Found while testing bug 1799042. Running firefox nightly doesn't show neither a pretty name nor the app icon (see attached screenshot).

We actually faced the same problem when we created the Firefox snap package, 6 years ago (bug 1390071 and bug 1436445). As a matter of fact, we've never provided .desktop files in our Linux binaries (bug 296568).

We can reuse the .desktop file we already have in tree[1]. For the record, this file isn't part of the l10n toolchain, like called out in bug 1390152. I don't think it's a big deal for now, but correctly me if I'm wrong, :flod.

On top of the .desktop file, we need to expose app icons too. I'm not sure what the best way is, these days.

[1] https://searchfox.org/mozilla-central/rev/6fc2f6d5335fb6f70f780b5fea5ed77b0719c3b5/taskcluster/docker/firefox-snap/firefox.desktop

This is because Nightly already uses Wayland (MOZ_ENABLE_WAYLAND=1) instead of Xwayland by default.

• Take https://searchfox.org/mozilla-central/source/taskcluster/docker/firefox-snap/firefox.desktop
• change Icon to Icon=MOZ_APP_REMOTINGNAME (and install icons by creating symlinks like Debian or by using xdg-icon-resource like Chrome)
• add StartupWMClass=MOZ_APP_REMOTINGNAME (e.g. StartupWMClass=firefox-nightly)
• name it MOZ_APP_REMOTINGNAME.desktop

Other resources for comparison:
https://salsa.debian.org/mozilla-team/firefox/-/blob/release/master/debian/browser.desktop.in#L103
https://github.com/archlinux/svntogit-packages/blob/packages/firefox/trunk/firefox.desktop

Chrome

• adds a daily cronjob to ensure the chrome repository is readded after disto upgrades
• adds desktop file, menu file, default-apps file, etc.
• installs icons with xdg-icon-resource (in google-chrome-stable_current_amd64.deb/control.tar.xz/postinst)

