feat: Correctly start backup before-write session files, b=no-bug, c=folders

fix: Add a flag to change labels when restoring, b=bug #12152 , c=no-component
fix: Remove clip overflow from nav-bar and update rust version, b=no-bug, c=workflows, common
2026-05-27 23:35:09 +00:00 · 2026-02-13 00:01:35 +01:00 · 2026-02-12 20:19:02 +01:00 · 2026-02-12 19:58:58 +01:00 · 2026-02-12 18:41:40 +01:00 · 2026-02-12 17:59:18 +01:00
110 changed files with 1282 additions and 626 deletions
--- a/.github/workflows/linux-release-build.yml
+++ b/.github/workflows/linux-release-build.yml
@@ -92,7 +92,6 @@ jobs:

      - name: Fix Rust version
        run: |
-          # Install a rust version compatible with LLVM 18
          curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y --default-toolchain $(cat .rust-toolchain)
          source $HOME/.cargo/env

--- a/.github/workflows/sync-upstream.yml
+++ b/.github/workflows/sync-upstream.yml
@@ -73,15 +73,13 @@ jobs:
            npm run sync
          fi

-      - name: Run formatter
-        if: steps.check-upstream-branch.outputs.branch_exists == 'false'
-        run: |
-          sudo apt install python3-autopep8
-          npm run pretty
+      - name: Install autopep8
+        run: sudo apt install python3-autopep8

      - name: Check if any files changed
        id: git-check
        run: |
+          npm run pretty
          if [ -n "$(git status --porcelain)" ]; then
            echo "files_changed=true" >> $GITHUB_OUTPUT
          else
@@ -111,6 +109,15 @@ jobs:
        if: steps.git-check.outputs.files_changed == 'true'
        run: python3 scripts/import_external_tests.py || true

+      - name: Import external patches
+        if: steps.git-check.outputs.files_changed == 'true'
+        run: python3 scripts/import_external_patches.py || true
+
+      - name: Run formatter
+        if: steps.check-upstream-branch.outputs.branch_exists == 'false'
+        run: |
+          npm run pretty
+
      - name: Create pull request
        uses: peter-evans/create-pull-request@v7
        if: steps.git-check.outputs.files_changed == 'true'
--- a/.prettierignore
+++ b/.prettierignore
@@ -37,5 +37,6 @@ src/zen/common/ZenEmojis.mjs

 src/zen/split-view/zen-decks.css
 src/zen/workspaces/zen-workspaces.css
+src/zen/common/styles/zen-toolbar.css

 *.inc
--- a/.rust-toolchain
+++ b/.rust-toolchain
@@ -1 +1 @@
-1.83
+1.89
--- a/README.md
+++ b/README.md
@@ -34,8 +34,8 @@ Zen is a firefox-based browser with the aim of pushing your productivity to a ne

 ### Firefox Versions

- [`Release`](https://zen-browser.app/download) - Is currently built using Firefox version `147.0.2`! 🚀
- [`Twilight`](https://zen-browser.app/download?twilight) - Is currently built using Firefox version `RC 147.0.2`!
+- [`Release`](https://zen-browser.app/download) - Is currently built using Firefox version `147.0.3`! 🚀
+- [`Twilight`](https://zen-browser.app/download?twilight) - Is currently built using Firefox version `RC 147.0.3`!

 ### Contributing

--- a/build/firefox-cache/l10n-last-commit-hash
+++ b/build/firefox-cache/l10n-last-commit-hash
@@ -1 +1 @@
-7712a9ac90683965f71be525fe2827467632715d
+b1e00b74d3791a5a7bbd6ba3d32b69b60471e73b
--- a/configs/common/mozconfig
+++ b/configs/common/mozconfig
@@ -9,9 +9,6 @@ ac_add_options --with-app-basename=Zen
 # Localization (Must be an absolute path)
 ac_add_options --with-l10n-base="${topsrcdir}/browser/locales"

-# See https://github.com/zen-browser/desktop/issues/11917 for future plans.
-# We should be removing this at some point and start supporting XDG dirs.
-ac_add_options --with-user-appdir=".${binName}"
 export MOZ_APP_BASENAME=Zen
 export MOZ_BRANDING_DIRECTORY=${brandingDir}
 export MOZ_OFFICIAL_BRANDING_DIRECTORY=${brandingDir}
@@ -85,6 +82,11 @@ if test "$ZEN_RELEASE"; then
  export MOZ_PACKAGE_JSSHELL=1

  ac_add_options --disable-crashreporter
+
+  # Experimental flag, enabled only on nightly for Firefox.
+  # Should bring in some nice performance improvements, 
+  # but may cause stability issues.
+  ac_add_options --enable-replace-malloc
 fi

 ac_add_options --enable-unverified-updates
--- a/locales/ca/browser/browser/preferences/zen-preferences.ftl
+++ b/locales/ca/browser/browser/preferences/zen-preferences.ftl
@@ -314,4 +314,4 @@ zen-devtools-toggle-storage-shortcut = Commuta l'emmagatzematge
 zen-devtools-toggle-dom-shortcut = Commuta el DOM
 zen-devtools-toggle-accessibility-shortcut = Commuta l'accessibilitat
 zen-close-all-unpinned-tabs-shortcut = Tanca totes les pestanyes no fixades
-zen-new-unsynced-window-shortcut = Nova finestra no sincronitzada
+zen-new-unsynced-window-shortcut = Nova finestra en blanc
--- a/locales/ca/browser/browser/zen-menubar.ftl
+++ b/locales/ca/browser/browser/zen-menubar.ftl
@@ -19,4 +19,4 @@ zen-menubar-appearance-light =
 zen-menubar-appearance-dark = 
    .label = Fosca
 zen-menubar-new-unsynced-window = 
-    .label = New Blank Window
+    .label = Nova finestra en blanc
--- a/locales/cy/browser/browser/preferences/zen-preferences.ftl
+++ b/locales/cy/browser/browser/preferences/zen-preferences.ftl
@@ -314,4 +314,4 @@ zen-devtools-toggle-storage-shortcut = Toglo Storio
 zen-devtools-toggle-dom-shortcut = Toglo DOM
 zen-devtools-toggle-accessibility-shortcut = Toglo Hygyrchedd
 zen-close-all-unpinned-tabs-shortcut = Cau Pob Tab Heb ei Binio
-zen-new-unsynced-window-shortcut = Ffenestr Newydd Heb ei Chydweddu
+zen-new-unsynced-window-shortcut = Ffenestr Wag Newydd
--- a/locales/cy/browser/browser/zen-general.ftl
+++ b/locales/cy/browser/browser/zen-general.ftl
@@ -2,8 +2,8 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.

-zen-panel-ui-current-profile-text = proffil cyfredol
-unified-extensions-description = Mae ychwanegiadau'n cael ei defnyddio er mwyn ychwanegu fwy o weithrediadau i { -brand-short-name }.
+zen-panel-ui-current-profile-text = y proffil cyfredol
+unified-extensions-description = Mae estyniadau'n cael ei defnyddio er mwyn ychwanegu fwy o swyddogaeth i { -brand-short-name }.
 tab-context-zen-reset-pinned-tab = 
    .label = Ailosod Tab wedi'i Binio
    .accesskey = A
@@ -109,7 +109,7 @@ zen-sidebar-notification-updated-tooltip =
 zen-sidebar-notification-restart-safe-mode-label = Rhywbeth wedi torri?
 zen-sidebar-notification-restart-safe-mode-tooltip = 
    .title = Ailgychwyn yn y Modd Diogel
-zen-window-sync-migration-dialog-title = Keep Your Windows in Sync
-zen-window-sync-migration-dialog-message = Zen now syncs windows on the same device, so changes in one window are reflected across the others instantly.
-zen-window-sync-migration-dialog-learn-more = Learn More
-zen-window-sync-migration-dialog-accept = Got It
+zen-window-sync-migration-dialog-title = Cadw Eich Ffenestr Wedi'u Cydweddu
+zen-window-sync-migration-dialog-message = Mae Zen bellach yn cydweddu ffenestri ar yr un ddyfais, felly mae newidiadau mewn un ffenestr yn cael eu dangos ar y lleill yn syth.
+zen-window-sync-migration-dialog-learn-more = Dysgu Rhagor
+zen-window-sync-migration-dialog-accept = Iawn
--- a/locales/cy/browser/browser/zen-menubar.ftl
+++ b/locales/cy/browser/browser/zen-menubar.ftl
@@ -19,4 +19,4 @@ zen-menubar-appearance-light =
 zen-menubar-appearance-dark = 
    .label = Tywyll
 zen-menubar-new-unsynced-window = 
-    .label = New Blank Window
+    .label = Ffenestr Wag Newydd
--- a/locales/en-US/browser/browser/preferences/zen-preferences.ftl
+++ b/locales/en-US/browser/browser/preferences/zen-preferences.ftl
@@ -59,6 +59,9 @@ zen-tabs-select-recently-used-on-close =
 zen-tabs-close-on-back-with-no-history =
    .label = Close tab and switch to its owner tab (or most recently used tab) when going back with no history

+zen-settings-workspaces-sync-unpinned-tabs =
+    .label = Sync only pinned tabs in workspaces
+
 zen-tabs-cycle-by-attribute =
  .label = Ctrl+Tab cycles within Essential or Workspace tabs only
 zen-tabs-cycle-ignore-pending-tabs =
--- a/locales/en-US/browser/browser/zen-general.ftl
+++ b/locales/en-US/browser/browser/zen-general.ftl
@@ -6,7 +6,11 @@ zen-panel-ui-current-profile-text = current profile

 unified-extensions-description = Extensions are used to bring more extra functionality into { -brand-short-name }.
 tab-context-zen-reset-pinned-tab =
-    .label = Reset Pinned Tab
+    .label =
+        { $isEssential ->
+            [true] Reset Essential Tab
+           *[false] Reset Pinned Tab
+        }
    .accesskey = R
 tab-context-zen-add-essential =
    .label = Add to Essentials
@@ -16,7 +20,11 @@ tab-context-zen-remove-essential =
    .label = Remove from Essentials
    .accesskey = R
 tab-context-zen-replace-pinned-url-with-current =
-    .label = Replace Pinned URL with Current
+    .label =
+        { $isEssential ->
+            [true] Replace Essential URL with Current
+           *[false] Replace Pinned URL with Current
+        }
    .accesskey = C
 tab-context-zen-edit-title =
    .label = Change Label...
@@ -137,3 +145,7 @@ zen-window-sync-migration-dialog-title = Keep Your Windows in Sync
 zen-window-sync-migration-dialog-message = Zen now syncs windows on the same device, so changes in one window are reflected across the others instantly.
 zen-window-sync-migration-dialog-learn-more = Learn More
 zen-window-sync-migration-dialog-accept = Got It
+
+zen-appmenu-new-blank-window =
+    .label = New blank window
+
--- a/locales/en-US/browser/browser/zen-menubar.ftl
+++ b/locales/en-US/browser/browser/zen-menubar.ftl
@@ -22,5 +22,5 @@ zen-menubar-appearance-light =
 zen-menubar-appearance-dark =
    .label = Dark

-zen-menubar-new-unsynced-window =
-    .label = New blank window
+zen-menubar-new-blank-window =
+    .label = New Blank Window
--- a/locales/fr/browser/browser/zen-menubar.ftl
+++ b/locales/fr/browser/browser/zen-menubar.ftl
@@ -19,4 +19,4 @@ zen-menubar-appearance-light =
 zen-menubar-appearance-dark = 
    .label = Sombre
 zen-menubar-new-unsynced-window = 
-    .label = New Blank Window
+    .label = Nouvelle fenêtre non synchronisée
--- a/locales/ga-IE/browser/browser/zen-menubar.ftl
+++ b/locales/ga-IE/browser/browser/zen-menubar.ftl
@@ -19,4 +19,4 @@ zen-menubar-appearance-light =
 zen-menubar-appearance-dark = 
    .label = Dorcha
 zen-menubar-new-unsynced-window = 
-    .label = New Blank Window
+    .label = Fuinneog Nua Bán
--- a/locales/he/browser/browser/zen-menubar.ftl
+++ b/locales/he/browser/browser/zen-menubar.ftl
@@ -19,4 +19,4 @@ zen-menubar-appearance-light =
 zen-menubar-appearance-dark = 
    .label = כהה
 zen-menubar-new-unsynced-window = 
-    .label = New Blank Window
+    .label = חלון ריק חדש
--- a/locales/hu/browser/browser/zen-menubar.ftl
+++ b/locales/hu/browser/browser/zen-menubar.ftl
@@ -19,4 +19,4 @@ zen-menubar-appearance-light =
 zen-menubar-appearance-dark = 
    .label = Sötét
 zen-menubar-new-unsynced-window = 
-    .label = New Blank Window
+    .label = Új üres lap
--- a/locales/id/browser/browser/preferences/zen-preferences.ftl
+++ b/locales/id/browser/browser/preferences/zen-preferences.ftl
@@ -49,8 +49,8 @@ zen-tabs-close-on-back-with-no-history =
 zen-tabs-cycle-by-attribute = 
    .label = Ctrl+Tab berputar hanya dalam tab Esensial atau Ruang Kerja
 zen-tabs-cycle-ignore-pending-tabs = 
-    .label = Ignore Pending tabs when cycling with Ctrl+Tab
-zen-tabs-cycle-by-attribute-warning = Ctrl+Tab will cycle by recently used order, as it is enabled
+    .label = Lewati tab tak termuat saat beralih dengan Ctrl+Tab
+zen-tabs-cycle-by-attribute-warning = Ctrl+Tab akan beralih berdasarkan urutan terakhir digunakan
 zen-look-and-feel-compact-toolbar-themed = 
    .label = Gunakan latar belakang bertema untuk bilah atas dalam mode ringkas
 zen-workspace-continue-where-left-off = 
@@ -314,4 +314,4 @@ zen-devtools-toggle-storage-shortcut = Ubah Penyimpanan
 zen-devtools-toggle-dom-shortcut = Ubah DOM
 zen-devtools-toggle-accessibility-shortcut = Ubah Aksesibilitas
 zen-close-all-unpinned-tabs-shortcut = Tutup Semua Tab yang Tidak Disematkan
-zen-new-unsynced-window-shortcut = New Unsynced Window
+zen-new-unsynced-window-shortcut = Jendela Kosong Baru
--- a/locales/id/browser/browser/zen-general.ftl
+++ b/locales/id/browser/browser/zen-general.ftl
@@ -60,8 +60,8 @@ zen-site-data-settings = Pengaturan
 zen-generic-manage = Kelola
 zen-generic-more = Selengkapnya
 zen-generic-next = Lanjut
-zen-essentials-promo-label = Add to Essentials
-zen-essentials-promo-sublabel = Keep your favorite tabs just a click away
+zen-essentials-promo-label = Tambahkan ke Essentials
+zen-essentials-promo-sublabel = Akses tab favorit Anda hanya dengan sekali klik
 # These labels will be used for the site data panel settings
 zen-site-data-setting-allow = Diizinkan
 zen-site-data-setting-block = Diblokir
@@ -109,7 +109,7 @@ zen-sidebar-notification-updated-tooltip =
 zen-sidebar-notification-restart-safe-mode-label = Ada yang rusak?
 zen-sidebar-notification-restart-safe-mode-tooltip = 
    .title = Mulai Ulang dalam Mode Aman
-zen-window-sync-migration-dialog-title = Keep Your Windows in Sync
-zen-window-sync-migration-dialog-message = Zen now syncs windows on the same device, so changes in one window are reflected across the others instantly.
-zen-window-sync-migration-dialog-learn-more = Learn More
-zen-window-sync-migration-dialog-accept = Got It
+zen-window-sync-migration-dialog-title = Jaga Jendela Anda Tetap Sinkron
+zen-window-sync-migration-dialog-message = Zen kini menyinkronkan jendela pada perangkat yang sama, sehingga perubahan di satu jendela akan langsung terlihat di jendela lainnya.
+zen-window-sync-migration-dialog-learn-more = Pelajari Lebih Lanjut
+zen-window-sync-migration-dialog-accept = Oke!
--- a/locales/id/browser/browser/zen-menubar.ftl
+++ b/locales/id/browser/browser/zen-menubar.ftl
@@ -4,19 +4,19 @@

 zen-menubar-toggle-pinned-tabs = 
    .label =
-        { $pinnedAreCollapsed ->
-            [true] Expand Pinned Tabs
-           *[false] Collapse Pinned Tabs
+        { $pinnedAreCollapsed -> 
+         [true] Perluas Tab yang Disematkan 
+         *[false] Ciutkan Tab yang Disematkan 
        }
 zen-menubar-appearance = 
-    .label = Appearance
+    .label = Tampilan
 zen-menubar-appearance-description = 
-    .label = Websites will use:
+    .label = Situs web akan menggunakan:
 zen-menubar-appearance-auto = 
-    .label = Automatic
+    .label = Otomatis
 zen-menubar-appearance-light = 
-    .label = Light
+    .label = Terang
 zen-menubar-appearance-dark = 
-    .label = Dark
+    .label = Gelap
 zen-menubar-new-unsynced-window = 
-    .label = New Blank Window
+    .label = Jendela Kosong Baru
--- a/locales/id/browser/browser/zen-workspaces.ftl
+++ b/locales/id/browser/browser/zen-workspaces.ftl
@@ -4,13 +4,13 @@

