User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:80.0) Gecko/20100101 Firefox/80.0

Steps to reproduce:

When I opened Firefox Nightly 80.0a1 (2020-07-13) from terminal on Manjaro Lysia KDE .

Actual results:

It showed the Firefox regular icon. Plus when I clicked start new instance , it opened a new Firefox stable . It is grouped together with Firefox stable . Furthermore, the recent documents are also shown same. The master password prompt also grouped there.
In the image last one is the stable and rest two are nightly windows.

Expected results:

The Nightly and Stable release should be distinguished by the system.

Bugbug thinks this bug should belong to this component, but please revert this change in case of error.

(In reply to Release mgmt bot [:sylvestre / :calixte / :marco for bugbug] from comment #1)

Bugbug thinks this bug should belong to this component, but please revert this change in case of error.

Obviously not.

[Tracking Requested - why for this release]:

(In reply to ibnfulan from comment #0)

Created attachment 9163413 [details]
Nightly, Nightly about and stable.png

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:80.0) Gecko/20100101 Firefox/80.0

Steps to reproduce:

When I opened Firefox Nightly 80.0a1 (2020-07-13) from terminal on Manjaro Lysia KDE .

Actual results:

It showed the Firefox regular icon. Plus when I clicked start new instance , it opened a new Firefox stable . It is grouped together with Firefox stable . Furthermore, the recent documents are also shown same. The master password prompt also grouped there.
In the image last one is the stable and rest two are nightly windows.

Expected results:

The Nightly and Stable release should be distinguished by the system.

Is it possible to provide a higher resolution screenshot? Also a paste of about:support might be helpful.

Getting the WM_CLASS here may be helpful. bug 1151753 comment 9 may be relevant here if the naming changed much then that could be affecting WM_CLASS

If this only happens when Firefox is updated then this is bug 849571. Starting Firefox from the window manger launcher or command line uses the correct icon.

Happens on both Wayland and X11.

Happens when launching from command line.

Happens when launching from 'activities' in Gnome.

chrome://branding/locale/brand.properties is:

brandShorterName=Nightly
brandShortName=Nightly
brandFullName=Firefox Nightly
brandProductName=Firefox
vendorShortName=Mozilla

syncBrandShortName=Sync