$ dpkg -L google-chrome-stable
/.
/etc
/etc/cron.daily
/opt
/opt/google
/opt/google/chrome
/opt/google/chrome/MEIPreload
/opt/google/chrome/MEIPreload/manifest.json
/opt/google/chrome/MEIPreload/preloaded_data.pb
/opt/google/chrome/WidevineCdm
/opt/google/chrome/WidevineCdm/LICENSE
/opt/google/chrome/WidevineCdm/_platform_specific
/opt/google/chrome/WidevineCdm/_platform_specific/linux_x64
/opt/google/chrome/WidevineCdm/_platform_specific/linux_x64/libwidevinecdm.so
/opt/google/chrome/WidevineCdm/manifest.json
/opt/google/chrome/chrome
/opt/google/chrome/chrome-management-service
/opt/google/chrome/chrome-sandbox
/opt/google/chrome/chrome_100_percent.pak
/opt/google/chrome/chrome_200_percent.pak
/opt/google/chrome/chrome_crashpad_handler
/opt/google/chrome/cron
/opt/google/chrome/cron/google-chrome
/opt/google/chrome/default-app-block
/opt/google/chrome/default_apps
/opt/google/chrome/default_apps/external_extensions.json
/opt/google/chrome/google-chrome
/opt/google/chrome/icudtl.dat
/opt/google/chrome/libEGL.so
/opt/google/chrome/libGLESv2.so
/opt/google/chrome/liboptimization_guide_internal.so
/opt/google/chrome/libqt5_shim.so
/opt/google/chrome/libvk_swiftshader.so
/opt/google/chrome/libvulkan.so.1
/opt/google/chrome/locales
/opt/google/chrome/locales/af.pak
/opt/google/chrome/locales/am.pak
/opt/google/chrome/locales/ar.pak
/opt/google/chrome/locales/bg.pak
/opt/google/chrome/locales/bn.pak
/opt/google/chrome/locales/ca.pak
/opt/google/chrome/locales/cs.pak
/opt/google/chrome/locales/da.pak
/opt/google/chrome/locales/de.pak
/opt/google/chrome/locales/el.pak
/opt/google/chrome/locales/en-GB.pak
/opt/google/chrome/locales/en-US.pak
/opt/google/chrome/locales/es-419.pak
/opt/google/chrome/locales/es.pak
/opt/google/chrome/locales/et.pak
/opt/google/chrome/locales/fa.pak
/opt/google/chrome/locales/fi.pak
/opt/google/chrome/locales/fil.pak
/opt/google/chrome/locales/fr.pak
/opt/google/chrome/locales/gu.pak
/opt/google/chrome/locales/he.pak
/opt/google/chrome/locales/hi.pak
/opt/google/chrome/locales/hr.pak
/opt/google/chrome/locales/hu.pak
/opt/google/chrome/locales/id.pak
/opt/google/chrome/locales/it.pak
/opt/google/chrome/locales/ja.pak
/opt/google/chrome/locales/kn.pak
/opt/google/chrome/locales/ko.pak
/opt/google/chrome/locales/lt.pak
/opt/google/chrome/locales/lv.pak
/opt/google/chrome/locales/ml.pak
/opt/google/chrome/locales/mr.pak
/opt/google/chrome/locales/ms.pak
/opt/google/chrome/locales/nb.pak
/opt/google/chrome/locales/nl.pak
/opt/google/chrome/locales/pl.pak
/opt/google/chrome/locales/pt-BR.pak
/opt/google/chrome/locales/pt-PT.pak
/opt/google/chrome/locales/ro.pak
/opt/google/chrome/locales/ru.pak
/opt/google/chrome/locales/sk.pak
/opt/google/chrome/locales/sl.pak
/opt/google/chrome/locales/sr.pak
/opt/google/chrome/locales/sv.pak
/opt/google/chrome/locales/sw.pak
/opt/google/chrome/locales/ta.pak
/opt/google/chrome/locales/te.pak
/opt/google/chrome/locales/th.pak
/opt/google/chrome/locales/tr.pak
/opt/google/chrome/locales/uk.pak
/opt/google/chrome/locales/ur.pak
/opt/google/chrome/locales/vi.pak
/opt/google/chrome/locales/zh-CN.pak
/opt/google/chrome/locales/zh-TW.pak
/opt/google/chrome/nacl_helper
/opt/google/chrome/nacl_helper_bootstrap
/opt/google/chrome/nacl_irt_x86_64.nexe
/opt/google/chrome/product_logo_128.png
/opt/google/chrome/product_logo_16.png
/opt/google/chrome/product_logo_24.png
/opt/google/chrome/product_logo_256.png
/opt/google/chrome/product_logo_32.png
/opt/google/chrome/product_logo_32.xpm
/opt/google/chrome/product_logo_48.png
/opt/google/chrome/product_logo_64.png
/opt/google/chrome/resources.pak
/opt/google/chrome/v8_context_snapshot.bin
/opt/google/chrome/vk_swiftshader_icd.json
/opt/google/chrome/xdg-mime
/opt/google/chrome/xdg-settings
/usr
/usr/bin
/usr/share
/usr/share/appdata
/usr/share/appdata/google-chrome.appdata.xml
/usr/share/applications
/usr/share/applications/google-chrome.desktop
/usr/share/doc
/usr/share/doc/google-chrome-stable
/usr/share/doc/google-chrome-stable/changelog.gz
/usr/share/gnome-control-center
/usr/share/gnome-control-center/default-apps
/usr/share/gnome-control-center/default-apps/google-chrome.xml
/usr/share/man
/usr/share/man/man1
/usr/share/man/man1/google-chrome-stable.1.gz
/usr/share/menu
/usr/share/menu/google-chrome.menu
/etc/cron.daily/google-chrome
/usr/bin/google-chrome-stable
/usr/share/man/man1/google-chrome.1.gz

Either snap, flatpak (stable-only, no nightly/beta/esr released IIUC) and debian would share the same template .desktop file which is then customized by script, or different desktop files should be kept manually in sync.