 zen-panel-ui-workspaces-text = Ruang Kerja Lainnya
 zen-panel-ui-spaces-label = 
-    .label = Spaces
+    .label = Ruang
 zen-panel-ui-workspaces-create = 
    .label = Buat Ruang
 zen-panel-ui-folder-create = 
    .label = Buat Folder
 zen-panel-ui-new-empty-split = 
-    .label = New Split
+    .label = Split Baru
 zen-workspaces-panel-context-delete = 
    .label = Hapus Ruang
    .accesskey = D
@@ -66,6 +66,6 @@ zen-workspaces-close-all-unpinned-tabs-title =
    .label = Bersihkan
    .tooltiptext = Tutup semua tab yang tidak disematkan
 zen-panel-ui-workspaces-change-forward = 
-    .label = Next Space
+    .label = Ruang Selanjutnya
 zen-panel-ui-workspaces-change-back = 
-    .label = Previous Space
+    .label = Ruang Sebelumnya
--- a/locales/is/browser/browser/zen-menubar.ftl
+++ b/locales/is/browser/browser/zen-menubar.ftl
@@ -19,4 +19,4 @@ zen-menubar-appearance-light =
 zen-menubar-appearance-dark = 
    .label = Dökkt
 zen-menubar-new-unsynced-window = 
-    .label = New Blank Window
+    .label = Nýr auður gluggi
--- a/locales/ko/browser/browser/zen-menubar.ftl
+++ b/locales/ko/browser/browser/zen-menubar.ftl
@@ -19,4 +19,4 @@ zen-menubar-appearance-light =
 zen-menubar-appearance-dark = 
    .label = 다크
 zen-menubar-new-unsynced-window = 
-    .label = New Blank Window
+    .label = 새 빈 창
--- a/locales/lt/browser/browser/preferences/zen-preferences.ftl
+++ b/locales/lt/browser/browser/preferences/zen-preferences.ftl
@@ -314,4 +314,4 @@ zen-devtools-toggle-storage-shortcut = Perjungti saugyklą
 zen-devtools-toggle-dom-shortcut = Perjungti DOM
 zen-devtools-toggle-accessibility-shortcut = Perjungti prieinamumą
 zen-close-all-unpinned-tabs-shortcut = Užverti visas neprisegtas korteles
-zen-new-unsynced-window-shortcut = Naujas nesinchronizuotas langas
+zen-new-unsynced-window-shortcut = Naujas tuščias langas
--- a/locales/lt/browser/browser/zen-general.ftl
+++ b/locales/lt/browser/browser/zen-general.ftl
@@ -60,8 +60,8 @@ zen-site-data-settings = Nustatymai
 zen-generic-manage = Tvarkyti
 zen-generic-more = Daugiau
 zen-generic-next = Sekantis
-zen-essentials-promo-label = Add to Essentials
-zen-essentials-promo-sublabel = Keep your favorite tabs just a click away
+zen-essentials-promo-label = Įtraukti į būtiniausius
+zen-essentials-promo-sublabel = Laikykite mėgstamas korteles vos nuo vienu paspaudimu
 # These labels will be used for the site data panel settings
 zen-site-data-setting-allow = Leidžiama
 zen-site-data-setting-block = Užblokuota
@@ -109,7 +109,7 @@ zen-sidebar-notification-updated-tooltip =
 zen-sidebar-notification-restart-safe-mode-label = Kažkas sugedo?
 zen-sidebar-notification-restart-safe-mode-tooltip = 
    .title = Paleisti iš naujo saugioje režime
-zen-window-sync-migration-dialog-title = Keep Your Windows in Sync
-zen-window-sync-migration-dialog-message = Zen now syncs windows on the same device, so changes in one window are reflected across the others instantly.
-zen-window-sync-migration-dialog-learn-more = Learn More
-zen-window-sync-migration-dialog-accept = Got It
+zen-window-sync-migration-dialog-title = Išlaikykite savo langus sinchronizuotus
+zen-window-sync-migration-dialog-message = „Zen“ dabar sinchronizuoja langus tame pačiame įrenginyje, todėl viename lange atlikti pakeitimai iš karto atsispindi ir kituose.
+zen-window-sync-migration-dialog-learn-more = Sužinoti daugiau
+zen-window-sync-migration-dialog-accept = Supratau
--- a/locales/lt/browser/browser/zen-menubar.ftl
+++ b/locales/lt/browser/browser/zen-menubar.ftl
@@ -19,4 +19,4 @@ zen-menubar-appearance-light =
 zen-menubar-appearance-dark = 
    .label = Tamsų
 zen-menubar-new-unsynced-window = 
-    .label = New Blank Window
+    .label = Naujas tuščias langas
--- a/locales/pt-BR/browser/browser/zen-menubar.ftl
+++ b/locales/pt-BR/browser/browser/zen-menubar.ftl
@@ -19,4 +19,4 @@ zen-menubar-appearance-light =
 zen-menubar-appearance-dark = 
    .label = Escuro
 zen-menubar-new-unsynced-window = 
-    .label = New Blank Window
+    .label = Nova janela em branco
--- a/locales/pt-PT/browser/browser/zen-general.ftl
+++ b/locales/pt-PT/browser/browser/zen-general.ftl
@@ -18,9 +18,9 @@ tab-context-zen-replace-pinned-url-with-current =
    .label = Substituir o URL Fixado pelo URL Atual
    .accesskey = C
 tab-context-zen-edit-title = 
-    .label = Change Label...
+    .label = Alterar etiqueta...
 tab-context-zen-edit-icon = 
-    .label = Change Icon...
+    .label = Alterar ícone...
 zen-themes-corrupted = O seu ficheiro de modificações do { -brand-short-name } está corrompido. Elas foram redefinidas como iguais às do tema padrão.
 zen-shortcuts-corrupted = O seu ficheiro de atalhos do { -brand-short-name } está corrompido. Eles foram redefinidos para os atalhos padrão.
 # note: Do not translate the "<br/>" tags in the following string
@@ -109,7 +109,7 @@ zen-sidebar-notification-updated-tooltip =
 zen-sidebar-notification-restart-safe-mode-label = Falhou alguma coisa?
 zen-sidebar-notification-restart-safe-mode-tooltip = 
    .title = Reiniciar em Modo de Segurança
-zen-window-sync-migration-dialog-title = Keep Your Windows in Sync
-zen-window-sync-migration-dialog-message = Zen now syncs windows on the same device, so changes in one window are reflected across the others instantly.
+zen-window-sync-migration-dialog-title = Mantenha As Suas Janelas Sincronizadas
+zen-window-sync-migration-dialog-message = Agora, o Zen sincroniza as janelas no dispositivo, pelo que alterações numa janela são refletidas instantaneamente nas outras.
 zen-window-sync-migration-dialog-learn-more = Learn More
-zen-window-sync-migration-dialog-accept = Got It
+zen-window-sync-migration-dialog-accept = Entendido
--- a/locales/pt-PT/browser/browser/zen-menubar.ftl
+++ b/locales/pt-PT/browser/browser/zen-menubar.ftl
@@ -19,4 +19,4 @@ zen-menubar-appearance-light =
 zen-menubar-appearance-dark = 
    .label = Escuro
 zen-menubar-new-unsynced-window = 
-    .label = New Blank Window
+    .label = Nova janela sem sincronização
--- a/locales/ru/browser/browser/preferences/zen-preferences.ftl
+++ b/locales/ru/browser/browser/preferences/zen-preferences.ftl
@@ -314,4 +314,4 @@ zen-devtools-toggle-storage-shortcut = Переключить хранилище
 zen-devtools-toggle-dom-shortcut = Переключить DOM
 zen-devtools-toggle-accessibility-shortcut = Включить/выключить специальные возможности
 zen-close-all-unpinned-tabs-shortcut = Закрыть все не закреплённые вкладки
-zen-new-unsynced-window-shortcut = Новое несинхронизированное окно
+zen-new-unsynced-window-shortcut = Новое пустое окно
--- a/locales/sv-SE/browser/browser/preferences/zen-preferences.ftl
+++ b/locales/sv-SE/browser/browser/preferences/zen-preferences.ftl
@@ -314,4 +314,4 @@ zen-devtools-toggle-storage-shortcut = Växla lagring
 zen-devtools-toggle-dom-shortcut = Växla DOM
 zen-devtools-toggle-accessibility-shortcut = Växla tillgänglighetsinställningar
 zen-close-all-unpinned-tabs-shortcut = Stäng alla flikar som inte är fästa
-zen-new-unsynced-window-shortcut = Nytt osynkroniserat fönster
+zen-new-unsynced-window-shortcut = Nytt tomt fönster
--- a/locales/sv-SE/browser/browser/zen-menubar.ftl
+++ b/locales/sv-SE/browser/browser/zen-menubar.ftl
@@ -19,4 +19,4 @@ zen-menubar-appearance-light =
 zen-menubar-appearance-dark = 
    .label = Mörkt
 zen-menubar-new-unsynced-window = 
-    .label = New Blank Window
+    .label = Nytt tomt fönster
--- a/locales/tr/browser/browser/preferences/zen-preferences.ftl
+++ b/locales/tr/browser/browser/preferences/zen-preferences.ftl
@@ -314,4 +314,4 @@ zen-devtools-toggle-storage-shortcut = Depolamayı Aç/Kapat
 zen-devtools-toggle-dom-shortcut = DOM'u Aç/Kapat
 zen-devtools-toggle-accessibility-shortcut = Erişilebilirliği Aç/Kapat
 zen-close-all-unpinned-tabs-shortcut = Sabitlenmemiş Tüm Sekmeleri Kapat
-zen-new-unsynced-window-shortcut = Senkronize Edilmemiş Yeni Pencere
+zen-new-unsynced-window-shortcut = Yeni Boş Pencere
--- a/locales/tr/browser/browser/zen-menubar.ftl
+++ b/locales/tr/browser/browser/zen-menubar.ftl
@@ -19,4 +19,4 @@ zen-menubar-appearance-light =
 zen-menubar-appearance-dark = 
    .label = Koyu
 zen-menubar-new-unsynced-window = 
-    .label = New Blank Window
+    .label = Yeni Boş Pencere
--- a/locales/zh-TW/browser/browser/preferences/zen-preferences.ftl
+++ b/locales/zh-TW/browser/browser/preferences/zen-preferences.ftl
@@ -314,4 +314,4 @@ zen-devtools-toggle-storage-shortcut = 開啟儲存空間檢測器
 zen-devtools-toggle-dom-shortcut = 開啟 DOM
 zen-devtools-toggle-accessibility-shortcut = 開啟輔助功能
 zen-close-all-unpinned-tabs-shortcut = 關閉所有未釘選的分頁
-zen-new-unsynced-window-shortcut = 開新未同步視窗
+zen-new-unsynced-window-shortcut = 開新初始視窗
--- a/locales/zh-TW/browser/browser/zen-menubar.ftl
+++ b/locales/zh-TW/browser/browser/zen-menubar.ftl
@@ -19,4 +19,4 @@ zen-menubar-appearance-light =
 zen-menubar-appearance-dark = 
    .label = 暗色
 zen-menubar-new-unsynced-window = 
-    .label = 新的初始視窗
+    .label = 開新初始視窗
--- a/locales/zh-TW/browser/browser/zen-workspaces.ftl
+++ b/locales/zh-TW/browser/browser/zen-workspaces.ftl
@@ -49,7 +49,7 @@ zen-panel-ui-gradient-click-to-add = 點擊新增顏色
 zen-workspace-creation-name = 
    .placeholder = 工作區名稱
 zen-move-tab-to-workspace-button = 
-    .label = 移動至……
+    .label = 移動至…
    .tooltiptext = 將此視窗所有頁面移至單一工作區
 zen-workspaces-panel-context-reorder = 
    .label = 排序工作區
--- a/package-lock.json
+++ b/package-lock.json
@@ -5610,9 +5610,9 @@
      }
    },
    "node_modules/lodash": {
-      "version": "4.17.21",
-      "resolved": "https://registry.npmjs.org/lodash/-/lodash-4.17.21.tgz",
-      "integrity": "sha512-v2kDEe57lecTulaDIuNTPy3Ry4gLGJ6Z1O3vE1krgXZNrsQ+LFTGHVxVjcXPs17LhbZVGedAJv8XZ1tvj5FvSg==",
+      "version": "4.17.23",
+      "resolved": "https://registry.npmjs.org/lodash/-/lodash-4.17.23.tgz",
+      "integrity": "sha512-LgVTMpQtIopCi79SJeDiP0TfWi5CNEc/L/aRdTh3yIvmZXTnheWpKjSZhnvMl8iXbC1tFg9gdHHDMLoV7CnG+w==",
      "dev": true,
      "license": "MIT"
    },
--- a/prefs/zen/view.yaml
+++ b/prefs/zen/view.yaml
@@ -54,3 +54,6 @@

 - name: zen.view.draggable-sidebar
  value: true
+
+- name: zen.view.overflow-webext-toolbar
+  value: "@IS_TWILIGHT@"
--- a/prefs/zen/window-sync.yaml
+++ b/prefs/zen/window-sync.yaml
@@ -13,3 +13,6 @@

 - name: zen.window-sync.open-link-in-new-unsynced-window
  value: true
+
+- name: zen.window-sync.sync-only-pinned-tabs
+  value: false
--- a/prefs/zen/zen-urlbar.yaml
+++ b/prefs/zen/zen-urlbar.yaml
@@ -32,6 +32,9 @@
 - name: zen.urlbar.show-pip-button
  value: false

+- name: zen.urlbar.open-on-startup
+  value: true
+
 # Mark: Zen suggestions controls

 - name: zen.urlbar.suggestions.quick-actions
--- a/scripts/download_phab_patch.py
+++ b/scripts/download_phab_patch.py
@@ -1,41 +0,0 @@
-# This Source Code Form is subject to the terms of the Mozilla Public
-# License, v. 2.0. If a copy of the MPL was not distributed with this
-# file, You can obtain one at http://mozilla.org/MPL/2.0/.
-
-import os
-import sys
-import requests
-
-BASE_URI = "https://phabricator.services.mozilla.com"
-OUTPUT_DIR = os.path.join(os.getcwd(), "src", "firefox-patches")
-
-
-def download_phab_patch(phab_id, output_file):
-  """Download a Phabricator patch by its ID and save it to output_file."""
-  patch_url = f"{BASE_URI}/{phab_id}?download=true"
-  try:
-    print(f"Downloading patch from {patch_url}")
-    response = requests.get(patch_url)
-    response.raise_for_status()  # Raise an error for bad responses
-    with open(output_file, 'wb') as f:
-      f.write(response.content)
-    print(f"Patch saved to {output_file}")
-  except requests.RequestException as e:
-    print(f"Error downloading patch: {e}")
-    sys.exit(1)
-
-
-def main():
-  if len(sys.argv) < 2:
-    print("Usage: python download_phab_patch.py <PHABRICATOR_ID> [output_file]", file=sys.stderr)
-    sys.exit(1)
-
-  phab_id = sys.argv[1]
-  output_file = sys.argv[2] if len(sys.argv) > 2 else f"phab_{phab_id}"
-  output_file = os.path.join(OUTPUT_DIR, output_file + ".patch")
-
-  download_phab_patch(phab_id, output_file)
-
-
-if __name__ == "__main__":
-  main()
--- a/scripts/import_external_tests.py
+++ b/scripts/import_external_tests.py
@@ -18,10 +18,18 @@ FILE_PREFIX = """
 # This file is autogenerated by scripts/import_external_tests.py
 # Do not edit manually.

+"""
+
+BROWSER_MANIFEST_LIST_PREFIX = """
 BROWSER_CHROME_MANIFESTS += [
 """

+XPCSHELL_MANIFESTS_LIST_PREFIX = """
+XPCSHELL_TESTS_MANIFESTS += [
+"""
+
 FILE_SUFFIX = "]"
+VALID_MANIFEST_FILES = ["browser.toml", "xpcshell.toml"]


 def get_tests_manifest():
@@ -38,12 +46,17 @@ def validate_tests_path(path, files, ignore_list):
  for ignore in ignore_list:
    if ignore not in files:
      die_with_error(f"Ignore file '{ignore}' not found in tests folder '{path}'")
-  if "browser.toml" not in files or "browser.js" in ignore_list:
-    die_with_error(f"'browser.toml' not found in tests folder '{path}'")
+  if not any(manifest_file in files for manifest_file in VALID_MANIFEST_FILES):
+    die_with_error(f"None of the valid manifest files {VALID_MANIFEST_FILES} found in tests folder '{path}'")


 def disable_and_replace_manifest(manifest, output_path):
-  toml_file = os.path.join(output_path, "browser.toml")
+  toml_file = None
+  for manifest_file in VALID_MANIFEST_FILES:
+    candidate = os.path.join(output_path, manifest_file)
+    if os.path.exists(candidate):
+      toml_file = candidate
+      break
  disabled_tests = manifest.get("disable", [])
  with open(toml_file, "r") as f:
    data = f.read()
@@ -90,8 +103,17 @@ def write_moz_build_file(manifest):
  print(f"Writing moz.build file to '{moz_build_path}'")
  with open(moz_build_path, "w") as f:
    f.write(FILE_PREFIX)
+    f.write(BROWSER_MANIFEST_LIST_PREFIX)
    for test_suite in manifest.keys():
-      f.write(f'\t"{test_suite}/browser.toml",\n')
+      # add for browser.toml first
+      if not manifest[test_suite].get("xpcshell", False):
+        f.write(f'\t"{test_suite}/browser.toml",\n')
+    f.write(FILE_SUFFIX)
+    f.write(XPCSHELL_MANIFESTS_LIST_PREFIX)
+    for test_suite in manifest.keys():
+      # add for xpcshell.toml
+      if manifest[test_suite].get("xpcshell", False):
+        f.write(f'\t"{test_suite}/xpcshell.toml",\n')
    f.write(FILE_SUFFIX)


--- a/scripts/recalculate-patches.sh
+++ b/scripts/recalculate-patches.sh
@@ -11,6 +11,7 @@ npm run import
 IGNORE_FILES=(
  "shared.nsh"
  "ignorePrefs.json"
+  "moz.configure"
 )

 # Recursively find all .patch files in the current directory and its subdirectories
--- a/scripts/run_tests.py
+++ b/scripts/run_tests.py
@@ -56,7 +56,7 @@ def main():
  os.chdir(engine_dir)

  def run_mach_with_paths(test_paths):
-    command = ['./mach', 'mochitest'] + other_args + test_paths
+    command = ['./mach', 'test'] + other_args + test_paths
    # Replace the current process with the mach command
    os.execvp(command[0], command)

--- a/scripts/update_external_patches.py
+++ b/scripts/update_external_patches.py
@@ -0,0 +1,99 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import os
+import sys
+import json
+import requests
+from json_with_comments import JSONWithCommentsDecoder
+
+BASE_URI = "https://phabricator.services.mozilla.com"
+OUTPUT_DIR = os.path.join(os.getcwd(), "src", "external-patches")
+
+
+def die(message):
+  print(f"Error: {message}")
+  sys.exit(1)
+
+
+def download_phab_patch(phab_id, output_file):
+  """Download a Phabricator patch by its ID and save it to output_file."""
+  patch_url = f"{BASE_URI}/{phab_id}?download=true"
+  try:
+    print(f"Downloading patch from {patch_url}")
+    response = requests.get(patch_url)
+    response.raise_for_status()  # Raise an error for bad responses
+    with open(output_file, 'wb') as f:
+      f.write(response.content)
+    print(f"Patch saved to {output_file}")
+  except requests.RequestException as e:
+    die(f"Failed to download patch {phab_id}: {e}")
+
+
+def download_patch_from_url(url, output_file):
+  """Download a patch from a given URL and save it to output_file."""
+  try:
+    print(f"Downloading patch from {url}")
+    response = requests.get(url)
+    response.raise_for_status()  # Raise an error for bad responses
+    with open(output_file, 'wb') as f:
+      f.write(response.content)
+    print(f"Patch saved to {output_file}")
+  except requests.RequestException as e:
+    die(f"Failed to download patch from {url}: {e}")
+
+
+def main():
+  with open(os.path.join(OUTPUT_DIR, "manifest.json"), 'r') as f:
+    manifest = json.load(f, cls=JSONWithCommentsDecoder)
+
+  expected_files = set()
+  for patch in manifest:
+    if patch.get("type") == "phabricator":
+      phab_id = patch.get("id")
+      name = patch.get("name")
+      if not phab_id or not name:
+        die(f"Patch entry missing 'id' or 'name': {patch}")
+      name = name.replace(" ", "_").lower()
+      output_file = os.path.join(OUTPUT_DIR, "firefox", f"{name}.patch")
+      print(f"Processing Phabricator patch: {phab_id} -> {output_file}")
+      download_phab_patch(phab_id, output_file)
+      expected_files.add(output_file)
+    elif patch.get("type") == "local":
+      print(f"Local patch: {patch.get('path')}")
+      expected_files.add(os.path.join(OUTPUT_DIR, patch.get("path")))
+    elif patch.get("type") == "patch":
+      url = patch.get("url")
+      dest = patch.get("dest")
+      if not url or not dest:
+        die(f"Patch entry missing 'url' or 'dest': {patch}")
+      filename = url.split("/")[-1]
+      output_file = os.path.join(OUTPUT_DIR, dest, filename)
+      download_patch_from_url(url, output_file)
+      replaces = patch.get("replaces", {})
+      for replace in replaces.keys():
+        value = replaces[replace]
+        with open(output_file, 'r') as f:
+          content = f.read()
+        if replace not in content:
+          die(f"Replace string '{replace}' not found in {output_file}")
+        with open(output_file, 'w') as f:
+          f.write(content.replace(replace, value))
+      expected_files.add(output_file)
+    else:
+      die(f"Unknown patch type: {patch.get('type')}")
+
+  # Check for unexpected files in the output directory
+  # and remove them if they are not in the expected_files set.
+  for root, dirs, files in os.walk(OUTPUT_DIR):
+    for file in files:
+      if file.endswith(".patch"):
+        file_path = os.path.join(root, file)
+        if file_path not in expected_files:
+          print(f"Removing unexpected patch file: {file_path}")
+          os.remove(file_path)
+
+
+if __name__ == "__main__":
+  main()
--- a/src/browser/base/content/navigator-toolbox-inc-xhtml.patch
+++ b/src/browser/base/content/navigator-toolbox-inc-xhtml.patch
@@ -1,5 +1,5 @@
 diff --git a/browser/base/content/navigator-toolbox.inc.xhtml b/browser/base/content/navigator-toolbox.inc.xhtml
-index 68c24f730d56f548cf1e286198a04f8363529378..71418c93ce7216d71412f2fa67295322bb73abad 100644
+index 68c24f730d56f548cf1e286198a04f8363529378..eb9aa5e77cf549062d8d3770f8057ceafe67c317 100644
 --- a/browser/base/content/navigator-toolbox.inc.xhtml
 +++ b/browser/base/content/navigator-toolbox.inc.xhtml
@@ -2,7 +2,7 @@
@@ -22,16 +22,17 @@ index 68c24f730d56f548cf1e286198a04f8363529378..71418c93ce7216d71412f2fa67295322
   <toolbar id="TabsToolbar"
            class="browser-toolbar browser-titlebar"
            fullscreentoolbar="true"
-@@ -62,6 +61,8 @@
+@@ -62,6 +61,9 @@
           <html:sidebar-pins-promo id="drag-to-pin-promo-card"></html:sidebar-pins-promo>
           <arrowscrollbox id="pinned-tabs-container" orient="horizontal" clicktoscroll=""></arrowscrollbox>
           <splitter orient="vertical" id="vertical-pinned-tabs-splitter" resizebefore="sibling" resizeafter="none" hidden="true"/>
+<html:div id="zen-overflow-extensions-list" skipintoolbarset="true"></html:div>
 +<html:div id="zen-essentials" skipintoolbarset="true"></html:div>
 +<html:div id="zen-tabs-wrapper">
           <hbox class="tab-drop-indicator" hidden="true"/>
           <arrowscrollbox id="tabbrowser-arrowscrollbox" orient="horizontal" flex="1" clicktoscroll="" scrolledtostart="" scrolledtoend="">
             <tab is="tabbrowser-tab" class="tabbrowser-tab" selected="true" visuallyselected="" fadein=""/>
-@@ -81,6 +82,7 @@
+@@ -81,6 +83,7 @@
                               tooltip="dynamic-shortcut-tooltip"
                               data-l10n-id="tabs-toolbar-new-tab"/>
           <html:span id="tabbrowser-tab-a11y-desc" hidden="true"/>
@@ -39,7 +40,7 @@ index 68c24f730d56f548cf1e286198a04f8363529378..71418c93ce7216d71412f2fa67295322
         </tabs>
 
