firefox: "Firefox Web Browser" visible in GNOME, but not in MATE

[David Hedlund]

This issue is easy to reproduce by running live mode in:
* Ubuntu MATE 22.04
* or even easier in Trisquel 11 (a distro based on Ubuntu 22.04 with MATE installed) since the firefox snap package is not installed.

#################################
Firefox snap

Disclaimer: This step is not needed in Trisquel (a distro based on Ubuntu + MATE).

About Firefox snap package that comes with Ubuntu
* In Ubuntu MATE 22.04: The default Panel's Classic Menu: "Internet -> Firefox Web Browser".
* In Ubuntu 22.04: In GNOME, it's visible in the menu. It also added to Favorites.

Selected information about the entry /var/lib/snapd/desktop/applications/firefox_firefox.desktop

Name=Firefox Web Browser
Exec=env BAMF_DESKTOP_FILE_HINT=/var/lib/snapd/desktop/applications/firefox_firefox.desktop /snap/bin/firefox %u
Icon=/snap/firefox/2356/default256.png

¤¤¤¤
Remove firefox snap package

[Disclaimer: snap is not the issue for this bug, because Trisquel (a GNU/Linux distribution based on Ubuntu) ships without snap, and Firefox is not added to the menu when I installed firefox (see the "Install firefox"). We only remove it below to make it possible to install the firefox ppa package.]

Run these steps (from https://www.omgubuntu.co.uk/2022/04/how-to-install-firefox-deb-apt-ubuntu-22-04):

sudo snap remove firefox

echo '
Package: *
Pin: release o=LP-PPA-mozillateam
Pin-Priority: 1001
' | sudo tee /etc/apt/preferences.d/mozilla-firefox

echo 'Unattended-Upgrade::Allowed-Origins:: "LP-PPA-mozillateam:${distro_codename}";' | sudo tee /etc/apt/apt.conf.d/51unattended-upgrades-firefox

For Ubuntu MATE: Right-click on the MATE Panel and click on "Reset all Panels" to remove "Firefox Web Browser".[2]

Status:
* Ubuntu MATE 22.04: "Firefox Web Browser" is removed from the Brisk Menu (actually the whole "Internet" category is removed from the Brisk Menu since "Firefox Web Browser" was the only item).
* Ubuntu 22.04 (GNOME): "Firefox Web Browser" is removed from both the menu and from Favorites.

##############################
Install firefox from the official PPA

Run:
sudo add-apt-repository ppa:mozillateam/ppa
sudo apt update
sudo apt install firefox

Status:
* Ubuntu: "Firefox Web Browser" is added to the menu.
* Ubuntu MATE in the default Panel's Classic Menu: "Internet -> Firefox Web Browser" is NOT added (see attached screenshot). But if you copy the desktop icon, it will become visible right away in the Brisk Menu: cd /usr/share/applications/ && sudo cp firefox.desktop firefoxworking.desktop

* /usr/share/applications/firefox.desktop is added. Selected information about the file:

Name=Firefox Web Browser
Exec=firefox %u
Terminal=false
X-MultipleArgs=false
Type=Application
Icon=firefox
Categories=GNOME;GTK;Network;WebBrowser;
MimeType=text/html;text/xml;application/xhtml+xml;application/xml;application/rss+xml;application/rdf+xml;image/gif;image/jpeg;image/png;x-scheme-handler/http;x-scheme-handler/https;x-scheme-handler/ftp;x-scheme-handler/chrome;video/webm;application/x-xpinstall;
StartupNotify=true
Actions=new-window;new-private-window;

Examine the file:
* desktop-file-validate /usr/share/applications/firefox.desktop # No errors

##############################
Install firefox-esr from the official PPA

This section has been added to examine why the firefox-esr package, but not the firefox package, is adding an entry to the Brisk Menu in Ubuntu MATE.

* Run: sudo apt install firefox-esr

Status:
* Ubuntu 22.04: "Firefox Web Browser"[1] is added to the menu
* Ubuntu MATE 22.04: The default Panel's Classic Menu: "Internet -> Firefox Web Browser"[1] is added. Information about the entry:

* /usr/share/applications/firefox-esr.desktop is added. Selected information about the file:

Name=Firefox Web Browser
Exec=firefox-esr %u
Terminal=false
X-MultipleArgs=false
Type=Application
Icon=firefox-esr
Categories=GNOME;GTK;Network;WebBrowser;
MimeType=text/html;text/xml;application/xhtml+xml;application/xml;application/rss+xml;application/rdf+xml;image/gif;image/jpeg;image/png;x-scheme-handler/http;x-scheme-handler/https;x-scheme-handler/ftp;x-scheme-handler/chrome;video/webm;application/x-xpinstall;
StartupNotify=true
StartupWMClass=firefox-esr-esr102
Actions=new-window;new-private-window;

desktop-file-validate /usr/share/applications/firefox-esr.desktop # No errors

##############################

Install thunderbird from this PPA

This section has been added to examine why the thunderbird package, but not the firefox package, is adding an entry to the Brisk Menu in Ubuntu MATE.

* Run: sudo apt install thunderbird

Status:
* Ubuntu 22.04: "Internet -> Thunderbird Mail" is added to the menu
* Ubuntu MATE 22.04: The default Panel's Classic Menu: "Internet -> Thunderbird Mail" is added.

Information about the entry:
* /usr/share/applications/thunderbird.desktop is added. Selected information about the file:

Name=Thunderbird Mail
Exec=thunderbird %u
Terminal=false
X-MultipleArgs=false
Type=Application
Icon=thunderbird
Categories=Application;Network;Email;
MimeType=x-scheme-handler/mailto;application/x-xpinstall;x-scheme-handler/webcal;x-scheme-handler/mid;message/rfc822;
StartupNotify=true
Actions=Compose;Contacts

desktop-file-validate /usr/share/applications/thunderbird.desktop # No errors

##############################
Temporary solution to add "Firefox Web Browser" to the Brisk Menu in Ubuntu MATE 22.04:

mkdir -p ~/.local/share/applications/
cp /usr/share/applications/firefox.desktop ~/.local/share/applications/

or

cd /usr/share/applications/
sudo cp firefox.desktop firefoxworking.desktop

#############################
References

Issues not related to this bug report:
* 1: A minor issue not related to this bug that I filed at https://bugs.launchpad.net/ubuntu/+source/firefox-esr/+bug/2028439: The entry is correctly added, but "Name=Firefox Web Browser" in /usr/share/applications/firefox-esr.desktop should be changed to "Name=Firefox ESR Web Browser" (Debian stable firefox-esr package ships with "Name=Firefox ESR" in /usr/share/applications/firefox-esr.desktop).
* 2: https://bugs.launchpad.net/ubuntu/+bug/2028577

[David Hedlund (g-public)]

Paul: I have filed many details in this issue, would you like to help me to try to solve it?