• package name:
  • Debian: use MOZ_APP_REMOTINGNAME (firefox, firefox-beta, firefox-nightly, firefox-esr)
  • Flatpak: keep org.mozilla.firefox (or use org.mozilla.<MOZ_APP_REMOTINGNAME with "-" replaced with "_">. At the moment, only Firefox Stable is released as Flatpak.)
  • Snap: keep firefox (The package is always named firefox and only one channel of it - stable, beta, edge (nightly), esr - can be installed at the same time.)
• desktop file name
  • Debian: use MOZ_APP_REMOTINGNAME.desktop to avoid bug 1826330.
  • Flatpak: keep org.mozilla.firefox.desktop (or use org.mozilla.<MOZ_APP_REMOTINGNAME with "-" replaced with "_">.desktop. At the moment, only Firefox Stable is released as Flatpak.)
  • Snap: rather keep firefox.desktop (The package is always named firefox and only one channel of it - stable, beta, edge (nightly), esr - can be installed at the same time.)
• Name: use/keep MOZ_APP_DISPLAYNAME (Firefox, Firefox Nightly)
• Icon
  • Debian: use Icon=MOZ_APP_REMOTINGNAME
    • add symlinks:
      e.g. /usr/share/MOZ_APP_REMOTINGNAME/browser/chrome/icons/default/default16.png /usr/share/icons/hicolor/16x16/apps/MOZ_APP_REMOTINGNAME.png
  • Flatpak: keep Icon=org.mozilla.firefox (or use org.mozilla.<MOZ_APP_REMOTINGNAME with "-" replaced with "_">. At the moment, only Firefox Stable is released as Flatpak.)
  • Snap: keep
• StartupWMClass
  • Debian: use StartupWMClass=MOZ_APP_REMOTINGNAME
  • Flatpak: keep StartupWMClass=firefox (or use StartupWMClass=MOZ_APP_REMOTINGNAME. At the moment, only Firefox Stable is released as Flatpak.)
  • Snap: add StartupWMClass=MOZ_APP_REMOTINGNAME
    for example, add such a line after this line (repo's nightly branch):
    sed -i 's/StartupWMClass=MOZ_APP_REMOTINGNAME/StartupWMClass=firefox-nightly/' $SNAPCRAFT_PART_INSTALL/firefox.desktop
• Exec
  • Debian:
    • try to use MOZ_APP_REMOTINGNAME, otherwise /usr/lib/MOZ_APP_REMOTINGNAME/firefox.
      Exec=MOZ_APP_REMOTINGNAME %u
Exec=MOZ_APP_REMOTINGNAME --new-window %u
Exec=MOZ_APP_REMOTINGNAME --private-window %u
Exec=MOZ_APP_REMOTINGNAME --ProfileManager %u from flatpak
    • symlink already exists: /usr/lib/MOZ_APP_REMOTINGNAME/firefox /usr/bin/MOZ_APP_REMOTINGNAME
  • Flatpak: keep Exec=firefox (or use Exec=MOZ_APP_REMOTINGNAME %u. At the moment, only Firefox Stable is released as Flatpak.)
  • Snap: keep Exec=firefox %u (The package is always named firefox and only one channel of it - stable, beta, edge (nightly), esr - can be installed at the same time.)
    • add Exec=firefox --ProfileManager %u from flatpak
• MimeType
  • consider using this (snap's + some additions):
    text/html;
    text/xml;
    x-scheme-handler/http;
    x-scheme-handler/https;
    x-scheme-handler/ftp; <-- consider removing (bug 1574475)
    x-scheme-handler/chrome;
    application/xhtml+xml;
    application/xml;
    application/x-xpinstall;
    application/json; <-- from MacOS
    application/pdf; <-- from MacOS
    application/rdf+xml;
    application/rss+xml;
    audio/flac; <-- consider adding
    audio/ogg; <-- from MacOS
    audio/webm; <-- consider adding
    image/avif; <-- from Windows
    image/gif;
    image/jpeg;
    image/png;
    image/svg+xml; <-- from MacOS
    image/webp; <-- from Windows
    video/ogg; <-- from MacOS
    video/webm;

Thank you for your assistance with this bug Darkspirit! Awesome stuff :)

Backed out for causing mochitests failures in browser_all_files_referenced.js.