         <toolbarbutton id="new-tab-button"
-@@ -106,9 +108,10 @@
+@@ -106,9 +109,10 @@
 #include private-browsing-indicator.inc.xhtml
     <toolbarbutton class="content-analysis-indicator toolbarbutton-1 content-analysis-indicator-icon"/>
 
--- a/src/browser/components/BrowserContentHandler-sys-mjs.patch
+++ b/src/browser/components/BrowserContentHandler-sys-mjs.patch
@@ -0,0 +1,41 @@
+diff --git a/browser/components/BrowserContentHandler.sys.mjs b/browser/components/BrowserContentHandler.sys.mjs
+index 57a37b5c0d1982ecfff8d94e05fea89895713a58..062dcb0d1de00982bd777c3dc5d62a88a304bc68 100644
+--- a/browser/components/BrowserContentHandler.sys.mjs
+++ b/browser/components/BrowserContentHandler.sys.mjs
+@@ -601,6 +601,28 @@ nsBrowserContentHandler.prototype = {
+       }
+     }
+ 
+    try {
+      let blankWindowParam = cmdLine.handleFlagWithParam("blank-window", false);
+      if (blankWindowParam !== null) {
+        let { uri, principal } = resolveURIInternal(cmdLine, blankWindowParam);
+        if (shouldLoadURI(uri)) {
+          let win = openBrowserWindow(cmdLine, principal, uri.spec);
+          win._zenStartupSyncFlag = 'unsynced';
+          cmdLine.preventDefault = true;
+        }
+      }
+    } catch (e) {
+      if (e.result != Cr.NS_ERROR_INVALID_ARG) {
+        throw e;
+      }
+      if (cmdLine.handleFlag("blank-window", false)) {
+        let win = openBrowserWindow(cmdLine, null, null);
+        win._zenStartupSyncFlag = 'unsynced';
+        cmdLine.preventDefault = true;
+      }
+    }
+
+
+     var searchParam = cmdLine.handleFlagWithParam("search", false);
+     if (searchParam) {
+       doSearch(searchParam, cmdLine);
+@@ -670,6 +692,7 @@ nsBrowserContentHandler.prototype = {
+       "  --new-window <url> Open <url> in a new window.\n" +
+       "  --new-tab <url>    Open <url> in a new tab.\n" +
+       "  --private-window [<url>] Open <url> in a new private window.\n";
+    info += "  --blank-window [<url>]  Open the new blank window.\n";
+     if (AppConstants.platform == "win") {
+       info += "  --preferences      Open Options dialog.\n";
+     } else {
--- a/src/browser/components/customizableui/CustomizableUI-sys-mjs.patch
+++ b/src/browser/components/customizableui/CustomizableUI-sys-mjs.patch
@@ -1,5 +1,5 @@
 diff --git a/browser/components/customizableui/CustomizableUI.sys.mjs b/browser/components/customizableui/CustomizableUI.sys.mjs
-index 9a98f56d83ee38e0f1aa41467b4ddf215c3d90f7..39e947ce083ce3b293337f5dbb40cd0b46db12e2 100644
+index 9a98f56d83ee38e0f1aa41467b4ddf215c3d90f7..c50781a1e8fd1a71baf497ba64d85292fa1347f4 100644
 --- a/browser/components/customizableui/CustomizableUI.sys.mjs
 +++ b/browser/components/customizableui/CustomizableUI.sys.mjs
@@ -14,6 +14,7 @@ ChromeUtils.defineESModuleGetters(lazy, {
@@ -153,7 +153,17 @@ index 9a98f56d83ee38e0f1aa41467b4ddf215c3d90f7..39e947ce083ce3b293337f5dbb40cd0b
   /**
    * Add a widget to an area.
    * If the area to which you try to add is not known to CustomizableUI,
-@@ -7858,7 +7858,7 @@ class OverflowableToolbar {
+@@ -7798,7 +7798,9 @@ class OverflowableToolbar {
+         );
+ 
+         if (webExtList && CustomizableUI.isWebExtensionWidget(child.id)) {
+          if (webExtList.id !== "zen-overflow-extensions-list") {
+           child.setAttribute("cui-anchorid", webExtButtonID);
+          }
+           webExtList.insertBefore(child, webExtList.firstElementChild);
+         } else {
+           child.setAttribute("cui-anchorid", this.#defaultListButton.id);
+@@ -7858,7 +7860,7 @@ class OverflowableToolbar {
         ) {
           continue;
         }
@@ -162,7 +172,7 @@ index 9a98f56d83ee38e0f1aa41467b4ddf215c3d90f7..39e947ce083ce3b293337f5dbb40cd0b
         if (child != aExceptChild) {
           sum += getInlineSize(child);
         }
-@@ -7882,11 +7882,11 @@ class OverflowableToolbar {
+@@ -7882,11 +7884,11 @@ class OverflowableToolbar {
         parseFloat(style.paddingLeft) -
         parseFloat(style.paddingRight) -
         toolbarChildrenWidth;
@@ -176,7 +186,7 @@ index 9a98f56d83ee38e0f1aa41467b4ddf215c3d90f7..39e947ce083ce3b293337f5dbb40cd0b
     });
 
     lazy.log.debug(
-@@ -7901,7 +7901,14 @@ class OverflowableToolbar {
+@@ -7901,7 +7903,14 @@ class OverflowableToolbar {
       Math.max(targetWidth, targetChildrenWidth)
     );
     totalAvailWidth = Math.ceil(totalAvailWidth);
@@ -192,7 +202,7 @@ index 9a98f56d83ee38e0f1aa41467b4ddf215c3d90f7..39e947ce083ce3b293337f5dbb40cd0b
     return { isOverflowing, targetContentWidth, totalAvailWidth };
   }
 
-@@ -7962,7 +7969,11 @@ class OverflowableToolbar {
+@@ -7962,7 +7971,11 @@ class OverflowableToolbar {
             return;
           }
         }
@@ -205,7 +215,7 @@ index 9a98f56d83ee38e0f1aa41467b4ddf215c3d90f7..39e947ce083ce3b293337f5dbb40cd0b
           lazy.log.debug(
             `Need ${minSize} but width is ${totalAvailWidth} so bailing`
           );
-@@ -7995,7 +8006,7 @@ class OverflowableToolbar {
+@@ -7995,7 +8008,7 @@ class OverflowableToolbar {
         }
       }
       if (!inserted) {
@@ -214,7 +224,27 @@ index 9a98f56d83ee38e0f1aa41467b4ddf215c3d90f7..39e947ce083ce3b293337f5dbb40cd0b
       }
       child.removeAttribute("cui-anchorid");
       child.removeAttribute("overflowedItem");
-@@ -8340,7 +8351,7 @@ class OverflowableToolbar {
+@@ -8121,6 +8134,9 @@ class OverflowableToolbar {
+    *   if no such list exists.
+    */
+   get #webExtList() {
+    if (this.#toolbar.getAttribute("addon-webext-overflowtarget") !== this.#webExtListRef?.id) {
+      this.#webExtListRef = null;
+    }
+     if (!this.#webExtListRef) {
+       let targetID = this.#toolbar.getAttribute("addon-webext-overflowtarget");
+       if (!targetID) {
+@@ -8132,6 +8148,9 @@ class OverflowableToolbar {
+       let win = this.#toolbar.ownerGlobal;
+       let { panel } = win.gUnifiedExtensions;
+       this.#webExtListRef = panel.querySelector(`#${targetID}`);
+      if (!this.#webExtListRef) {
+        this.#webExtListRef = win.document.getElementById(targetID);
+      }
+     }
+     return this.#webExtListRef;
+   }
+@@ -8340,7 +8359,7 @@ class OverflowableToolbar {
         break;
       }
       case "mousedown": {
--- a/src/browser/components/preferences/zen-settings.js
+++ b/src/browser/components/preferences/zen-settings.js
@@ -736,6 +736,7 @@ var gZenWorkspacesSettings = {
    Services.prefs.addObserver("zen.glance.enabled", tabsUnloaderPrefListener); // We can use the same listener for both prefs
    Services.prefs.addObserver("zen.workspaces.separate-essentials", tabsUnloaderPrefListener);
    Services.prefs.addObserver("zen.glance.activation-method", tabsUnloaderPrefListener);
+    Services.prefs.addObserver("zen.window-sync.sync-only-pinned-tabs", tabsUnloaderPrefListener);
    Services.prefs.addObserver(
      "zen.tabs.ctrl-tab.ignore-essential-tabs",
      toggleZenCycleByAttrWarning
@@ -745,6 +746,10 @@ var gZenWorkspacesSettings = {
      Services.prefs.removeObserver("zen.glance.enabled", tabsUnloaderPrefListener);
      Services.prefs.removeObserver("zen.glance.activation-method", tabsUnloaderPrefListener);
      Services.prefs.removeObserver("zen.workspaces.separate-essentials", tabsUnloaderPrefListener);
+      Services.prefs.removeObserver(
+        "zen.window-sync.sync-only-pinned-tabs",
+        tabsUnloaderPrefListener
+      );
      Services.prefs.removeObserver(
        "zen.tabs.ctrl-tab.ignore-essential-tabs",
        toggleZenCycleByAttrWarning
@@ -1198,6 +1203,11 @@ Preferences.addAll([
    type: "bool",
    default: true,
  },
+  {
+    id: "zen.window-sync.sync-only-pinned-tabs",
+    type: "bool",
+    default: false,
+  },
 ]);

 Preferences.addSetting({
--- a/src/browser/components/preferences/zenTabsManagement.inc.xhtml
+++ b/src/browser/components/preferences/zenTabsManagement.inc.xhtml
@@ -20,6 +20,9 @@
      <label><html:h2 data-l10n-id="zen-settings-workspaces-header"/></label>
      <description class="description-deemphasized" data-l10n-id="zen-settings-workspaces-description" />

+      <checkbox id="zenWorkspacesSyncUnpinnedTabs"
+            data-l10n-id="zen-settings-workspaces-sync-unpinned-tabs"
+            preference="zen.window-sync.sync-only-pinned-tabs"/>
      <checkbox id="zenWorkspacesHideDefaultContainer"
            data-l10n-id="zen-settings-workspaces-hide-default-container-indicator"
            preference="zen.workspaces.hide-default-container-indicator"/>
--- a/src/browser/components/sessionstore/SessionStartup-sys-mjs.patch
+++ b/src/browser/components/sessionstore/SessionStartup-sys-mjs.patch
@@ -1,5 +1,5 @@
 diff --git a/browser/components/sessionstore/SessionStartup.sys.mjs b/browser/components/sessionstore/SessionStartup.sys.mjs
-index 86600ffb5178599ab23270a964064ca657a3283f..e7014e5bce547d37ec92377a95bad5be4d52152e 100644
+index 86600ffb5178599ab23270a964064ca657a3283f..70d7b5c7d69d3700475d663b595052264c67d351 100644
 --- a/browser/components/sessionstore/SessionStartup.sys.mjs
 +++ b/browser/components/sessionstore/SessionStartup.sys.mjs
@@ -40,6 +40,7 @@ ChromeUtils.defineESModuleGetters(lazy, {
@@ -28,7 +28,16 @@ index 86600ffb5178599ab23270a964064ca657a3283f..e7014e5bce547d37ec92377a95bad5be
     if (this._initialState == null) {
       // No valid session found.
       this._sessionType = this.NO_SESSION;
-@@ -336,12 +339,7 @@ export var SessionStartup = {
+@@ -276,6 +279,8 @@ export var SessionStartup = {
+         `Previous shutdown ok? ${this._previousSessionCrashed}, reason: ${previousSessionCrashedReason}`
+       );
+ 
+      lazy.ZenSessionStore.onCrashCheckpoints(this._initialState);
+
+       Services.obs.addObserver(this, "sessionstore-windows-restored", true);
+ 
+       if (this.sessionType == this.NO_SESSION) {
+@@ -336,12 +341,7 @@ export var SessionStartup = {
   isAutomaticRestoreEnabled() {
     if (this._resumeSessionEnabled === null) {
       this._resumeSessionEnabled =
@@ -42,3 +51,13 @@ index 86600ffb5178599ab23270a964064ca657a3283f..e7014e5bce547d37ec92377a95bad5be
     }
 
     return this._resumeSessionEnabled;
+@@ -354,8 +354,7 @@ export var SessionStartup = {
+    */
+   willRestore() {
+     return (
+-      this.sessionType == this.RECOVER_SESSION ||
+-      this.sessionType == this.RESUME_SESSION
+      true
+     );
+   },
+ 
--- a/src/browser/components/sessionstore/SessionStore-sys-mjs.patch
+++ b/src/browser/components/sessionstore/SessionStore-sys-mjs.patch
@@ -1,5 +1,5 @@
 diff --git a/browser/components/sessionstore/SessionStore.sys.mjs b/browser/components/sessionstore/SessionStore.sys.mjs
-index 2a055f0c5f34f0a2667f659185120c07d38f4e41..2f63071f78782dbc30bde25b3bcaa96faedf6f0b 100644
+index 2a055f0c5f34f0a2667f659185120c07d38f4e41..53465df6060e6765e1e4564d340bba5fbefff5ce 100644
 --- a/browser/components/sessionstore/SessionStore.sys.mjs
 +++ b/browser/components/sessionstore/SessionStore.sys.mjs
@@ -127,6 +127,9 @@ const TAB_EVENTS = [
@@ -63,6 +63,15 @@ index 2a055f0c5f34f0a2667f659185120c07d38f4e41..2f63071f78782dbc30bde25b3bcaa96f
 
     // perform additional initialization when the first window is loading
     if (lazy.RunState.isStopped) {
+@@ -2088,7 +2097,7 @@ var SessionStoreInternal = {
+         // to disk to NOW() to enforce a full interval before the next write.
+         lazy.SessionSaver.updateLastSaveTime();
+ 
+-        if (isPrivateWindow || isTaskbarTab) {
+        if (isPrivateWindow || isTaskbarTab || aWindow.document.documentElement.hasAttribute("zen-unsynced-window")) {
+           this._log.debug(
+             "initializeWindow, the window is private or a web app. Saving SessionStartup.state for possibly restoring later"
+           );
@@ -2131,6 +2140,7 @@ var SessionStoreInternal = {
           null,
           "sessionstore-one-or-no-tab-restored"
@@ -79,7 +88,15 @@ index 2a055f0c5f34f0a2667f659185120c07d38f4e41..2f63071f78782dbc30bde25b3bcaa96f
           !lazy.SessionStartup.willRestore()
         ) {
           // We want to split the window up into pinned tabs and unpinned tabs.
-@@ -2239,6 +2248,15 @@ var SessionStoreInternal = {
+@@ -2211,6 +2220,7 @@ var SessionStoreInternal = {
+         }
+ 
+         if (newWindowState) {
+          lazy.ZenSessionStore.onRestoringClosedWindow(newWindowState);
+           // Ensure that the window state isn't hidden
+           this._restoreCount = 1;
+           let state = { windows: [newWindowState] };
+@@ -2239,6 +2249,15 @@ var SessionStoreInternal = {
       });
       this._shouldRestoreLastSession = false;
     }
@@ -95,7 +112,7 @@ index 2a055f0c5f34f0a2667f659185120c07d38f4e41..2f63071f78782dbc30bde25b3bcaa96f
 
     if (this._restoreLastWindow && aWindow.toolbar.visible) {
       // always reset (if not a popup window)
-@@ -2383,7 +2401,7 @@ var SessionStoreInternal = {
+@@ -2383,7 +2402,7 @@ var SessionStoreInternal = {
 
     var tabbrowser = aWindow.gBrowser;
 
@@ -104,7 +121,7 @@ index 2a055f0c5f34f0a2667f659185120c07d38f4e41..2f63071f78782dbc30bde25b3bcaa96f
 
     TAB_EVENTS.forEach(function (aEvent) {
       tabbrowser.tabContainer.removeEventListener(aEvent, this, true);
-@@ -2434,7 +2452,7 @@ var SessionStoreInternal = {
+@@ -2434,7 +2453,7 @@ var SessionStoreInternal = {
 
       let isLastRegularWindow =
         Object.values(this._windows).filter(
@@ -113,7 +130,7 @@ index 2a055f0c5f34f0a2667f659185120c07d38f4e41..2f63071f78782dbc30bde25b3bcaa96f
         ).length == 1;
       this._log.debug(
         `onClose, closing window isLastRegularWindow? ${isLastRegularWindow}`
-@@ -2491,8 +2509,8 @@ var SessionStoreInternal = {
+@@ -2491,8 +2510,8 @@ var SessionStoreInternal = {
       // 2) Flush the window.
       // 3) When the flush is complete, revisit our decision to store the window
       //    in _closedWindows, and add/remove as necessary.
@@ -124,7 +141,7 @@ index 2a055f0c5f34f0a2667f659185120c07d38f4e41..2f63071f78782dbc30bde25b3bcaa96f
       }
 
       completionPromise = lazy.TabStateFlusher.flushWindow(aWindow).then(() => {
-@@ -2512,8 +2530,9 @@ var SessionStoreInternal = {
+@@ -2512,8 +2531,9 @@ var SessionStoreInternal = {
 
         // Save non-private windows if they have at
         // least one saveable tab or are the last window.
@@ -136,7 +153,7 @@ index 2a055f0c5f34f0a2667f659185120c07d38f4e41..2f63071f78782dbc30bde25b3bcaa96f
 
           if (!isLastWindow && winData.closedId > -1) {
             this._addClosedAction(
-@@ -2589,7 +2608,7 @@ var SessionStoreInternal = {
+@@ -2589,7 +2609,7 @@ var SessionStoreInternal = {
    *        to call this method again asynchronously (for example, after
    *        a window flush).
    */
@@ -145,7 +162,7 @@ index 2a055f0c5f34f0a2667f659185120c07d38f4e41..2f63071f78782dbc30bde25b3bcaa96f
     // Make sure SessionStore is still running, and make sure that we
     // haven't chosen to forget this window.
     if (
-@@ -2606,6 +2625,7 @@ var SessionStoreInternal = {
+@@ -2606,6 +2626,7 @@ var SessionStoreInternal = {
       // _closedWindows from a previous call to this function.
       let winIndex = this._closedWindows.indexOf(winData);
       let alreadyStored = winIndex != -1;
@@ -153,7 +170,7 @@ index 2a055f0c5f34f0a2667f659185120c07d38f4e41..2f63071f78782dbc30bde25b3bcaa96f
       // If sidebar command is truthy, i.e. sidebar is open, store sidebar settings
       let shouldStore = hasSaveableTabs || isLastWindow;
 
-@@ -3408,7 +3428,7 @@ var SessionStoreInternal = {
+@@ -3408,7 +3429,7 @@ var SessionStoreInternal = {
     if (!isPrivateWindow && tabState.isPrivate) {
       return;
     }
@@ -162,7 +179,7 @@ index 2a055f0c5f34f0a2667f659185120c07d38f4e41..2f63071f78782dbc30bde25b3bcaa96f
       return;
     }
 
