both apps came from Mozilla.