• Backout link
• Push with failures
• Failure Log
• Failure line: TEST-UNEXPECTED-FAIL | browser/base/content/test/static/browser_all_files_referenced.js | unreferenced file: resource://app/localization/en-US/browser/linuxDesktopEntry.ftl -

https://hg.mozilla.org/mozilla-central/rev/7996177e5a30

Tested on KDE Wayland, Debian Testing:
Thank you very much, the desktop file seems fine, the icon is correctly placed, bug 1826330 is avoided, "Nightly" (first line) "Internet-Browser" (second line) is the menu entry which is perfect.

Change suggestions:

• "x-scheme-handler/ftp" can be removed (bug 1691951). The code has been removed and webextensions can't reimplement it.
• "video/webm" is twice in the list, the first one can be removed.
• Can gif/jpeg/png be moved down above avif or is there a reason for this ordering with two image blocks?

$ sudo dpkg -i target.deb
$ firefox-nightly-try

$ cat /usr/share/applications/firefox-nightly-try.desktop
[Desktop Entry]
Version=1.0
Type=Application
Exec=firefox-nightly-try %u
Terminal=false
X-MultipleArgs=false
Icon=firefox-nightly-try
StartupWMClass=firefox-nightly-try
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;application/json;application/pdf;audio/flac;audio/ogg;audio/webm;image/avif;image/svg+xml;image/webp;video/ogg;video/webm;
StartupNotify=true
Actions=new-window;new-private-window;open-profile-manager;
Name=Nightly
Name[be]=Nightly
Name[cak]=Nightly
Name[cy]=Nightly
Name[de]=Nightly
Name[dsb]=Nightly
Name[en_GB]=Nightly
Name[eo]=Nightly
Name[es_AR]=Nightly
Name[es_CL]=Nightly
Name[fi]=Nightly
Name[fr]=Nightly
Name[fur]=Nightly
Name[gd]=Nightly
Name[gn]=Nightly
Name[he]=Nightly
Name[hsb]=Nightly
Name[hu]=Nightly
Name[ia]=Nightly
Name[it]=Nightly
Name[ja]=Nightly
Name[kab]=Nightly
Name[ko]=Nightly
Name[lo]=Nightly
Name[nb_NO]=Nightly
Name[nn_NO]=Nightly
Name[oc]=Nightly
Name[pa_IN]=Nightly
Name[pl]=Nightly
Name[pt_BR]=Nightly
Name[rm]=Nightly
Name[ru]=Nightly
Name[sk]=Nightly
Name[skr]=Nightly
Name[sr]=Nightly
Name[sv_SE]=Nightly
Name[tg]=Nightly
Name[tr]=Nightly
Name[uk]=Nightly
Name[vi]=Nightly
Name[zh_CN]=Nightly
Name[zh_TW]=Nightly
Comment=Browse the World Wide Web
Comment[be]=Аглядайце Сеціва
Comment[cak]=Tok chupam Word Wide Web
Comment[cy]=Pori'r We Fyd Eang
Comment[de]=Im Internet surfen
Comment[dsb]=Pśeglědajśo World Wide Web
Comment[en_GB]=Browse the World Wide Web
Comment[eo]=Retumi en la reto
Comment[es_AR]=Navegar la World Wide Web
Comment[es_CL]=Navegar por la World Wide Web
Comment[fi]=Selaa Internetiä
Comment[fr]=Naviguer sur le Web
Comment[fur]=Navighe sul Web
Comment[gd]=Rùraich lìon na cruinne
Comment[gn]=Eikundaha World Wide Web rupi
Comment[he]=גלישה באינטרנט
Comment[hsb]=Přehladajće World Wide Web
Comment[hu]=Böngésszen a világhálón
Comment[ia]=Navigar sur le Web
Comment[it]=Naviga sul Web
Comment[ja]=World Wide Web をブラウジングComment[kab]=Browse the World Wide Web
Comment[ko]=월드 와이드 웹 탐색Comment[lo]=ທ່ອງເວັບທົ່ວໂລກ
Comment[nb_NO]=Surf på nettet
Comment[nn_NO]=Surf på nettet