-@@ -4129,6 +4149,12 @@ var SessionStoreInternal = {
+@@ -4129,6 +4150,12 @@ var SessionStoreInternal = {
         Math.min(tabState.index, tabState.entries.length)
       );
       tabState.pinned = false;
@@ -175,7 +192,7 @@ index 2a055f0c5f34f0a2667f659185120c07d38f4e41..2f63071f78782dbc30bde25b3bcaa96f
 
       if (inBackground === false) {
         aWindow.gBrowser.selectedTab = newTab;
-@@ -4565,6 +4591,8 @@ var SessionStoreInternal = {
+@@ -4565,6 +4592,8 @@ var SessionStoreInternal = {
       // Append the tab if we're opening into a different window,
       tabIndex: aSource == aTargetWindow ? pos : Infinity,
       pinned: state.pinned,
@@ -184,7 +201,19 @@ index 2a055f0c5f34f0a2667f659185120c07d38f4e41..2f63071f78782dbc30bde25b3bcaa96f
       userContextId: state.userContextId,
       skipLoad: true,
       preferredRemoteType,
-@@ -5414,7 +5442,7 @@ var SessionStoreInternal = {
+@@ -5055,9 +5084,10 @@ var SessionStoreInternal = {
+       if (activePageData.title && activePageData.title != activePageData.url) {
+         win.gBrowser.setInitialTabTitle(tab, activePageData.title, {
+           isContentTitle: true,
+          _zenChangeLabelFlag: true,
+         });
+       } else {
+-        win.gBrowser.setInitialTabTitle(tab, activePageData.url);
+        win.gBrowser.setInitialTabTitle(tab, activePageData.url, { _zenChangeLabelFlag: true });
+       }
+     }
+ 
+@@ -5414,7 +5444,7 @@ var SessionStoreInternal = {
 
     for (let i = tabbrowser.pinnedTabCount; i < tabbrowser.tabs.length; i++) {
       let tab = tabbrowser.tabs[i];
@@ -193,7 +222,7 @@ index 2a055f0c5f34f0a2667f659185120c07d38f4e41..2f63071f78782dbc30bde25b3bcaa96f
         removableTabs.push(tab);
       }
     }
-@@ -5525,7 +5553,7 @@ var SessionStoreInternal = {
+@@ -5525,7 +5555,7 @@ var SessionStoreInternal = {
 
     // collect the data for all windows
     for (ix in this._windows) {
@@ -202,7 +231,7 @@ index 2a055f0c5f34f0a2667f659185120c07d38f4e41..2f63071f78782dbc30bde25b3bcaa96f
         // window data is still in _statesToRestore
         continue;
       }
-@@ -5668,11 +5696,12 @@ var SessionStoreInternal = {
+@@ -5668,11 +5698,12 @@ var SessionStoreInternal = {
     }
 
     let tabbrowser = aWindow.gBrowser;
@@ -216,7 +245,7 @@ index 2a055f0c5f34f0a2667f659185120c07d38f4e41..2f63071f78782dbc30bde25b3bcaa96f
     // update the internal state data for this window
     for (let tab of tabs) {
       if (tab == aWindow.FirefoxViewHandler.tab) {
-@@ -5683,6 +5712,9 @@ var SessionStoreInternal = {
+@@ -5683,6 +5714,9 @@ var SessionStoreInternal = {
       tabsData.push(tabData);
     }
 
@@ -226,7 +255,7 @@ index 2a055f0c5f34f0a2667f659185120c07d38f4e41..2f63071f78782dbc30bde25b3bcaa96f
     // update tab group state for this window
     winData.groups = [];
     for (let tabGroup of aWindow.gBrowser.tabGroups) {
-@@ -5695,7 +5727,7 @@ var SessionStoreInternal = {
+@@ -5695,7 +5729,7 @@ var SessionStoreInternal = {
     // a window is closed, point to the first item in the tab strip instead (it will never be the Firefox View tab,
     // since it's only inserted into the tab strip after it's selected).
     if (aWindow.FirefoxViewHandler.tab?.selected) {
@@ -235,7 +264,7 @@ index 2a055f0c5f34f0a2667f659185120c07d38f4e41..2f63071f78782dbc30bde25b3bcaa96f
       winData.title = tabbrowser.tabs[0].label;
     }
     winData.selected = selectedIndex;
-@@ -5810,8 +5842,8 @@ var SessionStoreInternal = {
+@@ -5810,8 +5844,8 @@ var SessionStoreInternal = {
     // selectTab represents.
     let selectTab = 0;
     if (overwriteTabs) {
@@ -246,7 +275,7 @@ index 2a055f0c5f34f0a2667f659185120c07d38f4e41..2f63071f78782dbc30bde25b3bcaa96f
       selectTab = Math.min(selectTab, winData.tabs.length);
     }
 
-@@ -5833,6 +5865,7 @@ var SessionStoreInternal = {
+@@ -5833,6 +5867,7 @@ var SessionStoreInternal = {
     if (overwriteTabs) {
       for (let i = tabbrowser.browsers.length - 1; i >= 0; i--) {
         if (!tabbrowser.tabs[i].selected) {
@@ -254,7 +283,7 @@ index 2a055f0c5f34f0a2667f659185120c07d38f4e41..2f63071f78782dbc30bde25b3bcaa96f
           tabbrowser.removeTab(tabbrowser.tabs[i]);
         }
       }
-@@ -5866,6 +5899,12 @@ var SessionStoreInternal = {
+@@ -5866,6 +5901,12 @@ var SessionStoreInternal = {
         savedTabGroup => !openTabGroupIdsInWindow.has(savedTabGroup.id)
       );
     }
@@ -267,7 +296,7 @@ index 2a055f0c5f34f0a2667f659185120c07d38f4e41..2f63071f78782dbc30bde25b3bcaa96f
 
     // Move the originally open tabs to the end.
     if (initialTabs) {
-@@ -6419,6 +6458,25 @@ var SessionStoreInternal = {
+@@ -6419,6 +6460,25 @@ var SessionStoreInternal = {
 
     // Most of tabData has been restored, now continue with restoring
     // attributes that may trigger external events.
@@ -293,7 +322,7 @@ index 2a055f0c5f34f0a2667f659185120c07d38f4e41..2f63071f78782dbc30bde25b3bcaa96f
 
     if (tabData.pinned) {
       tabbrowser.pinTab(tab);
-@@ -6567,6 +6625,9 @@ var SessionStoreInternal = {
+@@ -6567,6 +6627,9 @@ var SessionStoreInternal = {
         aWindow.gURLBar.readOnly = false;
       }
     }
@@ -303,7 +332,7 @@ index 2a055f0c5f34f0a2667f659185120c07d38f4e41..2f63071f78782dbc30bde25b3bcaa96f
 
     let promiseParts = Promise.withResolvers();
     aWindow.setTimeout(() => {
-@@ -7343,7 +7404,7 @@ var SessionStoreInternal = {
+@@ -7343,7 +7406,7 @@ var SessionStoreInternal = {
 
       let groupsToSave = new Map();
       for (let tIndex = 0; tIndex < window.tabs.length; ) {
@@ -312,7 +341,7 @@ index 2a055f0c5f34f0a2667f659185120c07d38f4e41..2f63071f78782dbc30bde25b3bcaa96f
           // Adjust window.selected
           if (tIndex + 1 < window.selected) {
             window.selected -= 1;
-@@ -7358,7 +7419,7 @@ var SessionStoreInternal = {
+@@ -7358,7 +7421,7 @@ var SessionStoreInternal = {
           );
           // We don't want to increment tIndex here.
           continue;
--- a/src/browser/components/tabbrowser/content/tab-js.patch
+++ b/src/browser/components/tabbrowser/content/tab-js.patch
@@ -1,5 +1,5 @@
 diff --git a/browser/components/tabbrowser/content/tab.js b/browser/components/tabbrowser/content/tab.js
-index 6528da245d922e2ccdb59cbf8106055bc34d1e74..1cd3395961a80e3b48582794b5b5365c9b8386b3 100644
+index 6528da245d922e2ccdb59cbf8106055bc34d1e74..b5d5ac633c06d7d9c909ec9456a5f3c165a6b925 100644
 --- a/browser/components/tabbrowser/content/tab.js
 +++ b/browser/components/tabbrowser/content/tab.js
@@ -21,6 +21,7 @@
@@ -52,7 +52,7 @@ index 6528da245d922e2ccdb59cbf8106055bc34d1e74..1cd3395961a80e3b48582794b5b5365c
         return;
       }
 
-@@ -224,11 +227,21 @@
+@@ -224,11 +227,23 @@
     }
 
     get visible() {
@@ -64,7 +64,6 @@ index 6528da245d922e2ccdb59cbf8106055bc34d1e74..1cd3395961a80e3b48582794b5b5365c
 +      if (!this.isOpen || this.hidden || this.hasAttribute("zen-empty-tab")) {
 +        return false;
 +      }
-+
 +      // Selected tabs are always visible
 +      if (this.selected || this.multiselected || this.hasAttribute("folder-active")) return true;
 +      // Recursively check all parent groups
@@ -75,11 +74,14 @@ index 6528da245d922e2ccdb59cbf8106055bc34d1e74..1cd3395961a80e3b48582794b5b5365c
 +        }
 +        currentParent = currentParent.group;
 +      }
+      if (this.pinned && !this.hasAttribute("zen-essential") && gZenWorkspaces.activeWorkspaceElement?.hasCollapsedPinnedTabs) {
+        return false;
+      }
 +      return true;
     }
 
     get hidden() {
-@@ -307,7 +320,7 @@
+@@ -307,7 +322,7 @@
         return false;
       }
 
@@ -88,7 +90,7 @@ index 6528da245d922e2ccdb59cbf8106055bc34d1e74..1cd3395961a80e3b48582794b5b5365c
     }
 
     get lastAccessed() {
-@@ -384,7 +397,18 @@
+@@ -384,7 +399,18 @@
     }
 
     get group() {
@@ -108,7 +110,7 @@ index 6528da245d922e2ccdb59cbf8106055bc34d1e74..1cd3395961a80e3b48582794b5b5365c
     }
 
     get splitview() {
-@@ -489,6 +513,8 @@
+@@ -489,6 +515,8 @@
         this.style.MozUserFocus = "ignore";
       } else if (
         event.target.classList.contains("tab-close-button") ||
@@ -117,7 +119,7 @@ index 6528da245d922e2ccdb59cbf8106055bc34d1e74..1cd3395961a80e3b48582794b5b5365c
         event.target.classList.contains("tab-icon-overlay") ||
         event.target.classList.contains("tab-audio-button")
       ) {
-@@ -543,6 +569,10 @@
+@@ -543,6 +571,10 @@
       this.style.MozUserFocus = "";
     }
 
@@ -128,7 +130,7 @@ index 6528da245d922e2ccdb59cbf8106055bc34d1e74..1cd3395961a80e3b48582794b5b5365c
     on_click(event) {
       if (event.button != 0) {
         return;
-@@ -603,6 +633,14 @@
+@@ -603,6 +635,14 @@
         // (see tabbrowser-tabs 'click' handler).
         gBrowser.tabContainer._blockDblClick = true;
       }
@@ -143,7 +145,7 @@ index 6528da245d922e2ccdb59cbf8106055bc34d1e74..1cd3395961a80e3b48582794b5b5365c
     }
 
     on_dblclick(event) {
-@@ -626,6 +664,8 @@
+@@ -626,6 +666,8 @@
           animate: true,
           triggeringEvent: event,
         });
--- a/src/browser/components/tabbrowser/content/tabbrowser-js.patch
+++ b/src/browser/components/tabbrowser/content/tabbrowser-js.patch
@@ -1,5 +1,5 @@
 diff --git a/browser/components/tabbrowser/content/tabbrowser.js b/browser/components/tabbrowser/content/tabbrowser.js
-index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..d21c461c4e05fa5b28bc0806b07f9256ca3c9175 100644
+index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..db1c57c8eb4b3d614b5e5aa820871d66b00ec9a4 100644
 --- a/browser/components/tabbrowser/content/tabbrowser.js
 +++ b/browser/components/tabbrowser/content/tabbrowser.js
@@ -398,6 +398,7 @@
@@ -186,11 +186,13 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..d21c461c4e05fa5b28bc0806b07f9256
       // If focus is on the old tab, move it to the new tab.
       if (activeEl == oldTab) {
         newTab.focus();
-@@ -1959,6 +2039,11 @@
+@@ -1958,7 +2038,12 @@
+       return this._setTabLabel(aTab, aLabel);
     }
 
-     _setTabLabel(aTab, aLabel, { beforeTabOpen, isContentTitle, isURL } = {}) {
-+      if (!aTab._zenContentsVisible && !aTab._zenChangeLabelFlag && !aTab._labelIsInitialTitle && !gZenWorkspaces.privateWindowOrDisabled) {
+-    _setTabLabel(aTab, aLabel, { beforeTabOpen, isContentTitle, isURL } = {}) {
+    _setTabLabel(aTab, aLabel, { beforeTabOpen, isContentTitle, isURL, _zenChangeLabelFlag } = {}) {
+      if (!aTab._zenContentsVisible && !aTab._zenChangeLabelFlag && !aTab._labelIsInitialTitle && !gZenWorkspaces.privateWindowOrDisabled && !_zenChangeLabelFlag) {
 +        return false;
 +      }
 +      aLabel = (typeof aTab.zenStaticLabel === "string" && aTab.zenStaticLabel) ? aTab.zenStaticLabel : aLabel;
@@ -777,7 +779,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..d21c461c4e05fa5b28bc0806b07f9256
         options,
         aTab
       );
-+      win._zenStartupSyncFlag = zenForceSync ? 'synced' : 'unsynced';
+      win._zenStartupSyncFlag = (zenForceSync || !Services.prefs.getBoolPref("zen.tabs.dnd-open-blank-window", true)) ? 'synced' : 'unsynced';
 +      return win;
     }
 
--- a/src/browser/components/urlbar/UrlbarMuxerStandard-sys-mjs.patch
+++ b/src/browser/components/urlbar/UrlbarMuxerStandard-sys-mjs.patch
@@ -1,8 +1,17 @@
 diff --git a/browser/components/urlbar/UrlbarMuxerStandard.sys.mjs b/browser/components/urlbar/UrlbarMuxerStandard.sys.mjs
-index c12d875172650dddfe7de623a776149517c83302..66e923ed2c84e350dd7ba7a20e362666cec8f307 100644
+index c12d875172650dddfe7de623a776149517c83302..de24df54f510c44acda8c64584bf483a2cb5650a 100644
 --- a/browser/components/urlbar/UrlbarMuxerStandard.sys.mjs
 +++ b/browser/components/urlbar/UrlbarMuxerStandard.sys.mjs
-@@ -854,6 +854,7 @@ class MuxerUnifiedComplete extends UrlbarMuxer {
+@@ -849,11 +849,16 @@ class MuxerUnifiedComplete extends UrlbarMuxer {
+       result.providerName == "UrlbarProviderHeuristicFallback" &&
+       state.context.heuristicResult?.providerName !=
+         "UrlbarProviderHeuristicFallback"
+      && !(
+        result.type == UrlbarUtils.RESULT_TYPE.SEARCH &&
+        state.context.heuristicResult?.type == UrlbarUtils.RESULT_TYPE.URL
+      )
+     ) {
+       return false;
     }
 
     if (result.providerName == "UrlbarProviderTabToSearch") {
@@ -10,7 +19,7 @@ index c12d875172650dddfe7de623a776149517c83302..66e923ed2c84e350dd7ba7a20e362666
       // Discard the result if a tab-to-search result was added already.
       if (!state.canAddTabToSearch) {
         return false;
-@@ -1500,7 +1501,9 @@ class MuxerUnifiedComplete extends UrlbarMuxer {
+@@ -1500,7 +1505,9 @@ class MuxerUnifiedComplete extends UrlbarMuxer {
       usedLimits.maxResultCount++;
     }
 
--- a/src/browser/components/urlbar/UrlbarProviderHeuristicFallback-sys-mjs.patch
+++ b/src/browser/components/urlbar/UrlbarProviderHeuristicFallback-sys-mjs.patch
@@ -0,0 +1,42 @@
+diff --git a/browser/components/urlbar/UrlbarProviderHeuristicFallback.sys.mjs b/browser/components/urlbar/UrlbarProviderHeuristicFallback.sys.mjs
+index 7a60a871022df44c0d26745f0035fce988cc5f92..0b89f9b66573d4c5ffb67983d728bb593e5cb524 100644
+--- a/browser/components/urlbar/UrlbarProviderHeuristicFallback.sys.mjs
+++ b/browser/components/urlbar/UrlbarProviderHeuristicFallback.sys.mjs
+@@ -75,22 +75,26 @@ export class UrlbarProviderHeuristicFallback extends UrlbarProvider {
+         // Since we can't tell if this is a real URL and whether the user wants
+         // to visit or search for it, we provide an alternative searchengine
+         // match if the string looks like an alphanumeric origin or an e-mail.
+-        let str = queryContext.searchString;
+-        if (!URL.canParse(str)) {
+-          if (
+-            lazy.UrlbarPrefs.get("keyword.enabled") &&
+-            (lazy.UrlUtils.looksLikeOrigin(str, {
+-              noIp: true,
+-              noPort: true,
+-            }) ||
+-              lazy.UrlUtils.REGEXP_COMMON_EMAIL.test(str))
+-          ) {
+        let trimmedSearchString = queryContext.trimmedSearchString;
+        let [searchCandidate] = UrlbarUtils.stripPrefixAndTrim(
+          trimmedSearchString,
+          {
+            trimSlash: true,
+           }
+        );
+        if (
+          lazy.UrlbarPrefs.get("keyword.enabled") &&
+          (lazy.UrlUtils.looksLikeUrl(searchCandidate) ||
+            lazy.UrlUtils.looksLikeOrigin(searchCandidate, {
+              allowPartialNumericalTLDs: true,
+            }) !== lazy.UrlUtils.LOOKS_LIKE_ORIGIN.NONE ||
+            lazy.UrlUtils.REGEXP_COMMON_EMAIL.test(trimmedSearchString))
+        ) {
+             let searchResult = await this._engineSearchResult({ queryContext });
+             if (instance != this.queryInstance) {
+               return;
+             }
+             addCallback(this, searchResult);
+-          }
+         }
+         return;
+       }
--- a/src/browser/components/urlbar/UrlbarUtils-sys-mjs.patch
+++ b/src/browser/components/urlbar/UrlbarUtils-sys-mjs.patch
@@ -1,5 +1,5 @@
 diff --git a/browser/components/urlbar/UrlbarUtils.sys.mjs b/browser/components/urlbar/UrlbarUtils.sys.mjs
-index b97fa81cef276e4bb22414b7c182e00b4bb835dc..1f489eceead0aa331ace59281cb777db5e635366 100644
+index a4ed35032c0c60f230d95f451b3f615232784cad..2c92860acb2ddc9829eef006d93431e871241c3a 100644
 --- a/browser/components/urlbar/UrlbarUtils.sys.mjs
 +++ b/browser/components/urlbar/UrlbarUtils.sys.mjs
@@ -81,6 +81,7 @@ export var UrlbarUtils = {
--- a/src/browser/components/urlbar/content/UrlbarInput-mjs.patch
+++ b/src/browser/components/urlbar/content/UrlbarInput-mjs.patch
@@ -1,5 +1,5 @@
 diff --git a/browser/components/urlbar/content/UrlbarInput.mjs b/browser/components/urlbar/content/UrlbarInput.mjs
-index edb0482f0bfb22c70a585b0770e5b0437983779e..545f65db4fe8b807b388d5552842cd9e56a72eb3 100644
+index edb0482f0bfb22c70a585b0770e5b0437983779e..109e9eb18b90c650caff1287caef04dce857e122 100644
 --- a/browser/components/urlbar/content/UrlbarInput.mjs
 +++ b/browser/components/urlbar/content/UrlbarInput.mjs
@@ -68,6 +68,13 @@ const lazy = XPCOMUtils.declareLazy({
@@ -122,14 +122,17 @@ index edb0482f0bfb22c70a585b0770e5b0437983779e..545f65db4fe8b807b388d5552842cd9e
     // Enable the animation only after the first extend call to ensure it
     // doesn't run when opening a new window.
     if (!this.hasAttribute("breakout-extend-animate")) {
-@@ -2562,6 +2627,24 @@ export class UrlbarInput extends HTMLElement {
+@@ -2562,6 +2627,27 @@ export class UrlbarInput extends HTMLElement {
       return;
     }
 
 +    if (this._zenHandleUrlbarClose) {
 +      this._zenHandleUrlbarClose();
+    } else if (!this._untrimmedValue) {
+      // Restore the current page URL when the urlbar is empty on blur
+      this.handleRevert();
 +    }
-+    
+
 +    // Arc like URLbar: Blur the input on exit
 +    const zenToolbox = this.document.getElementById("navigator-toolbox");
 +    this.window.document.documentElement.setAttribute("supress-primary-adjustment", !(
@@ -147,7 +150,7 @@ index edb0482f0bfb22c70a585b0770e5b0437983779e..545f65db4fe8b807b388d5552842cd9e
     this.removeAttribute("breakout-extend");
     this.#updateTextboxPosition();
   }
-@@ -2592,7 +2675,7 @@ export class UrlbarInput extends HTMLElement {
+@@ -2592,7 +2678,7 @@ export class UrlbarInput extends HTMLElement {
     forceUnifiedSearchButtonAvailable = false
   ) {
     let prevState = this.getAttribute("pageproxystate");
@@ -156,7 +159,7 @@ index edb0482f0bfb22c70a585b0770e5b0437983779e..545f65db4fe8b807b388d5552842cd9e
     this.setAttribute("pageproxystate", state);
     this._inputContainer.setAttribute("pageproxystate", state);
     this._identityBox?.setAttribute("pageproxystate", state);
-@@ -2846,10 +2929,12 @@ export class UrlbarInput extends HTMLElement {
+@@ -2846,10 +2932,12 @@ export class UrlbarInput extends HTMLElement {
       return;
     }
     this.style.top = px(
@@ -169,7 +172,7 @@ index edb0482f0bfb22c70a585b0770e5b0437983779e..545f65db4fe8b807b388d5552842cd9e
     );
   }
 
-@@ -2908,9 +2993,10 @@ export class UrlbarInput extends HTMLElement {
+@@ -2908,9 +2996,10 @@ export class UrlbarInput extends HTMLElement {
           return;
         }
 
@@ -181,7 +184,7 @@ index edb0482f0bfb22c70a585b0770e5b0437983779e..545f65db4fe8b807b388d5552842cd9e
         );
         this.style.setProperty(
           "--urlbar-height",
-@@ -3344,6 +3430,7 @@ export class UrlbarInput extends HTMLElement {
+@@ -3344,6 +3433,7 @@ export class UrlbarInput extends HTMLElement {
   }
 
   _toggleActionOverride(event) {
@@ -189,7 +192,7 @@ index edb0482f0bfb22c70a585b0770e5b0437983779e..545f65db4fe8b807b388d5552842cd9e
     if (
       event.keyCode == KeyEvent.DOM_VK_SHIFT ||
       event.keyCode == KeyEvent.DOM_VK_ALT ||
-@@ -3447,8 +3534,8 @@ export class UrlbarInput extends HTMLElement {
+@@ -3447,8 +3537,8 @@ export class UrlbarInput extends HTMLElement {
     if (!this.#isAddressbar) {
       return val;
     }
@@ -200,7 +203,7 @@ index edb0482f0bfb22c70a585b0770e5b0437983779e..545f65db4fe8b807b388d5552842cd9e
       : val;
     // Only trim value if the directionality doesn't change to RTL and we're not
     // showing a strikeout https protocol.
-@@ -3754,6 +3841,7 @@ export class UrlbarInput extends HTMLElement {
+@@ -3754,6 +3844,7 @@ export class UrlbarInput extends HTMLElement {
     resultDetails = null,
     browser = this.window.gBrowser.selectedBrowser
   ) {
@@ -208,7 +211,7 @@ index edb0482f0bfb22c70a585b0770e5b0437983779e..545f65db4fe8b807b388d5552842cd9e
     if (this.#isAddressbar) {
       this.#prepareAddressbarLoad(
         url,
-@@ -3861,6 +3949,10 @@ export class UrlbarInput extends HTMLElement {
+@@ -3861,6 +3952,10 @@ export class UrlbarInput extends HTMLElement {
       }
       reuseEmpty = true;
     }
@@ -219,7 +222,7 @@ index edb0482f0bfb22c70a585b0770e5b0437983779e..545f65db4fe8b807b388d5552842cd9e
     if (
       where == "tab" &&
       reuseEmpty &&
-@@ -3868,6 +3960,9 @@ export class UrlbarInput extends HTMLElement {
+@@ -3868,6 +3963,9 @@ export class UrlbarInput extends HTMLElement {
     ) {
       where = "current";
     }
@@ -229,7 +232,7 @@ index edb0482f0bfb22c70a585b0770e5b0437983779e..545f65db4fe8b807b388d5552842cd9e
     return where;
   }
 
-@@ -4122,6 +4217,7 @@ export class UrlbarInput extends HTMLElement {
+@@ -4122,6 +4220,7 @@ export class UrlbarInput extends HTMLElement {
       this.setResultForCurrentValue(null);
       this.handleCommand();
       this.controller.clearLastQueryContextCache();
@@ -237,7 +240,7 @@ index edb0482f0bfb22c70a585b0770e5b0437983779e..545f65db4fe8b807b388d5552842cd9e
 
       this._suppressStartQuery = false;
     });
-@@ -4129,7 +4225,6 @@ export class UrlbarInput extends HTMLElement {
+@@ -4129,7 +4228,6 @@ export class UrlbarInput extends HTMLElement {
     contextMenu.addEventListener("popupshowing", () => {
       // Close the results pane when the input field contextual menu is open,
       // because paste and go doesn't want a result selection.
@@ -245,7 +248,7 @@ index edb0482f0bfb22c70a585b0770e5b0437983779e..545f65db4fe8b807b388d5552842cd9e
 
       let controller =
         this.document.commandDispatcher.getControllerForCommand("cmd_paste");
-@@ -4239,7 +4334,11 @@ export class UrlbarInput extends HTMLElement {
+@@ -4239,7 +4337,11 @@ export class UrlbarInput extends HTMLElement {
     if (!engineName && !source && !this.hasAttribute("searchmode")) {
       return;
     }
@@ -258,7 +261,7 @@ index edb0482f0bfb22c70a585b0770e5b0437983779e..545f65db4fe8b807b388d5552842cd9e
     if (this._searchModeIndicatorTitle) {
       this._searchModeIndicatorTitle.textContent = "";
       this._searchModeIndicatorTitle.removeAttribute("data-l10n-id");
-@@ -4549,6 +4648,7 @@ export class UrlbarInput extends HTMLElement {
+@@ -4549,6 +4651,7 @@ export class UrlbarInput extends HTMLElement {
 
     this.document.l10n.setAttributes(
       this.inputField,
@@ -266,7 +269,7 @@ index edb0482f0bfb22c70a585b0770e5b0437983779e..545f65db4fe8b807b388d5552842cd9e
       l10nId,
       l10nId == "urlbar-placeholder-with-name"
         ? { name: engineName }
-@@ -4662,6 +4762,11 @@ export class UrlbarInput extends HTMLElement {
+@@ -4662,6 +4765,11 @@ export class UrlbarInput extends HTMLElement {
   }
 
   _on_click(event) {
@@ -278,7 +281,7 @@ index edb0482f0bfb22c70a585b0770e5b0437983779e..545f65db4fe8b807b388d5552842cd9e
     switch (event.target) {
       case this.inputField:
       case this._inputContainer:
-@@ -4740,7 +4845,7 @@ export class UrlbarInput extends HTMLElement {
+@@ -4740,7 +4848,7 @@ export class UrlbarInput extends HTMLElement {
       }
     }
 
@@ -287,7 +290,7 @@ index edb0482f0bfb22c70a585b0770e5b0437983779e..545f65db4fe8b807b388d5552842cd9e
       this.view.autoOpen({ event });
     } else {
       if (this._untrimOnFocusAfterKeydown) {
-@@ -4780,9 +4885,16 @@ export class UrlbarInput extends HTMLElement {
+@@ -4780,9 +4888,16 @@ export class UrlbarInput extends HTMLElement {
   }
 
   _on_mousedown(event) {
@@ -305,7 +308,7 @@ index edb0482f0bfb22c70a585b0770e5b0437983779e..545f65db4fe8b807b388d5552842cd9e
         if (
           event.composedTarget != this.inputField &&
           event.composedTarget != this._inputContainer
-@@ -4792,6 +4904,10 @@ export class UrlbarInput extends HTMLElement {
+@@ -4792,6 +4907,10 @@ export class UrlbarInput extends HTMLElement {
 
         this.focusedViaMousedown = !this.focused;
         this._preventClickSelectsAll = this.focused;
@@ -316,7 +319,7 @@ index edb0482f0bfb22c70a585b0770e5b0437983779e..545f65db4fe8b807b388d5552842cd9e
 
         // Keep the focus status, since the attribute may be changed
         // upon calling this.focus().
-@@ -4827,7 +4943,7 @@ export class UrlbarInput extends HTMLElement {
+@@ -4827,7 +4946,7 @@ export class UrlbarInput extends HTMLElement {
         }
         // Don't close the view when clicking on a tab; we may want to keep the
         // view open on tab switch, and the TabSelect event arrived earlier.
@@ -325,7 +328,7 @@ index edb0482f0bfb22c70a585b0770e5b0437983779e..545f65db4fe8b807b388d5552842cd9e
           break;
         }
 
-@@ -5155,7 +5271,7 @@ export class UrlbarInput extends HTMLElement {
+@@ -5155,7 +5274,7 @@ export class UrlbarInput extends HTMLElement {
     // When we are in actions search mode we can show more results so
     // increase the limit.
     let maxResults =
--- a/src/browser/extensions/newtab/lib/ActivityStream-sys-mjs.patch
+++ b/src/browser/extensions/newtab/lib/ActivityStream-sys-mjs.patch
@@ -1,5 +1,5 @@
 diff --git a/browser/extensions/newtab/lib/ActivityStream.sys.mjs b/browser/extensions/newtab/lib/ActivityStream.sys.mjs
-index ae3c01650b3023a692cd4c50e33e3c3c39770c47..27a5fb0a630b9b79566be08cd5f7c9466ca30381 100644
+index 0f73c33c3237413131a2f4d2d1f3be857e533437..d7e9fcadc7744651fbe14952589df4603e7db592 100644
 --- a/browser/extensions/newtab/lib/ActivityStream.sys.mjs
 +++ b/browser/extensions/newtab/lib/ActivityStream.sys.mjs
@@ -295,7 +295,7 @@ export const PREFS_CONFIG = new Map([
--- a/src/browser/themes/shared/zen-icons/icons.css
+++ b/src/browser/themes/shared/zen-icons/icons.css
@@ -485,7 +485,7 @@
 }

 #zen-site-data-icon-button {
-  padding: 0 6px !important;
+  padding: 0 4px !important;
  border-radius: var(--urlbar-icon-border-radius) !important;

  & image {
--- a/src/external-patches/firefox/.gitkeep
+++ b/src/external-patches/firefox/.gitkeep
--- a/src/external-patches/firefox/README.md
+++ b/src/external-patches/firefox/README.md
--- a/src/external-patches/firefox/fix_macos_crash_on_shutdown_firefox_149.patch
+++ b/src/external-patches/firefox/fix_macos_crash_on_shutdown_firefox_149.patch
--- a/src/external-patches/firefox/no_liquid_glass_icon.patch
+++ b/src/external-patches/firefox/no_liquid_glass_icon.patch
--- a/src/external-patches/librewolf/README.md
+++ b/src/external-patches/librewolf/README.md
@@ -0,0 +1,3 @@
+# Patches imported from LibreWolf
+
+Firefox sometimes makes changes without considering the impact on forks. This is the case of the patches that are imported from LibreWolf, which are already present in LibreWolf but not yet (or never) present in Firefox. Thanks to LibreWolf for making these patches available and for their work in maintaining them. We will keep these patches as long as they are needed, and we will remove them once they are no longer necessary (for example, when they are merged into Firefox or when the issue they solve is no longer present).
--- a/src/external-patches/librewolf/firefox-in-ua.patch
+++ b/src/external-patches/librewolf/firefox-in-ua.patch
@@ -0,0 +1,12 @@
+diff --git a/toolkit/moz.configure b/toolkit/moz.configure
+--- a/toolkit/moz.configure
+++ b/toolkit/moz.configure
+@@ -28,7 +28,7 @@ project_flag(
+ 
+ project_flag(
+     env="MOZ_APP_UA_NAME",
+-    default="",
+    default="Firefox",
+     nargs=1,
+     help="Application name in the User Agent string",
+ )
--- a/src/external-patches/manifest.json
+++ b/src/external-patches/manifest.json
@@ -0,0 +1,24 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+[
+  {
+    "type": "phabricator",
+    "id": "D279007",
+    "name": "Fix MacOS Crash on Shutdown Firefox 149"
+  },
+  {
+    "type": "local",
+    "path": "firefox/no_liquid_glass_icon.patch"
+  },
+  {
+    "type": "patch",
+    "url": "https://codeberg.org/librewolf/source/raw/branch/main/patches/firefox-in-ua.patch",
+    "dest": "librewolf",
+    "replaces": {
+      // They don't correctly export this patch, so we need to replace
+      // the parameter's help description with the correct one.
+      "application": "Application"
+    }
+  }
+]
--- a/src/layout/generic/nsIFrame-cpp.patch
+++ b/src/layout/generic/nsIFrame-cpp.patch
@@ -1,8 +1,8 @@
 diff --git a/layout/generic/nsIFrame.cpp b/layout/generic/nsIFrame.cpp
-index c0ca05afc1e8eb5cb7115a22c39dcf45285fdfb7..84b3fec2c7b2bc671e7004d8571dc428b8ee011d 100644
+index 2c4aca4a5984fc3201a2c643f8d26b8c4f4ef3bd..4c21cee90e5442d45cdb2bcf3f91200f0441218f 100644
 --- a/layout/generic/nsIFrame.cpp
 +++ b/layout/generic/nsIFrame.cpp
-@@ -11958,6 +11958,11 @@ gfx::Matrix nsIFrame::ComputeWidgetTransform() const {
+@@ -11956,6 +11956,11 @@ gfx::Matrix nsIFrame::ComputeWidgetTransform() const {
   gfx::Matrix4x4 matrix = nsStyleTransformMatrix::ReadTransforms(
       uiReset->mMozWindowTransform, refBox, float(appUnitsPerDevPixel));
 
--- a/src/layout/style/nsStyleStruct-cpp.patch
+++ b/src/layout/style/nsStyleStruct-cpp.patch
@@ -1,8 +1,8 @@
 diff --git a/layout/style/nsStyleStruct.cpp b/layout/style/nsStyleStruct.cpp
-index 3c84ea049b01c20c6a7e9ff717e19d1d9e86248b..ed6b15dffa571348d1c13bf31f3b2e1638151e8f 100644
+index 25357c6a506b969c5049190c29e4e411ee5f4c31..bef909ddfc28d084cf87cae3fbd050bbde21468d 100644
 --- a/layout/style/nsStyleStruct.cpp
 +++ b/layout/style/nsStyleStruct.cpp
-@@ -3217,6 +3217,9 @@ nsStyleUIReset::nsStyleUIReset()
+@@ -3270,6 +3270,9 @@ nsStyleUIReset::nsStyleUIReset()
       mWindowShadow(StyleWindowShadow::Auto),
       mWindowOpacity(1.0),
       mMozWindowInputRegionMargin(StyleLength::Zero()),
@@ -12,7 +12,7 @@ index 3c84ea049b01c20c6a7e9ff717e19d1d9e86248b..ed6b15dffa571348d1c13bf31f3b2e16
       mTransitions(
           nsStyleAutoArray<StyleTransition>::WITH_SINGLE_INITIAL_ELEMENT),
       mTransitionTimingFunctionCount(1),
-@@ -3261,6 +3264,7 @@ nsStyleUIReset::nsStyleUIReset(const nsStyleUIReset& aSource)
+@@ -3314,6 +3317,7 @@ nsStyleUIReset::nsStyleUIReset(const nsStyleUIReset& aSource)
       mWindowOpacity(aSource.mWindowOpacity),
       mMozWindowInputRegionMargin(aSource.mMozWindowInputRegionMargin),
       mMozWindowTransform(aSource.mMozWindowTransform),
--- a/src/layout/style/nsStyleStruct-h.patch
+++ b/src/layout/style/nsStyleStruct-h.patch
@@ -1,8 +1,8 @@
 diff --git a/layout/style/nsStyleStruct.h b/layout/style/nsStyleStruct.h
-index 20d0dc30020ee7fcd27f689cb6c0754224b003c5..dcca0efd2c9822937c994dffeb63d2263fbb6331 100644
+index ca11ab168761a6da23811d802a87f6c31af6cca9..cb74679626620a12d37fb1671c373ea9793ae004 100644
 --- a/layout/style/nsStyleStruct.h
 +++ b/layout/style/nsStyleStruct.h
-@@ -2080,6 +2080,7 @@ struct MOZ_NEEDS_MEMMOVABLE_MEMBERS nsStyleUIReset {
+@@ -2094,6 +2094,7 @@ struct MOZ_NEEDS_MEMMOVABLE_MEMBERS nsStyleUIReset {
   // The margin of the window region that should be transparent to events.
   mozilla::StyleLength mMozWindowInputRegionMargin;
   mozilla::StyleTransform mMozWindowTransform;
--- a/src/modules/libpref/init/StaticPrefList-yaml.patch
+++ b/src/modules/libpref/init/StaticPrefList-yaml.patch
@@ -1,8 +1,8 @@
 diff --git a/modules/libpref/init/StaticPrefList.yaml b/modules/libpref/init/StaticPrefList.yaml
-index cc7fd419035a972bfab1b0e7631b8856e846ce81..b4e6d699f99e7164e62ce20792919420a8e73810 100644
+index 0986e53121fdb821bca4a7c30ff707bfdf2dbad7..2a1865098a00282aa1839df245cb472cdd64fdec 100644
 --- a/modules/libpref/init/StaticPrefList.yaml
 +++ b/modules/libpref/init/StaticPrefList.yaml
-@@ -19738,6 +19738,7 @@
+@@ -19748,6 +19748,7 @@
   mirror: always
 #endif
 
--- a/src/netwerk/protocol/http/moz-build.patch
+++ b/src/netwerk/protocol/http/moz-build.patch
@@ -1,13 +0,0 @@
-diff --git a/netwerk/protocol/http/moz.build b/netwerk/protocol/http/moz.build
-index d2330003caf35c43d6831fb0d356ece513906f78..76c2faf822ddaf645eb03d93380c58b4e3b510c0 100644
--- a/netwerk/protocol/http/moz.build
-+++ b/netwerk/protocol/http/moz.build
-@@ -227,7 +227,7 @@ LOCAL_INCLUDES += [
-     "/netwerk/url-classifier",
- ]
- 
-DEFINES["MOZ_APP_UA_NAME"] = f'"{CONFIG["MOZ_APP_UA_NAME"]}"'
-+DEFINES["MOZ_APP_UA_NAME"] = f'"Firefox"'
- 
- if CONFIG["MOZ_AUTH_EXTENSION"]:
-     LOCAL_INCLUDES += [
--- a/src/toolkit/components/extensions/parent/ext-runtime-js.patch
+++ b/src/toolkit/components/extensions/parent/ext-runtime-js.patch
@@ -1,5 +1,5 @@
 diff --git a/toolkit/components/extensions/parent/ext-runtime.js b/toolkit/components/extensions/parent/ext-runtime.js
-index 0d7a3e505b6bd30548c6dda1504dd343a517b083..54400def5e02e886765fab68c3854a6b3c24ef2b 100644
+index 0d7a3e505b6bd30548c6dda1504dd343a517b083..fb6c6b4ef3eae24995a02f708ec41afd31d812ef 100644
 --- a/toolkit/components/extensions/parent/ext-runtime.js
 +++ b/toolkit/components/extensions/parent/ext-runtime.js
@@ -333,7 +333,7 @@ this.runtime = class extends ExtensionAPIPersistent {
@@ -7,7 +7,7 @@ index 0d7a3e505b6bd30548c6dda1504dd343a517b083..54400def5e02e886765fab68c3854a6b
         getBrowserInfo: function () {
           const { name, vendor, version, appBuildID } = Services.appinfo;
 -          const info = { name, vendor, version, buildID: appBuildID };
-+          const info = { name: 'firefox', vendor, version: AppConstants.ZEN_FIREFOX_VERSION, buildID: appBuildID };
+          const info = { name: 'Firefox', vendor, version: AppConstants.ZEN_FIREFOX_VERSION, buildID: appBuildID, zen: {version: AppConstants.MOZ_APP_VERSION_DISPLAY} };
           return Promise.resolve(info);
         },
 