Comment[oc]=Browse the World Wide Web
Comment[pa_IN]=ਵਰਲਡ ਵਾਈਡ ਵੈੱਬ ਬਰਾਊਜ਼ਰ ਕਰੋ
Comment[pl]=Przeglądaj Internet
Comment[pt_BR]=Navegue na World Wide Web
Comment[rm]=Navigar en il web
Comment[ru]=Доступ в Интернет
Comment[sk]=Prehľadávať web (www)
Comment[skr]=ورلڈ وائیڈ ویب براؤز کرو
Comment[sr]=Истражите интернет
Comment[sv_SE]=Surfa på webben
Comment[tg]=Ба шабакаи ҷаҳонии Интернет дастрасӣ пайдо намоед
Comment[tr]=Web’de gezin
Comment[uk]=Переглядайте всесвітню мережу
Comment[vi]=Duyệt web trên toàn thế giới
Comment[zh_CN]=浏览万维网Comment[zh_TW]=瀏覽全球資訊網GenericName=Web Browser
GenericName[be]=Вэб-браўзер
GenericName[cak]=Web Okik'amaya'l
GenericName[cy]=Porwr Gwe
GenericName[de]=Internet-Browser
GenericName[dsb]=Webwobglědowak
GenericName[en_GB]=Web Browser
GenericName[eo]=Retumilo
GenericName[es_AR]=Navegador web
GenericName[es_CL]=Navegador Web
GenericName[fi]=Verkkoselain
GenericName[fr]=Navigateur web
GenericName[fur]=Navigadôr Web
GenericName[gd]=Brabhsair-lìn
GenericName[gn]=Ñanduti Kundahára
GenericName[he]=דפדפן אינטרנט
GenericName[hsb]=Webwobhladowak
GenericName[hu]=Webböngésző
GenericName[ia]=Navigator web
GenericName[it]=Browser web
GenericName[ja]=ウェブブラウザーGenericName[kab]=Iminig web
GenericName[ko]=웹 브라우저GenericName[lo]=ຕົວ​ທ່ອງ​ເວັບ​ເວັບ​ໄຊ​ຕ​໌
GenericName[nb_NO]=Nettleser
GenericName[nn_NO]=Nettlesar
GenericName[oc]=Navegador Web
GenericName[pa_IN]=ਵੈੱਬ ਬਰਾਊਜ਼ਰ
GenericName[pl]=Przeglądarka internetowa
GenericName[pt_BR]=Navegador web
GenericName[rm]=Navigatur web
GenericName[ru]=Веб-браузер
GenericName[sk]=Webový prehliadač
GenericName[skr]=ویب براؤزر
GenericName[sr]=Веб прегледач
GenericName[sv_SE]=Webbläsare
GenericName[tg]=Браузери веб
GenericName[tr]=Web Tarayıcısı
GenericName[uk]=Браузер
GenericName[vi]=Trình duyệt web
GenericName[zh_CN]=Web 浏览器GenericName[zh_TW]=網頁瀏覽器Keywords=Internet;WWW;Browser;Web;Explorer;
Keywords[be]=Internet;WWW;Browser;Web;Explorer;
Keywords[cak]=K'amaya'l;WWW;Okik'amaya'l;Kanob'äl;
Keywords[cy]=Rhyngrwyd;WWW;Porwr;Gwe;Archwiliwr;
Keywords[de]=Internet;WWW;Browser;Web;Explorer;
Keywords[dsb]=Internet;WWW;wobglědowak;Web;Explorer;
Keywords[en_GB]=Internet;WWW;Browser;Web;Explorer;
Keywords[eo]=Interreto;Retumilo;TTT;Teksaĵo;Reto;Internet;WWW;Browser;Web;Explorer;
Keywords[es_AR]=Internet;WWW;Navegador;Web;Explorador;
Keywords[es_CL]=Internet;WWW;Navegador;Web;Explorador;
Keywords[fi]=Internet;WWW;Browser;Web;Explorer;netti;webbi;selain;
Keywords[fr]=Internet;WWW;Browser;Web;Explorer;
Keywords[fur]=Internet;WWW;Browser;Navigadôr;Web;Esploradôr;Explorer;
Keywords[gd]=Internet;WWW;Browser;Web;Explorer;eadar-lìon;brabhsair;brobhsair;lìon;taisgealaiche;
Keywords[gn]=Internet;WWW;Browser;Web;Explorer;
Keywords[he]=אינטרנט;WWW;דפדפן;רשת;סייר;מרשתת;
Keywords[hsb]=Internet;WWW;wobhladowak;Web;Explorer;
Keywords[hu]=Internet;WWW;Böngésző;Web;Világháló;
Keywords[ia]=Internet;WWW;Navigator;Web;Explorator;
Keywords[it]=Internet;WWW;Browser;Web;Explorer;Navigatore;
Keywords[ja]=Internet;WWW;Browser;Web;Explorer;インターネット;ブラウザー;ウェブ;