--- a/src/toolkit/modules/AppConstants-sys-mjs.patch
+++ b/src/toolkit/modules/AppConstants-sys-mjs.patch
@@ -1,8 +1,8 @@
 diff --git a/toolkit/modules/AppConstants.sys.mjs b/toolkit/modules/AppConstants.sys.mjs
-index 5465ed3fb01e4214029b44f338d5e1e1580c3aab..a4d6b42916014d5e0f643b35a7b4feb281f59023 100644
+index e2a22ddd6c6ba36491f37ed22bc2e1fbc149790c..920d8649ef48d685891223a834110ad9a059001a 100644
 --- a/toolkit/modules/AppConstants.sys.mjs
 +++ b/toolkit/modules/AppConstants.sys.mjs
-@@ -172,6 +172,8 @@ export var AppConstants = Object.freeze({
+@@ -170,6 +170,8 @@ export var AppConstants = Object.freeze({
   MOZ_UPDATE_CHANNEL: "@MOZ_UPDATE_CHANNEL@",
   MOZ_WIDGET_TOOLKIT: "@MOZ_WIDGET_TOOLKIT@",
 
--- a/src/toolkit/modules/moz-build.patch
+++ b/src/toolkit/modules/moz-build.patch
@@ -1,5 +1,5 @@
 diff --git a/toolkit/modules/moz.build b/toolkit/modules/moz.build
-index abc630955c18de629d3ffff3e8f9aa29f57950be..97d6d5f25d0859684c405c659e0eef26007027c4 100644
+index 114a8c3e2e36e57cb2334a893a11f1619831a6e7..9c9ae37b6462d00c93d8f3319cea2960b3cd9816 100644
 --- a/toolkit/modules/moz.build
 +++ b/toolkit/modules/moz.build
@@ -281,6 +281,7 @@ for var in (
--- a/src/toolkit/xre/nsXREDirProvider-cpp.patch
+++ b/src/toolkit/xre/nsXREDirProvider-cpp.patch
@@ -0,0 +1,40 @@
+diff --git a/toolkit/xre/nsXREDirProvider.cpp b/toolkit/xre/nsXREDirProvider.cpp
+index 5eae0bca990fea9e995bd2edf5e879361f89391c..3f8bfedb83ddae07b1e82715fc7f6b2109a39e33 100644
+--- a/toolkit/xre/nsXREDirProvider.cpp
+++ b/toolkit/xre/nsXREDirProvider.cpp
+@@ -1322,9 +1322,11 @@ nsresult nsXREDirProvider::AppendFromAppData(nsIFile* aFile, bool aIsDotted) {
+   // Similar to nsXREDirProvider::AppendProfilePath.
+   // TODO: Bug 1990407 - Evaluate if refactoring might be required there in the
+   // future?
+-  if (gAppData->profile) {
+  // Use aIsDotted for a different purpose here, will probably break in the future
+  if (gAppData->profile && aIsDotted) {
+     nsAutoCString profile;
+     profile = gAppData->profile;
+    profile = "."_ns + nsDependentCString(gAppData->profile);
+     MOZ_TRY(aFile->AppendRelativeNativePath(profile));
+   } else {
+     nsAutoCString vendor;
+@@ -1334,8 +1336,6 @@ nsresult nsXREDirProvider::AppendFromAppData(nsIFile* aFile, bool aIsDotted) {
+     ToLowerCase(vendor);
+     ToLowerCase(appName);
+ 
+-    MOZ_TRY(aFile->AppendRelativeNativePath(aIsDotted ? ("."_ns + vendor)
+-                                                      : vendor));
+     MOZ_TRY(aFile->AppendRelativeNativePath(appName));
+   }
+ 
+@@ -1503,13 +1503,8 @@ nsresult nsXREDirProvider::GetLegacyOrXDGHomePath(const char* aHomeDir,
+ 
+     // If the build was made against a specific profile name, MOZ_APP_PROFILE=
+     // then make sure we respect this and dont move to XDG directory
+-    if (gAppData->profile) {
+-      MOZ_TRY(NS_NewNativeLocalFile(nsDependentCString(aHomeDir),
+-                                    getter_AddRefs(localDir)));
+-    } else {
+       MOZ_TRY(GetLegacyOrXDGConfigHome(aHomeDir, getter_AddRefs(localDir)));
+       MOZ_TRY(localDir->Clone(getter_AddRefs(parentDir)));
+-    }
+ 
+     MOZ_TRY(AppendFromAppData(localDir, false));
+   }
--- a/src/zen/common/jar.inc.mn
+++ b/src/zen/common/jar.inc.mn
@@ -25,7 +25,7 @@
        content/browser/zen-styles/zen-panel-ui.css                             (../../zen/common/styles/zen-panel-ui.css)
        content/browser/zen-styles/zen-single-components.css                    (../../zen/common/styles/zen-single-components.css)
        content/browser/zen-styles/zen-sidebar.css                              (../../zen/common/styles/zen-sidebar.css)
-        content/browser/zen-styles/zen-toolbar.css                              (../../zen/common/styles/zen-toolbar.css)
+*       content/browser/zen-styles/zen-toolbar.css                              (../../zen/common/styles/zen-toolbar.css)
        content/browser/zen-styles/zen-browser-container.css                    (../../zen/common/styles/zen-browser-container.css)
        content/browser/zen-styles/zen-omnibox.css                              (../../zen/common/styles/zen-omnibox.css)
        content/browser/zen-styles/zen-popup.css                                (../../zen/common/styles/zen-popup.css)
--- a/src/zen/common/modules/ZenMenubar.mjs
+++ b/src/zen/common/modules/ZenMenubar.mjs
@@ -112,7 +112,7 @@ export class nsZenMenuBar {
    const openUnsyncedWindowItem = window.MozXULElement.parseXULToFragment(
      `<toolbarbutton id="appMenu-new-zen-unsynced-window-button"
                class="subviewbutton"
-                data-l10n-id="zen-menubar-new-unsynced-window"
+                data-l10n-id="zen-appmenu-new-blank-window"
                key="zen-new-unsynced-window"
                command="cmd_zenNewNavigatorUnsynced"/>`
    ).querySelector("toolbarbutton");
@@ -123,7 +123,7 @@ export class nsZenMenuBar {
      window.MozXULElement.parseXULToFragment(`
        <menuitem id="menu_new_zen_unsynced_window"
                class="subviewbutton"
-                data-l10n-id="zen-menubar-new-unsynced-window"
+                data-l10n-id="zen-menubar-new-blank-window"
                key="zen-new-unsynced-window"
                command="cmd_zenNewNavigatorUnsynced"/>`)
    );
--- a/src/zen/common/modules/ZenUIManager.mjs
+++ b/src/zen/common/modules/ZenUIManager.mjs
@@ -1055,7 +1055,7 @@ window.gZenVerticalTabsManager = {
        if (!this._hasSetSingleToolbar) {
          height = AppConstants.platform == "macosx" ? 34 : 32;
        } else if (gURLBar.getAttribute("breakout-extend") !== "true") {
-          height = 40;
+          height = 38;
        }
        if (typeof height !== "undefined") {
          gURLBar.style.setProperty("--urlbar-height", `${height}px`);
@@ -1275,6 +1275,15 @@ window.gZenVerticalTabsManager = {
        appContentNavbarContaienr.append(windowButtons);
      }

+      if (
+        this._hasSetSingleToolbar &&
+        Services.prefs.getBoolPref("zen.view.overflow-webext-toolbar", true)
+      ) {
+        topButtons.setAttribute("addon-webext-overflowtarget", "zen-overflow-extensions-list");
+      } else {
+        topButtons.setAttribute("addon-webext-overflowtarget", "overflowed-extensions-list");
+      }
+
      gZenCompactModeManager.updateCompactModeContext(isSingleToolbar);

      // Always move the splitter next to the sidebar
--- a/src/zen/common/styles/zen-omnibox.css
+++ b/src/zen/common/styles/zen-omnibox.css
@@ -80,7 +80,7 @@

 #urlbar:not([breakout-extend="true"]) {
  &:hover .urlbar-background {
-    background-color: light-dark(rgba(0, 0, 0, 0.1), rgba(255, 255, 255, 0.2)) !important;
+    background-color: var(--zen-toolbar-element-bg-hover) !important;
  }
 }

@@ -209,7 +209,7 @@
  margin: 0;

  :root[zen-single-toolbar="true"] & {
-    padding: 6px !important;
+    padding: 5px !important;
    width: unset !important;
    height: unset !important;
  }
@@ -396,7 +396,7 @@
 #urlbar #tracking-protection-icon-container,
 #urlbar:not([breakout-extend="true"]) #identity-box:is(:not(.chromeUI), [pageproxystate="invalid"]) #identity-icon-box {
  border-radius: var(--urlbar-icon-border-radius) !important;
-  min-width: 28px;
+  min-width: 26px;
 }

 /* Notification Stack */
@@ -649,7 +649,7 @@
  }

  &[selected] {
-    --zen-selected-bg: color-mix(in srgb, var(--zen-primary-color) 50%, light-dark(rgba(0, 0, 0, 0.5), rgba(255, 255, 255, 0.2)) 50%);
+    --zen-selected-bg: color-mix(in srgb, var(--zen-primary-color) 55%, light-dark(rgba(0, 0, 0, 0.5), rgba(255, 255, 255, 0.2)) 50%);
    --zen-selected-color: color-mix(in srgb, var(--zen-selected-bg), black 30%);
    background-color: var(--zen-selected-bg) !important;

@@ -667,7 +667,7 @@
      color: var(--zen-selected-color) !important;
    }

-    &:is([type="switchtab"], [type="dynamic"]) .urlbarView-favicon,
+    &:is([type="switchtab"], [type="dynamic"], [type="history_serp"], [type="autofill_origin"], [type="top_site"]) .urlbarView-favicon,
    & .urlbarView-shortcutContent {
      fill: var(--zen-selected-color) !important;
      background-color: rgba(255, 255, 255, 0.9) !important;
--- a/src/zen/common/styles/zen-overflowing-addons.css
+++ b/src/zen/common/styles/zen-overflowing-addons.css
@@ -0,0 +1,48 @@
+/*
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#zen-overflow-extensions-list:not(:empty) {
+  --uei-icon-size: 14px;
+  display: flex;
+  gap: 8px;
+  padding: 8px 2px;
+  padding-bottom: 0px;
+
+  & .unified-extensions-item {
+    flex: 1;
+    margin: 0;
+  }
+
+  & .toolbarbutton-badge-stack {
+    margin: 0;
+    width: 100%;
+    height: 100%;
+    padding: 8px 0;
+    justify-content: center;
+    align-items: center;
+  }
+
+  & .unified-extensions-item-action-button {
+    background-color: var(--zen-toolbar-element-bg);
+    height: 30px;
+    margin: 0;
+    justify-content: center;
+    align-items: center;
+    border-radius: var(--border-radius-medium);
+    overflow: clip;
+    padding: 0;
+
+    &:hover {
+      background-color: var(--zen-toolbar-element-bg-hover);
+    }
+  }
+
+  .unified-extensions-item-contents,
+  .unified-extensions-item-menu-button,
+  unified-extensions-item-messagebar-wrapper {
+    display: none;
+  }
+}
--- a/src/zen/common/styles/zen-single-components.css
+++ b/src/zen/common/styles/zen-single-components.css
@@ -172,11 +172,14 @@
  }
 }

-.toolbarbutton-1:not(#tabs-newtab-button) {
+.toolbarbutton-1:not(#tabs-newtab-button),
+.urlbar-page-action,
+.identity-box-button {
  --tab-border-radius: 6px;
  --toolbarbutton-border-radius: var(--tab-border-radius);
  --toolbarbutton-inner-padding: 6px;
-  --toolbarbutton-outer-padding: 2px;
+  --toolbarbutton-outer-padding: 1px;
+  color: color-mix(in srgb, currentColor 60%, transparent);

  transition:
    background-color 0.1s,
@@ -381,6 +384,7 @@
    &:hover {
      background-color: color-mix(in srgb, currentColor 10%, transparent);
    }
+
    .zen-site-data-section:hover & {
      opacity: 0.5;
    }
@@ -536,7 +540,7 @@
          0px 2px 4px rgba(0, 0, 0, 0.1),
          inset 0px 1px 0px light-dark(transparent, rgba(255, 255, 255, 0.15));
        border-radius: 6px;
-        --base-border-color: light-dark(rgba(0, 0, 0, 0.175), rgba(255, 255, 255, 0.1));
+        --base-border-color: light-dark(rgba(0, 0, 0, 0.3), rgba(255, 255, 255, 0.1));
        border: 1px solid light-dark(var(--base-border-color), rgb(21, 21, 21));
      }

--- a/src/zen/common/styles/zen-theme.css
+++ b/src/zen/common/styles/zen-theme.css
@@ -141,14 +141,11 @@
  --zen-button-padding: 0.6rem 1.2rem;

  --zen-toolbar-element-bg: light-dark(
-    color-mix(in oklch, var(--toolbox-textcolor) 10%, transparent),
+    color-mix(in oklch, var(--toolbox-textcolor) 8%, transparent),
    color-mix(in oklch, var(--toolbox-textcolor) 15%, transparent)
  );

-  --zen-toolbar-element-bg-hover: light-dark(
-    color-mix(in srgb, var(--zen-toolbar-element-bg) 75%, transparent),
-    color-mix(in srgb, var(--zen-toolbar-element-bg) 60%, transparent)
-  );
+  --zen-toolbar-element-bg-hover: light-dark(rgba(0, 0, 0, 0.08), rgba(255, 255, 255, 0.1));

  /* Toolbar */
  --tab-selected-color-scheme: inherit !important;
@@ -222,7 +219,7 @@
  --input-border-color: var(--zen-input-border-color) !important;
  --zen-themed-toolbar-bg-transparent: light-dark(var(--zen-branding-bg), #171717);

-  --zen-workspace-indicator-height: 46px;
+  --zen-workspace-indicator-height: 44px;

  &:not([zen-sidebar-expanded='true']) {
    --zen-workspace-indicator-height: 38px;
@@ -231,10 +228,7 @@
  --toolbar-field-color: var(--toolbox-textcolor) !important;

  &[zen-private-window='true'] {
-    --zen-main-browser-background: linear-gradient(130deg,
-      color-mix(in srgb, rgb(10, 6, 11) 80%, var(--zen-themed-toolbar-bg-transparent)) 0%,
-      color-mix(in srgb, rgb(19, 7, 22) 80%, var(--zen-themed-toolbar-bg-transparent)) 100%
-    );
+    --zen-main-browser-background: color-mix(in srgb, rgb(11, 10, 11) 90%, var(--zen-themed-toolbar-bg-transparent));
    --zen-main-browser-background-toolbar: var(--zen-main-browser-background);
    --zen-primary-color: light-dark(rgb(93, 42, 107), rgb(110, 48, 125)) !important;
    --toolbox-textcolor: color-mix(in srgb, currentColor 95%, transparent) !important;
@@ -294,7 +288,7 @@
  }
 }

-#main-window:not([chromehidden~='toolbar']) {
+#main-window[windowtype="navigator:browser"]:not([chromehidden~='toolbar']) {
  min-height: 495px !important;

  @media (-moz-windows-mica) or (-moz-platform: macos) or ((-moz-platform: linux) and
--- a/src/zen/common/styles/zen-toolbar.css
+++ b/src/zen/common/styles/zen-toolbar.css
@@ -3,6 +3,7 @@
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */
+
 #nav-bar,
 #zen-sidebar-top-buttons {
  background: transparent;
@@ -11,3 +12,5 @@
 :root[inDOMFullscreen="true"] #zen-appcontent-navbar-wrapper {
  visibility: collapse;
 }
+
+%include zen-overflowing-addons.css
--- a/src/zen/common/sys/ZenCustomizableUI.sys.mjs
+++ b/src/zen/common/sys/ZenCustomizableUI.sys.mjs
@@ -121,8 +121,11 @@ export const ZenCustomizableUI = new (class {

  #initCreateNewButton(window) {
    const button = window.document.getElementById("zen-create-new-button");
-    button.addEventListener("command", (event) => {
-      if (window.gZenWorkspaces.privateWindowOrDisabled) {
+    // If we use "mousedown" event for private windows (which open a new tab on "click"), we might end up with
+    // the urlbar flicking and therefore we use "command" event to avoid that.
+    let isPrivateMode = window.gZenWorkspaces.privateWindowOrDisabled;
+    button.addEventListener(isPrivateMode ? "command" : "mousedown", (event) => {
+      if (isPrivateMode) {
        window.document.getElementById("cmd_newNavigatorTab").doCommand();
        return;
      }
--- a/src/zen/compact-mode/sidebar.inc.css
+++ b/src/zen/compact-mode/sidebar.inc.css
@@ -10,9 +10,14 @@
  }

  #zen-dragover-background {
-    width: calc(100% - var(--zen-toolbox-padding) * 2 - 5px);
+    width: calc(100% - var(--zen-toolbox-padding) * 2 - 7px);
    left: unset;
+    right: calc(var(--zen-toolbox-padding) + 3px);
    transform: translateY(-4px);
+
+    :root:not([zen-single-toolbar="true"]) & {
+      transform: translateY(calc(-100% - 2px));
+    }
  }

  #zen-tabbox-wrapper {
--- a/src/zen/drag-and-drop/ZenDragAndDrop.js
+++ b/src/zen/drag-and-drop/ZenDragAndDrop.js
@@ -936,7 +936,9 @@
      let dropElementFromEvent = event.target.closest(dropZoneSelector);
      dropElement = dropElementFromEvent || dropElement;
      if (!dropElementFromEvent) {
-        let hoveringPeriphery = !!event.target.closest("#tabbrowser-arrowscrollbox-periphery");
+        let hoveringPeriphery = !!event.target.closest(
+          ":is(#tabbrowser-arrowscrollbox-periphery, .pinned-tabs-container-separator)"
+        );
        if (event.target.classList.contains("zen-workspace-empty-space") || hoveringPeriphery) {
          let lastTab = gBrowser.tabs.at(-1);
          dropElement =
@@ -960,7 +962,8 @@
        dropElement = dragData.dropElement;
        dropBefore = dragData.dropBefore;
      }
-      if (!dropElement) {
+      // Essentials should be properly handled by ::animateVerticalPinnedGridDragOver
+      if (!dropElement || dropElement.hasAttribute("zen-essential")) {
        this.clearDragOverVisuals();
        return null;
      }
--- a/src/zen/folders/ZenFolder.mjs
+++ b/src/zen/folders/ZenFolder.mjs
@@ -21,7 +21,7 @@ export class nsZenFolder extends MozTabbrowserTabGroup {

  static rawIcon = new DOMParser().parseFromString(
    `
-      <svg width="28" height="28" viewBox="0 0 28 28" fill="none" xmlns="http://www.w3.org/2000/svg">
+      <svg width="28" height="28" viewBox="0 0 27 27" fill="none" xmlns="http://www.w3.org/2000/svg">
        <defs>
          <linearGradient gradientUnits="userSpaceOnUse" x1="14" y1="5.625" x2="14" y2="22.375" id="gradient-0">
            <stop offset="0" style="stop-color: rgb(255, 255, 255)"/>
@@ -242,7 +242,7 @@ export class nsZenFolder extends MozTabbrowserTabGroup {
  }

  get resetButton() {
-    return this.labelElement.parentElement.querySelector(".tab-reset-button");
+    return this.labelElement.parentElement?.querySelector(".tab-reset-button") ?? null;
  }

  unloadAllTabs(event) {
--- a/src/zen/folders/zen-folders.css
+++ b/src/zen/folders/zen-folders.css
@@ -98,6 +98,7 @@ zen-folder {

      & svg {
        filter: contrast(125%);
+        transform: translate(-1px, -1px);

        :root:not([zen-sidebar-expanded]) & {
          transition: transform 0.1s ease;
--- a/src/zen/glance/zen-glance.css
+++ b/src/zen/glance/zen-glance.css
@@ -34,7 +34,7 @@
    box-shadow: 0 0 12px 1px rgba(0, 0, 0, 0.07);
    padding: 8px;
    opacity: 1 !important;
-    color: var(--zen-primary-color);
+    color: var(--zen-primary-color) !important;

    &:hover {
      background: light-dark(rgb(41, 41, 41), rgb(204, 204, 204));
--- a/src/zen/sessionstore/ZenSessionManager.sys.mjs
+++ b/src/zen/sessionstore/ZenSessionManager.sys.mjs
@@ -10,7 +10,9 @@ const lazy = {};
 ChromeUtils.defineESModuleGetters(lazy, {
  PrivateBrowsingUtils: "resource://gre/modules/PrivateBrowsingUtils.sys.mjs",
  SessionStore: "resource:///modules/sessionstore/SessionStore.sys.mjs",
+  SessionStartup: "resource:///modules/sessionstore/SessionStartup.sys.mjs",
  gWindowSyncEnabled: "resource:///modules/zen/ZenWindowSync.sys.mjs",
+  gSyncOnlyPinnedTabs: "resource:///modules/zen/ZenWindowSync.sys.mjs",
  DeferredTask: "resource://gre/modules/DeferredTask.sys.mjs",
 });

@@ -28,6 +30,10 @@ XPCOMUtils.defineLazyPreferenceGetter(
  3
 );

+const SHOULD_LOG_TAB_ENTRIES = Services.prefs.getBoolPref(
+  "zen.session-store.log-tab-entries",
+  false
+);
 const SHOULD_BACKUP_FILE = Services.prefs.getBoolPref("zen.session-store.backup-file", true);
 const FILE_NAME = "zen-sessions.jsonlz4";

@@ -51,6 +57,9 @@ class nsZenSidebarObject {
  }

  set data(data) {
+    if (typeof data !== "object") {
+      throw new Error("Sidebar data must be an object");
+    }
    this.#sidebar = data;
  }
 }
@@ -75,14 +84,14 @@ export class nsZenSessionManager {

  init() {
    this.log("Initializing session manager");
-    let backupFile = null;
+    let backupTo = null;
    if (SHOULD_BACKUP_FILE) {
-      backupFile = PathUtils.join(this.#backupFolderPath, FILE_NAME);
+      backupTo = PathUtils.join(this.#backupFolderPath, "recovery.baklz4");
    }
    this.#file = new JSONFile({
      path: this.#storeFilePath,
      compression: "lz4",
-      backupFile,
+      backupTo,
    });
    this.log("Session file path:", this.#file.path);
    this.#deferredBackupTask = new lazy.DeferredTask(async () => {
@@ -93,18 +102,16 @@ export class nsZenSessionManager {
  log(...args) {
    if (lazy.gShouldLog) {
      // eslint-disable-next-line no-console
-      console.log("ZenSessionManager:", ...args);
+      console.debug("ZenSessionManager:", ...args);
    }
  }

  get #storeFilePath() {
-    let profileDir = Services.dirsvc.get("ProfD", Ci.nsIFile).path;
-    return PathUtils.join(profileDir, FILE_NAME);
+    return PathUtils.join(PathUtils.profileDir, FILE_NAME);
  }

  get #backupFolderPath() {
-    let profileDir = Services.dirsvc.get("ProfD", Ci.nsIFile).path;
-    return PathUtils.join(profileDir, "zen-sessions-backup");
+    return PathUtils.join(PathUtils.profileDir, "zen-sessions-backup");
  }

  /**
@@ -218,6 +225,11 @@ export class nsZenSessionManager {
      this._shouldRunMigration = true;
      await this.#getDataFromDBForMigration();
    }
+    if (SHOULD_LOG_TAB_ENTRIES) {
+      for (const tab of this.#sidebar.tabs || []) {
+        this.log("Tab entry in session file:", tab);
+      }
+    }
  }

  get #shouldRestoreOnlyPinned() {
@@ -227,6 +239,13 @@ export class nsZenSessionManager {
    );
  }

+  get #shouldRestoreFromCrash() {
+    return (
+      lazy.SessionStartup.previousSessionCrashed &&
+      Services.prefs.getBoolPref("browser.sessionstore.resume_from_crash")
+    );
+  }
+
  /**
   * Called when the session file is read. Restores the sidebar data
   * into all windows.
@@ -252,23 +271,50 @@ export class nsZenSessionManager {
      }
      return initialState;
    }
+    const allowRestoreUnsynced = Services.prefs.getBoolPref(
+      "zen.session-store.restore-unsynced-windows",
+      true
+    );
+    if (initialState?.windows?.length && !allowRestoreUnsynced) {
+      initialState.windows = initialState.windows.filter((win) => {
+        if (win.isZenUnsynced) {
+          this.log("Skipping unsynced window during restore");
+        }
+        return !win.isZenUnsynced;
+      });
+    }
    // If there are no windows, we create an empty one. By default,
    // firefox would create simply a new empty window, but we want
    // to make sure that the sidebar object is properly initialized.
    // This would happen on first run after having a single private window
    // open when quitting the app, for example.
-    if (!initialState?.windows?.length) {
+    let normalWindowsExist = initialState?.windows?.some(
+      (win) => !win.isPrivate && !win.isPopup && !win.isTaskbarTab && !win.isZenUnsynced
+    );
+    if (!initialState?.windows?.length || !normalWindowsExist) {
      this.log("No windows found in initial state, creating an empty one");
      initialState ||= {};
-      initialState.windows = [
-        {
-          tabs: [],
-        },
-      ];
+      initialState.windows ||= [];
+      initialState.windows.push({
+        tabs: [],
+      });
    }
+    return initialState;
+  }
+
+  /**
+   * Called after @onFileRead, when session startup has crash checkpoint information available.
+   * Restores the sidebar data into all windows, and runs any crash checkpoint related logic,
+   * such as restoring only pinned tabs if the previous session was not crashed and the user
+   * preference is set to do so.
+   *
+   * @param {object} initialState
+   *        The initial session state read from the session file, possibly modified by onFileRead.
+   */
+  onCrashCheckpoints(initialState) {
    // When we don't have browser.startup.page set to resume session,
    // we only want to restore the pinned tabs into the new windows.
-    if (this.#shouldRestoreOnlyPinned && this.#sidebar?.tabs) {
+    if (this.#shouldRestoreOnlyPinned && !this.#shouldRestoreFromCrash && this.#sidebar?.tabs) {
      this.log("Restoring only pinned tabs into windows");
      const sidebar = this.#sidebar;
      sidebar.tabs = (sidebar.tabs || []).filter((tab) => tab.pinned);
@@ -277,30 +323,20 @@ export class nsZenSessionManager {
    // Restore all windows with the same sidebar object, this will
    // guarantee that all tabs, groups, folders and split view data
    // are properly synced across all windows.
-    const allowRestoreUnsynced = Services.prefs.getBoolPref(
-      "zen.session-store.restore-unsynced-windows",
-      true
-    );
    if (!this._shouldRunMigration) {
      this.log(`Restoring Zen session data into ${initialState.windows?.length || 0} windows`);
      for (let i = 0; i < initialState.windows.length; i++) {
        let winData = initialState.windows[i];
-        if (winData.isZenUnsynced) {
-          if (!allowRestoreUnsynced) {
-            // We don't wan't to restore any unsynced windows with the sidebar data.
-            this.log("Skipping restore of unsynced window");
-            delete initialState.windows[i];
-          }
+        if (winData.isZenUnsynced || winData.isPrivate || winData.isPopup || winData.isTaskbarTab) {
          continue;
        }
        this.#restoreWindowData(winData);
      }
    } else if (initialState) {
      this.log("Saving windata state after migration");
-      this.saveState(Cu.cloneInto(initialState, {}));
+      this.saveState(Cu.cloneInto(initialState, {}), true);
    }
    delete this._shouldRunMigration;
-    return initialState;
  }

  get #sidebar() {
@@ -383,6 +419,25 @@ export class nsZenSessionManager {
    return initialState;
  }

+  onRestoringClosedWindow(aWinData) {
+    // We only want to save all pinned tabs if the user preference allows it.
+    // See https://github.com/zen-browser/desktop/issues/12307
+    if (this.#shouldRestoreOnlyPinned && aWinData?.tabs?.length) {
+      this.log("Restoring only pinned tabs for closed window");
+      this.#filterUnpinnedTabs(aWinData);
+    }
+  }
+
+  /**
+   * Filters out all unpinned tabs and groups from the given window data object.
+   *
+   * @param {object} aWindow - The window data object to filter.
+   */
+  #filterUnpinnedTabs(aWindow) {
+    aWindow.tabs = aWindow.tabs.filter((tab) => tab.pinned);
+    aWindow.groups = aWindow.groups?.filter((group) => group.pinned);
+  }
+
  /**
   * Determines if a given window data object is saveable.
   *
@@ -397,8 +452,11 @@ export class nsZenSessionManager {
   * Saves the current session state. Collects data and writes to disk.
   *
   * @param {object} state The current session state.
+   * @param {boolean} soon Whether to save the file soon or immediately.
+   *        If true, the file will be saved asynchronously or when quitting
+   *        the app. If false, the file will be saved immediately.
   */
-  saveState(state) {
+  saveState(state, soon = false) {
    let windows = state?.windows || [];
    windows = windows.filter((win) => this.#isWindowSaveable(win));
    if (!windows.length) {
@@ -407,12 +465,16 @@ export class nsZenSessionManager {
      return;
    }
    this.#collectWindowData(windows);
-    // This would save the data to disk asynchronously or when
-    // quitting the app.
-    this.#file.data = this.#sidebar;
-    this.#file.saveSoon();
+    // This would save the data to disk asynchronously or when quitting the app.
+    let sidebar = this.#sidebar;
+    this.#file.data = sidebar;
+    if (soon) {
+      this.#file.saveSoon();
+    } else {
+      this.#file._save();
+    }
    this.#debounceRegeneration();
-    this.log(`Saving Zen session data with ${this.#sidebar.tabs?.length || 0} tabs`);
+    this.log(`Saving Zen session data with ${sidebar.tabs?.length || 0} tabs`);
  }

  /**
@@ -464,12 +526,12 @@ export class nsZenSessionManager {
      // Now we need to check if we have exceeded the maximum
      // number of backups allowed, and delete the oldest ones
      // if needed.
+      let prefix = PathUtils.join(backupFolder, "zen-sessions-");
      let files = await IOUtils.getChildren(backupFolder);
-      files = files.filter((file) => file.startsWith("zen-sessions-")).sort();
+      files = files.filter((file) => file.startsWith(prefix)).sort();
      for (let i = 0; i < files.length - lazy.gMaxSessionBackups; i++) {
-        const fileToDelete = PathUtils.join(backupFolder, files[i].name);
-        this.log(`Deleting old backup file ${files[i].name}`);
-        await IOUtils.remove(fileToDelete);
+        this.log(`Deleting old backup file ${files[i]}`);
+        await IOUtils.remove(files[i]);
      }
    } catch (e) {
      console.error("ZenSessionManager: Failed to create session file backups", e);
@@ -491,7 +553,7 @@ export class nsZenSessionManager {
      return;
    }
    this.log("Saving closed window session data into Zen session store");
-    this.saveState({ windows: [aWinData] });
+    this.saveState({ windows: [aWinData] }, true);
  }

  /**
@@ -513,6 +575,13 @@ export class nsZenSessionManager {
    this.#sidebar = sidebarData;
  }

+  /**
+   * Filters out tabs that are not useful to restore, such as empty tabs with no group association.
+   * If removeUnpinnedTabs is true, it also filters out unpinned tabs.
+   *
+   * @param {Array} tabs - The array of tab data objects to filter.
+   * @returns {Array} The filtered array of tab data objects.
+   */
  #filterUnusedTabs(tabs) {
    return tabs.filter((tab) => {
      // We need to ignore empty tabs with no group association
@@ -562,10 +631,34 @@ export class nsZenSessionManager {
    if (!sidebar) {
      return;
    }
-    aWindowData.tabs = sidebar.tabs || [];
-    aWindowData.splitViewData = sidebar.splitViewData;
+    // If we should only sync the pinned tabs, we should only edit the unpinned
+    // tabs in the window data and keep the pinned tabs from the window data,
+    // as they should be the same as the ones in the sidebar.
+    if (lazy.gSyncOnlyPinnedTabs) {
+      let pinnedTabs = (sidebar.tabs || []).filter((tab) => tab.pinned);
+      let unpinedWindowTabs = [];
+      if (!this.#shouldRestoreOnlyPinned) {
+        unpinedWindowTabs = (aWindowData.tabs || []).filter((tab) => !tab.pinned);
+      }
+      aWindowData.tabs = [...pinnedTabs, ...unpinedWindowTabs];
+
+      // We restore ALL the split view data in the sidebar, if the group doesn't exist in the window,
+      // it should be a no-op anyways.
+      aWindowData.splitViewData = [
+        ...(sidebar.splitViewData || []),
+        ...(aWindowData.splitViewData || []),
+      ];
+      // Same thing with groups, we restore all the groups from the sidebar, if they don't have any
+      // existing tabs in the window, they should be a no-op.
+      aWindowData.groups = [...(sidebar.groups || []), ...(aWindowData.groups || [])];
+    } else {
+      aWindowData.tabs = sidebar.tabs || [];
+      aWindowData.splitViewData = sidebar.splitViewData;
+      aWindowData.groups = sidebar.groups;
+    }
+
+    // Folders are always pinned, so we dont need to check for the pinned state here.
    aWindowData.folders = sidebar.folders;
-    aWindowData.groups = sidebar.groups;
    aWindowData.spaces = sidebar.spaces;
  }

@@ -591,17 +684,19 @@ export class nsZenSessionManager {
    );
    let windowToClone = windows[0] || {};
    let newWindow = Cu.cloneInto(windowToClone, {});
+    let shouldRestoreOnlyPinned = !lazy.gWindowSyncEnabled || lazy.gSyncOnlyPinnedTabs;
    if (windows.length < 2) {
      // We only want to restore the sidebar object if we found
      // only one normal window to clone from (which is the one
      // we are opening).
      this.log("Restoring sidebar data into new window");
      this.#restoreWindowData(newWindow);
+      shouldRestoreOnlyPinned ||= this.#shouldRestoreOnlyPinned;
    }
    newWindow.tabs = this.#filterUnusedTabs(newWindow.tabs || []);
-    if (!lazy.gWindowSyncEnabled) {
-      // Don't bring over any unpinned tabs if window sync is disabled.
-      newWindow.tabs = newWindow.tabs.filter((tab) => tab.pinned);
+    if (shouldRestoreOnlyPinned) {
+      // Don't bring over any unpinned tabs if window sync is disabled or if syncing only pinned tabs.
+      this.#filterUnpinnedTabs(newWindow);
    }

    // These are window-specific from the previous window state that
--- a/src/zen/sessionstore/ZenWindowSync.sys.mjs
+++ b/src/zen/sessionstore/ZenWindowSync.sys.mjs
@@ -19,10 +19,16 @@ ChromeUtils.defineESModuleGetters(lazy, {
 });

 XPCOMUtils.defineLazyPreferenceGetter(lazy, "gWindowSyncEnabled", "zen.window-sync.enabled", true);
+XPCOMUtils.defineLazyPreferenceGetter(
+  lazy,
+  "gSyncOnlyPinnedTabs",
+  "zen.window-sync.sync-only-pinned-tabs",
+  true
+);
 XPCOMUtils.defineLazyPreferenceGetter(lazy, "gShouldLog", "zen.window-sync.log", true);

 const OBSERVING = ["browser-window-before-show", "sessionstore-windows-restored"];
-const INSTANT_EVENTS = ["SSWindowClosing"];
+const INSTANT_EVENTS = ["SSWindowClosing", "TabSelect", "focus"];
 const UNSYNCED_WINDOW_EVENTS = ["TabOpen"];
 const EVENTS = [
  "TabClose",
@@ -44,9 +50,6 @@ const EVENTS = [
  "ZenTabRemovedFromSplit",
  "ZenSplitViewTabsSplit",

-  "TabSelect",
-
-  "focus",
  ...INSTANT_EVENTS,
  ...UNSYNCED_WINDOW_EVENTS,
 ];
@@ -75,6 +78,13 @@ class nsZenWindowSync {
    lastHandlerPromise: Promise.resolve(),
  };

+  /**
+   * Promise that resolves when the current docshell swap operation is finished.
+   * Used to avoid multiple simultaneous swap operations that could interfere with each other.
+   * For example, when focusing a window AND selecting a tab at the same time.
+   */
+  #docShellSwitchPromise = Promise.resolve();
+
  /**
   * Map of sync handlers for different event types.
   * Each handler is a function that takes the event as an argument.
@@ -163,7 +173,7 @@ class nsZenWindowSync {
  log(...args) {
    if (lazy.gShouldLog) {
      // eslint-disable-next-line no-console
-      console.info("ZenWindowSync:", ...args);
+      console.debug("ZenWindowSync:", ...args);
    }
  }

@@ -241,7 +251,7 @@ class nsZenWindowSync {
        if (tab.pinned && !tab._zenPinnedInitialState) {
          await this.setPinnedTabState(tab);
        }
-        if (!lazy.gWindowSyncEnabled) {
+        if (!lazy.gWindowSyncEnabled || (lazy.gSyncOnlyPinnedTabs && !tab.pinned)) {
          tab._zenContentsVisible = true;
        }
      }
@@ -321,7 +331,7 @@ class nsZenWindowSync {
      return;
    }
    if (INSTANT_EVENTS.includes(aEvent.type)) {
-      this.#handleNextEvent(aEvent);
+      this.#handleNextEventInternal(aEvent);
      return;
    }
    if (this.#eventHandlingContext.window && this.#eventHandlingContext.window !== window) {
@@ -368,30 +378,31 @@ class nsZenWindowSync {
    this.#syncHandlers.delete(aHandler);
  }

+  #handleNextEventInternal(aEvent) {
+    const handler = `on_${aEvent.type}`;
+    if (typeof this[handler] !== "function") {
+      throw new Error(`No handler for event type: ${aEvent.type}`);
+    }
+    return this[handler](aEvent);
+  }
+
  /**
   * Handles the next event by calling the appropriate handler method.
   *
   * @param {Event} aEvent - The event to handle.
   */
-  #handleNextEvent(aEvent) {
-    const handler = `on_${aEvent.type}`;
+  async #handleNextEvent(aEvent) {
    try {
-      if (typeof this[handler] === "function") {
-        let promise = this[handler](aEvent) || Promise.resolve();
-        promise.then(() => {
-          for (let syncHandler of this.#syncHandlers) {
-            try {
-              syncHandler(aEvent);
-            } catch (e) {
-              console.error(e);
-            }
-          }
-        });
-        return promise;
-      }
-      throw new Error(`No handler for event type: ${aEvent.type}`);
+      await this.#handleNextEventInternal(aEvent);
    } catch (e) {
-      return Promise.reject(e);
+      console.error(e);
+    }
+    for (let syncHandler of this.#syncHandlers) {
+      try {
+        syncHandler(aEvent);
+      } catch (e) {
+        console.error(e);
+      }
    }
  }

@@ -784,39 +795,43 @@ class nsZenWindowSync {
  #styleSwapedBrowsers(aOurTab, aOtherTab, callback = undefined, promiseToWait = null) {
    const ourBrowser = aOurTab.linkedBrowser;
    const otherBrowser = aOtherTab.linkedBrowser;
-    return new Promise((resolve) => {
-      aOurTab.ownerGlobal.requestAnimationFrame(async () => {
-        if (callback) {
-          const browserBlob = await aOtherTab.ownerGlobal.PageThumbs.captureToBlob(
-            aOtherTab.linkedBrowser,
-            {
-              fullScale: true,
-              fullViewport: true,
-            }
-          );
+    // eslint-disable-next-line no-async-promise-executor
+    return new Promise(async (resolve) => {
+      if (callback) {
+        const browserBlob = await aOtherTab.ownerGlobal.PageThumbs.captureToBlob(
+          aOtherTab.linkedBrowser,
+          {
+            fullScale: true,
+            fullViewport: true,
+          }
+        );