Keywords[kab]=Internet;WWW;Browser;Web;Explorer;
Keywords[ko]=인터넷;브라우저;웹;탐색기;Internet;WWW;Browser;Web;Explorer;
Keywords[lo]=Internet;WWW;Browser;Web;Explorer;
Keywords[nb_NO]=Internett;WWW;Nettleser;Web;Utforsker;
Keywords[nn_NO]=Internett;WWW;Nettlesar;Web;Utforskar;
Keywords[oc]=Internet;WWW;Navegador;Navigador;Navegator;Navigator;Web;Explorer;
Keywords[pa_IN]=ਇੰਟਰਨੈੱਟ;WWW;ਬਰਾਊਜ਼ਰ;ਵੈੱਬ;ਐਕਸਪਲਰੋਰ;ਵੈਬ;ਇੰਟਰਨੈਟ;
Keywords[pl]=Internet;WWW;Przeglądarka;Browser;Wyszukiwarka;Web;Sieć;Explorer;Eksplorer;Strony;Witryny;internetowe;
Keywords[pt_BR]=Internet;WWW;Browser;Web;Explorer;Navegador;
Keywords[rm]=Internet;WWW;Browser;Web;Explorer;navigatur;
Keywords[ru]=Сеть;Интернет;Браузер;Доступ в Интернет;
Keywords[sk]=Internet;WWW;Prehliadač;Web;Prieskumník;
Keywords[skr]=Internet;WWW;Browser;Web;Explorer;
Keywords[sr]=Internet;WWW;Browser;Web;Explorer;
Keywords[sv_SE]=Internet;WWW;Webbläsare;Webb;Utforskare;
Keywords[tg]=Интернет;WWW;Браузер;Сомона;Ҷустуҷӯгар;
Keywords[tr]=Internet;WWW;Browser;Web;Explorer;İnternet;Tarayıcı
Keywords[uk]=Інтернет;WWW;Браузер;Веб;Переглядач;
Keywords[vi]=Internet;WWW;Trình duyệt;Web;Duyệt web;
Keywords[zh_CN]=Internet;WWW;Browser;Web;Explorer;
Keywords[zh_TW]=網際網路;網路;瀏覽器;網頁;上網;Internet;WWW;Browser;Web;Explorer;
X-GNOME-FullName=Nightly Web Browser
X-GNOME-FullName[be]=Nightly Web Browser
X-GNOME-FullName[cak]=Nightly Web Browser
X-GNOME-FullName[cy]=Nightly Web Browser
X-GNOME-FullName[de]=Nightly Web Browser
X-GNOME-FullName[dsb]=Nightly Web Browser
X-GNOME-FullName[en_GB]=Nightly Web Browser
X-GNOME-FullName[eo]=Nightly Web Browser
X-GNOME-FullName[es_AR]=Nightly Web Browser
X-GNOME-FullName[es_CL]=Nightly Web Browser
X-GNOME-FullName[fi]=Nightly Web Browser
X-GNOME-FullName[fr]=Nightly Web Browser
X-GNOME-FullName[fur]=Nightly Web Browser
X-GNOME-FullName[gd]=Nightly Web Browser
X-GNOME-FullName[gn]=Nightly Web Browser
X-GNOME-FullName[he]=Nightly Web Browser
X-GNOME-FullName[hsb]=Nightly Web Browser
X-GNOME-FullName[hu]=Nightly Web Browser
X-GNOME-FullName[ia]=Nightly Web Browser
X-GNOME-FullName[it]=Nightly Web Browser
X-GNOME-FullName[ja]=Nightly Web Browser
X-GNOME-FullName[kab]=Nightly Web Browser
X-GNOME-FullName[ko]=Nightly Web Browser
X-GNOME-FullName[lo]=Nightly Web Browser
X-GNOME-FullName[nb_NO]=Nightly Web Browser
X-GNOME-FullName[nn_NO]=Nightly Web Browser
X-GNOME-FullName[oc]=Nightly Web Browser
X-GNOME-FullName[pa_IN]=Nightly Web Browser
X-GNOME-FullName[pl]=Nightly Web Browser
X-GNOME-FullName[pt_BR]=Nightly Web Browser
X-GNOME-FullName[rm]=Nightly Web Browser
X-GNOME-FullName[ru]=Nightly Web Browser
X-GNOME-FullName[sk]=Nightly Web Browser
X-GNOME-FullName[skr]=Nightly Web Browser
X-GNOME-FullName[sr]=Nightly Web Browser
X-GNOME-FullName[sv_SE]=Nightly Web Browser
X-GNOME-FullName[tg]=Nightly Web Browser
X-GNOME-FullName[tr]=Nightly Web Browser
X-GNOME-FullName[uk]=Nightly Web Browser
X-GNOME-FullName[vi]=Nightly Web Browser
X-GNOME-FullName[zh_CN]=Nightly Web Browser
X-GNOME-FullName[zh_TW]=Nightly Web Browser

[Desktop Action new-window]
Exec=firefox-nightly-try --new-window %u
Name=New Window
Name[be]=Новае акно
Name[cak]=K'ak'a' Tzuwäch
Name[cy]=Ffenestr Newydd
Name[de]=Neues Fenster
Name[dsb]=Nowe wokno
Name[en_GB]=New Window
Name[eo]=Nova fenestro
Name[es_AR]=Nueva ventana
Name[es_CL]=Nueva ventana
Name[fi]=Uusi ikkuna
Name[fr]=Nouvelle fenêtre
Name[fur]=Gnûf barcon
Name[gd]=Uinneag ùr
Name[gn]=Ovetã pyahu
Name[he]=חלון חדש
Name[hsb]=Nowe wokno
Name[hu]=Új ablak
Name[ia]=Nove fenestra
Name[it]=Nuova finestra
Name[ja]=新しいウィンドウName[kab]=Asfaylu amaynut
Name[ko]=새 창Name[lo]=ວິນໂດໃໝ່
Name[nb_NO]=Nytt vindu
Name[nn_NO]=Nytt vindauge
Name[oc]=Fenèstra novèla
Name[pa_IN]=ਨਵੀਂ ਵਿੰਡੋ
Name[pl]=Nowe okno
Name[pt_BR]=Nova janela
Name[rm]=Nova fanestra
Name[ru]=Новое окно
Name[sk]=Nové okno
Name[skr]=نویں ونڈو
Name[sr]=Нови прозор
Name[sv_SE]=Nytt fönster
Name[tg]=Равзанаи нав
Name[tr]=Yeni pencere
Name[uk]=Нове вікно
Name[vi]=Cửa sổ mới
Name[zh_CN]=新建窗口Name[zh_TW]=開新視窗
[Desktop Action new-private-window]
Exec=firefox-nightly-try --private-window %u
Name=New Private Window
Name[be]=Новае прыватнае акно
Name[cak]=K'ak'a' Ichinan Tzuwäch
Name[cy]=Ffenestr Breifat Newydd
Name[de]=Neues privates Fenster
Name[dsb]=Nowe priwatne wokno
Name[en_GB]=New Private Window
Name[eo]=Nova privata fenestro
Name[es_AR]=Nueva ventana privada
Name[es_CL]=Nueva ventana privada
Name[fi]=Uusi yksityinen ikkuna
Name[fr]=Nouvelle fenêtre privée
Name[fur]=Gnûf barcon privât
Name[gd]=Uinneag phrìobhaideach ùr
Name[gn]=Ovetã ñemi pyahu
Name[he]=חלון פרטי חדש
Name[hsb]=Nowe priwatne wokno
Name[hu]=Új privát ablak
Name[ia]=Nove fenestra private
Name[it]=Nuova finestra anonima
Name[ja]=新しいプライベートウィンドウName[kab]=Asfaylu amaynut n tunigin tusligt
Name[ko]=새 사생활 보호 창Name[lo]=ວິນໂດສ່ວນຕົວໃໝ່
Name[nb_NO]=Nytt privat vindu
Name[nn_NO]=Nytt privat vindauge
Name[oc]=Fenèstra privada novèla
Name[pa_IN]=ਨਵੀਂ ਪ੍ਰਾਈਵੇਟ ਵਿੰਡੋ
Name[pl]=Nowe okno prywatne
Name[pt_BR]=Nova janela privativa
Name[rm]=Nova fanestra privata
Name[ru]=Новое приватное окно
Name[sk]=Nové súkromné okno
Name[skr]=نویں نجی ونڈو
Name[sr]=Нови приватни прозор
Name[sv_SE]=Nytt privat fönster
Name[tg]=Равзанаи хусусии нав
Name[tr]=Yeni gizli pencere
Name[uk]=Приватне вікно
Name[vi]=Cửa sổ riêng tư mới
Name[zh_CN]=新建隐私窗口Name[zh_TW]=開新隱私視窗
[Desktop Action open-profile-manager]
Exec=firefox-nightly-try --ProfileManager
Name=Open Profile Manager
Name[be]=Open Profile Manager
Name[cak]=Open Profile Manager
Name[cy]=Open Profile Manager
Name[de]=Open Profile Manager
Name[dsb]=Open Profile Manager
Name[en_GB]=Open Profile Manager
Name[eo]=Open Profile Manager
Name[es_AR]=Open Profile Manager
Name[es_CL]=Open Profile Manager
Name[fi]=Open Profile Manager
Name[fr]=Open Profile Manager
Name[fur]=Open Profile Manager
Name[gd]=Open Profile Manager
Name[gn]=Open Profile Manager
Name[he]=Open Profile Manager
Name[hsb]=Open Profile Manager
Name[hu]=Open Profile Manager
Name[ia]=Open Profile Manager
Name[it]=Open Profile Manager
Name[ja]=Open Profile Manager
Name[kab]=Open Profile Manager
Name[ko]=Open Profile Manager
Name[lo]=Open Profile Manager
Name[nb_NO]=Open Profile Manager
Name[nn_NO]=Open Profile Manager
Name[oc]=Open Profile Manager
Name[pa_IN]=Open Profile Manager
Name[pl]=Open Profile Manager
Name[pt_BR]=Open Profile Manager
Name[rm]=Open Profile Manager
Name[ru]=Open Profile Manager
Name[sk]=Open Profile Manager
Name[skr]=Open Profile Manager
Name[sr]=Open Profile Manager
Name[sv_SE]=Open Profile Manager
Name[tg]=Open Profile Manager
Name[tr]=Open Profile Manager
Name[uk]=Open Profile Manager
Name[vi]=Open Profile Manager
Name[zh_CN]=Open Profile Manager
Name[zh_TW]=Open Profile Manager

https://hg.mozilla.org/mozilla-central/rev/2183f0c8cb5c

I tweaked the patch to avoid the bustage in Bug 1821988. I will re-land once I see if the tweaks work on this try push https://treeherder.mozilla.org/jobs?repo=try&revision=77df6c7772bbe78d1161a502eb271c517d366538

https://hg.mozilla.org/mozilla-central/rev/f9bda84dbaf7