-          let mySrc = await new Promise((r, re) => {
-            const reader = new FileReader();
-            reader.readAsDataURL(browserBlob);
-            reader.onloadend = function () {
-              // result includes identifier 'data:image/png;base64,' plus the base64 data
-              r(reader.result);
-            };
-            reader.onerror = function () {
-              re(new Error("Failed to read blob as data URL"));
-            };
-          });
+        let mySrc = await new Promise((r, re) => {
+          const reader = new FileReader();
+          reader.readAsDataURL(browserBlob);
+          reader.onloadend = function () {
+            // result includes identifier 'data:image/png;base64,' plus the base64 data
+            r(reader.result);
+          };
+          reader.onerror = function () {
+            re(new Error("Failed to read blob as data URL"));
+          };
+        });

-          this.#createPseudoImageForBrowser(otherBrowser, mySrc);
+        let promise = this.#createPseudoImageForBrowser(otherBrowser, mySrc);
+        await Promise.all([promiseToWait, promise]);
+        aOurTab.ownerGlobal.requestAnimationFrame(() => {
          otherBrowser.setAttribute("zen-pseudo-hidden", "true");
-          await promiseToWait;
-          callback();
-        }
-
-        this.#maybeRemovePseudoImageForBrowser(ourBrowser);
+          ourBrowser.removeAttribute("zen-pseudo-hidden");
+          this.#maybeRemovePseudoImageForBrowser(ourBrowser);
+        });
+        callback();
+      } else {
        ourBrowser.removeAttribute("zen-pseudo-hidden");
-        resolve();
-      });
+        this.#maybeRemovePseudoImageForBrowser(ourBrowser);
+      }
+
+      resolve();
    });
  }

@@ -828,10 +843,25 @@ class nsZenWindowSync {
   */
  #createPseudoImageForBrowser(aBrowser, aSrc) {
    const doc = aBrowser.ownerDocument;
+    const win = aBrowser.ownerGlobal;
    const img = doc.createElement("img");
    img.className = "zen-pseudo-browser-image";
    img.src = aSrc;
+    let promise = new Promise((resolve) => {
+      if (img.complete) {
+        resolve();
+        return;
+      }
+      let finish = () => {
+        win.requestAnimationFrame(() => {
+          resolve();
+        });
+      };
+      img.onload = finish;
+      img.onerror = finish;
+    });
    aBrowser.after(img);
+    return promise;
  }

  /**
@@ -905,20 +935,16 @@ class nsZenWindowSync {
   *
   * @param {Window} aWindow - The window that triggered the event.
   * @param {object} aPreviousTab - The previously selected tab.
-   * @param {boolean} ignoreSameTab - Indicates if the same tab should be ignored.
   */
-  async #onTabSwitchOrWindowFocus(aWindow, aPreviousTab = null, ignoreSameTab = false) {
-    // On some occasions, such as when closing a window, this
-    // function might be called multiple times for the same tab.
-    if (aWindow.gBrowser.selectedTab === this.#lastSelectedTab && !ignoreSameTab) {
-      return;
-    }
+  async #onTabSwitchOrWindowFocus(aWindow, aPreviousTab = null) {
    let activeBrowsers = aWindow.gBrowser.selectedBrowsers;
    let activeTabs = activeBrowsers.map((browser) => aWindow.gBrowser.getTabForBrowser(browser));
    // Ignore previous tabs that are still "active". These scenarios could happen for example,
    // when selecting on a split view tab that was already active.
    if (aPreviousTab?._zenContentsVisible && !activeTabs.includes(aPreviousTab)) {
-      let tabsToSwap = aPreviousTab.splitView ? aPreviousTab.group.tabs : [aPreviousTab];
+      let tabsToSwap = aPreviousTab.group?.hasAttribute("split-view-group")
+        ? aPreviousTab.group.tabs
+        : [aPreviousTab];
      for (const tab of tabsToSwap) {
        const otherTabToShow = this.#getActiveTabFromOtherWindows(aWindow, tab.id, (t) =>
          t?.splitView ? t.group.tabs.some((st) => st.selected) : t?.selected
@@ -953,6 +979,9 @@ class nsZenWindowSync {
   */
  #delegateGenericSyncEvent(aEvent, flags = 0) {
    const item = aEvent.target;
+    if (lazy.gSyncOnlyPinnedTabs && !item.pinned) {
+      return;
+    }
    this.#syncItemForAllWindows(item, flags);
  }

@@ -1089,16 +1118,19 @@ class nsZenWindowSync {

  /* Mark: Event Handlers */

-  on_TabOpen(aEvent) {
+  on_TabOpen(aEvent, { duringPinning = false } = {}) {
    const tab = aEvent.target;
    const window = tab.ownerGlobal;
    const isUnsyncedWindow = window.gZenWorkspaces.privateWindowOrDisabled;
-    if (tab.id) {
+    if (tab.id && !duringPinning) {
      // This tab was opened as part of a sync operation.
      return;
    }
    tab._zenContentsVisible = true;
    tab.id = this.#newTabSyncId;
+    if (lazy.gSyncOnlyPinnedTabs && !tab.pinned) {
+      return;
+    }
    if (isUnsyncedWindow || !lazy.gWindowSyncEnabled) {
      return;
    }
@@ -1116,6 +1148,9 @@ class nsZenWindowSync {
        SYNC_FLAG_ICON | SYNC_FLAG_LABEL | SYNC_FLAG_MOVE
      );
    });
+    if (duringPinning && tab?.splitView) {
+      this.on_ZenSplitViewTabsSplit({ target: tab.group });
+    }
    this.#maybeFlushTabState(tab);
  }

@@ -1137,7 +1172,8 @@ class nsZenWindowSync {
  }

  on_TabMove(aEvent) {
-    return this.#delegateGenericSyncEvent(aEvent, SYNC_FLAG_MOVE);
+    this.#delegateGenericSyncEvent(aEvent, SYNC_FLAG_MOVE);
+    return Promise.resolve();
  }

  on_TabPinned(aEvent) {
@@ -1149,7 +1185,14 @@ class nsZenWindowSync {
    if (!tab._zenPinnedInitialState) {
      tabStatePromise = this.setPinnedTabState(tab);
    }
-    return Promise.all([tabStatePromise, this.on_TabMove(aEvent)]);
+    return Promise.all([
+      tabStatePromise,
+      this.on_TabMove(aEvent).then(() => {
+        if (lazy.gSyncOnlyPinnedTabs) {
+          this.on_TabOpen({ target: tab }, { duringPinning: true });
+        }
+      }),
+    ]);
  }

  on_TabUnpinned(aEvent) {
@@ -1160,7 +1203,11 @@ class nsZenWindowSync {
        delete targetTab._zenPinnedInitialState;
      }
    });
-    return this.on_TabMove(aEvent);
+    return this.on_TabMove(aEvent).then(() => {
+      if (lazy.gSyncOnlyPinnedTabs) {
+        this.on_TabClose({ target: tab });
+      }
+    });
  }

  on_TabAddedToEssentials(aEvent) {
@@ -1182,11 +1229,12 @@ class nsZenWindowSync {
    });
  }

-  on_focus(aEvent) {
+  async on_focus(aEvent) {
    if (typeof aEvent.target !== "object") {
      return;
    }
-    const { ownerGlobal: window } = aEvent.target;
+    await this.#docShellSwitchPromise;
+    const window = Services.focus.activeWindow;
    if (
      !window?.gBrowser ||
      this.#lastFocusedWindow?.deref() === window ||
@@ -1197,17 +1245,21 @@ class nsZenWindowSync {
    }
    this.#lastFocusedWindow = new WeakRef(window);
    this.#lastSelectedTab = new WeakRef(window.gBrowser.selectedTab);
-    return this.#onTabSwitchOrWindowFocus(window);
+    return (this.#docShellSwitchPromise = this.#onTabSwitchOrWindowFocus(window));
  }

-  on_TabSelect(aEvent) {
+  async on_TabSelect(aEvent) {
+    await this.#docShellSwitchPromise;
    const tab = aEvent.target;
    if (this.#lastSelectedTab?.deref() === tab) {
      return;
    }
    this.#lastSelectedTab = new WeakRef(tab);
    const previousTab = aEvent.detail.previousTab;
-    return this.#onTabSwitchOrWindowFocus(aEvent.target.ownerGlobal, previousTab);
+    return (this.#docShellSwitchPromise = this.#onTabSwitchOrWindowFocus(
+      aEvent.target.ownerGlobal,
+      previousTab
+    ));
  }

  on_SSWindowClosing(aEvent) {
@@ -1227,21 +1279,26 @@ class nsZenWindowSync {
    for (let browser of aBrowsers) {
      const tab = this.#swapedTabsEntriesForWC.get(browser.permanentKey);
      if (tab) {
-        let win = tab.ownerGlobal;
-        this.log(`Finalizing swap for tab ${tab.id} on window close`);
-        lazy.TabStateCache.update(
-          tab.linkedBrowser.permanentKey,
-          lazy.TabStateCache.get(browser.permanentKey)
-        );
-        let tabData = this.#getTabEntriesFromCache(tab);
-        let activePageData = tabData.entries[tabData.index - 1] || null;
+        try {
+          let win = tab.ownerGlobal;
+          this.log(`Finalizing swap for tab ${tab.id} on window close`);
+          lazy.TabStateCache.update(
+            tab.linkedBrowser.permanentKey,
+            lazy.TabStateCache.get(browser.permanentKey)
+          );
+          let tabData = this.#getTabEntriesFromCache(tab);
+          let activePageData = tabData.entries[tabData.index - 1] || null;

-        // If the page has a title, set it. When doing a swap and we still didn't
-        // flush the tab state, the title might not be correct.
-        if (activePageData) {
-          win.gBrowser.setInitialTabTitle(tab, activePageData.title, {
-            isContentTitle: activePageData.title && activePageData.title != activePageData.url,
-          });
+          // If the page has a title, set it. When doing a swap and we still didn't
+          // flush the tab state, the title might not be correct.
+          if (activePageData && win?.gBrowser) {
+            win.gBrowser.setInitialTabTitle(tab, activePageData.title, {
+              isContentTitle: activePageData.title && activePageData.title != activePageData.url,
+            });
+          }
+        } catch (e) {
+          // We might have already closed the window at this point, so just ignore any error.
+          console.error(e);
        }
      }
    }
@@ -1343,7 +1400,7 @@ class nsZenWindowSync {

    return new Promise((resolve) => {
      lazy.setTimeout(() => {
-        this.#onTabSwitchOrWindowFocus(window, null, /* ignoreSameTab = */ true).finally(resolve);
+        this.#onTabSwitchOrWindowFocus(window, null).finally(resolve);
      }, 0);
    });
  }
@@ -1351,4 +1408,6 @@ class nsZenWindowSync {

 // eslint-disable-next-line mozilla/valid-lazy
 export const gWindowSyncEnabled = lazy.gWindowSyncEnabled;
+// eslint-disable-next-line mozilla/valid-lazy
+export const gSyncOnlyPinnedTabs = lazy.gSyncOnlyPinnedTabs;
 export const ZenWindowSync = new nsZenWindowSync();
--- a/src/zen/split-view/ZenViewSplitter.mjs
+++ b/src/zen/split-view/ZenViewSplitter.mjs
@@ -208,6 +208,10 @@ class nsZenViewSplitter extends nsZenDOMOperatedFeature {
    if (typeof groupIndex === "undefined") {
      groupIndex = this._data.findIndex((group) => group.tabs.includes(tab));
    }
+    // If groupIndex === -1, so `this._data.findIndex` couldn't find the split group
+    if (groupIndex < 0) {
+      return;
+    }
    const group = this._data[groupIndex];
    const tabIndex = group.tabs.indexOf(tab);
    group.tabs.splice(tabIndex, 1);
@@ -259,6 +263,33 @@ class nsZenViewSplitter extends nsZenDOMOperatedFeature {
    return element;
  }

+  _calculateDropSide(event, panelsRect) {
+    const { width, height } = panelsRect;
+    const { clientX, clientY } = event;
+    // TODO(octaviusz): Maybe we should add this as preference
+    // `zen.splitView.tab-drop-treshold`
+    const quarterWidth = width / 4;
+    const quarterHeight = height / 4;
+
+    const edges = [
+      { side: "left", dist: clientX - panelsRect.left, threshold: quarterWidth },
+      { side: "right", dist: panelsRect.right - clientX, threshold: quarterWidth },
+      { side: "top", dist: clientY - panelsRect.top, threshold: quarterHeight },
+      { side: "bottom", dist: panelsRect.bottom - clientY, threshold: quarterHeight },
+    ];
+
+    let closestEdge = null;
+    let minDist = Infinity;
+    for (const edge of edges) {
+      if (edge.dist < edge.threshold && edge.dist < minDist) {
+        minDist = edge.dist;
+        closestEdge = edge;
+      }
+    }
+
+    return closestEdge ? closestEdge.side : null;
+  }
+
  // eslint-disable-next-line complexity
  onBrowserDragOverToSplit(event) {
    gBrowser.tabContainer.tabDragAndDrop.clearSpaceSwitchTimer();
@@ -303,6 +334,7 @@ class nsZenViewSplitter extends nsZenDOMOperatedFeature {
    }
    const panelsRect = gBrowser.tabbox.getBoundingClientRect();
    const panelsWidth = panelsRect.width;
+    const panelsHeight = panelsRect.height;
    if (
      event.clientX > panelsRect.left + panelsWidth - 10 ||
      event.clientX < panelsRect.left + 10 ||
@@ -311,11 +343,17 @@ class nsZenViewSplitter extends nsZenDOMOperatedFeature {
    ) {
      return;
    }
+    const dropSide = this._calculateDropSide(event, panelsRect);
+    if (!dropSide) {
+      return;
+    }
    // first quarter or last quarter of the screen, but not the middle
    if (
      !(
        event.clientX < panelsRect.left + panelsWidth / 4 ||
-        event.clientX > panelsRect.left + (panelsWidth / 4) * 3
+        event.clientX > panelsRect.left + (panelsWidth / 4) * 3 ||
+        event.clientY < panelsRect.top + panelsHeight / 4 ||
+        event.clientY > panelsRect.top + (panelsHeight / 4) * 3
      )
    ) {
      return;
@@ -336,93 +374,113 @@ class nsZenViewSplitter extends nsZenDOMOperatedFeature {
    this._canDrop = true;
    // eslint-disable-next-line mozilla/valid-services
    Services.zen.playHapticFeedback();
-    {
-      this._draggingTab = draggedTab;
-      gBrowser.selectedTab = oldTab;
-      this._hasAnimated = true;
-      this.tabBrowserPanel.setAttribute("dragging-split", "true");
-      // Add a min width to all the browser elements to prevent them from resizing
-      // eslint-disable-next-line no-shadow
-      const panelsWidth = gBrowser.tabbox.getBoundingClientRect().width;
-      let numOfTabsToDivide = 2;
-      if (currentView) {
-        numOfTabsToDivide = currentView.tabs.length + 1;
+    this._draggingTab = draggedTab;
+    gBrowser.selectedTab = oldTab;
+    this._hasAnimated = true;
+    this.tabBrowserPanel.setAttribute("dragging-split", "true");
+    this._animateDropEdge(dropSide, currentView, draggedTab, oldTab);
+  }
+
+  _animateDropEdge(dropSide, currentView, draggedTab, oldTab) {
+    // Add a min width to all the browser elements to prevent them from resizing
+    // eslint-disable-next-line no-shadow
+    const { height, width } = gBrowser.tabbox.getBoundingClientRect();
+    let numOfTabsToDivide = 2;
+    if (currentView) {
+      numOfTabsToDivide = currentView.tabs.length + 1;
+    }
+    const halfWidth = width / numOfTabsToDivide;
+    const halfHeight = height / numOfTabsToDivide;
+    const side = dropSide;
+    for (const browser of gBrowser.browsers) {
+      if (!browser) {
+        continue;
      }
-      const halfWidth = panelsWidth / numOfTabsToDivide;
-      let threshold =
-        gNavToolbox.getBoundingClientRect().width *
-        (gZenVerticalTabsManager._prefsRightSide ? 0 : 1);
-      if (gZenCompactModeManager.preference) {
-        threshold = 0;
+      const { width: browserWidth, height: browserHeight } = browser.getBoundingClientRect();
+      // Only apply it to the left side because if we add it to the right side,
+      // we wont be able to move the element to the left.
+      // FIXME: This is a workaround, we should find a better way to do this
+      switch (side) {
+        case "left":
+          browser.style.minWidth = `${browserWidth}px`;
+          break;
+        case "top":
+          browser.style.minHeight = `${browserHeight}px`;
+          break;
      }
-      const side = event.clientX - threshold > halfWidth ? "right" : "left";
-      for (const browser of gBrowser.browsers) {
-        if (!browser) {
-          continue;
+    }
+    this.fakeBrowser = document.createXULElement("vbox");
+    window.addEventListener("dragend", this.onBrowserDragEndToSplit, { once: true });
+    const padding = ZenThemeModifier.elementSeparation;
+    this.fakeBrowser.setAttribute("flex", "1");
+    this.fakeBrowser.id = "zen-split-view-fake-browser";
+    if (oldTab.splitView) {
+      this.fakeBrowser.setAttribute("has-split-view", "true");
+    }
+    gBrowser.tabbox.appendChild(this.fakeBrowser);
+    this.fakeBrowser.setAttribute("side", side);
+    let animateTabBox = null;
+    let animateFakeBrowser = null;
+    switch (side) {
+      case "left":
+        animateTabBox = {
+          padding: [0, `0 0 0 ${halfWidth}px`],
+        };
+        animateFakeBrowser = {
+          width: [0, `${halfWidth - padding}px`],
+          margin: [0, `0 0 0 ${-halfWidth}px`],
+        };
+        break;
+      case "right":
+        animateTabBox = {
+          padding: [0, `0 ${halfWidth}px 0 0`],
+        };
+        animateFakeBrowser = {
+          width: [0, `${halfWidth - padding}px`],
+        };
+        break;
+
+      case "top":
+        animateTabBox = {
+          padding: [0, `${halfHeight}px 0 0 0`],
+        };
+        animateFakeBrowser = {
+          height: [0, `${halfHeight - padding}px`],
+          margin: [0, `${-halfHeight}px 0 0 0`],
+        };
+        break;
+
+      case "bottom":
+        animateTabBox = {
+          padding: [0, `0 0 ${halfHeight}px 0`],
+        };
+        animateFakeBrowser = {
+          height: [0, `${halfHeight - padding}px`],
+        };
+        break;
+    }
+
+    this._finishAllAnimatingPromise = Promise.all([
+      gZenUIManager.motion.animate(gBrowser.tabbox, animateTabBox, {
+        duration: 0.1,
+        easing: "ease-out",
+      }),
+      gZenUIManager.motion.animate(this.fakeBrowser, animateFakeBrowser, {
+        duration: 0.1,
+        easing: "ease-out",
+      }),
+    ]);
+    if (this._finishAllAnimatingPromise) {
+      this._finishAllAnimatingPromise.then(() => {
+        if (draggedTab !== oldTab) {
+          draggedTab.linkedBrowser.docShellIsActive = false;
+          draggedTab.linkedBrowser
+            .closest(".browserSidebarContainer")
+            .classList.remove("deck-selected");
        }
-        const width = browser.getBoundingClientRect().width;
-        // Only apply it to the left side because if we add it to the right side,
-        // we wont be able to move the element to the left.
-        // FIXME: This is a workaround, we should find a better way to do this
-        if (side === "left") {
-          browser.style.minWidth = `${width}px`;
-        }
-      }
-      this.fakeBrowser = document.createXULElement("vbox");
-      window.addEventListener("dragend", this.onBrowserDragEndToSplit, { once: true });
-      const padding = ZenThemeModifier.elementSeparation;
-      this.fakeBrowser.setAttribute("flex", "1");
-      this.fakeBrowser.id = "zen-split-view-fake-browser";
-      if (oldTab.splitView) {
-        this.fakeBrowser.setAttribute("has-split-view", "true");
-      }
-      gBrowser.tabbox.appendChild(this.fakeBrowser);
-      this.fakeBrowser.setAttribute("side", side);
-      this._finishAllAnimatingPromise = Promise.all([
-        gZenUIManager.motion.animate(
-          gBrowser.tabbox,
-          side === "left"
-            ? {
-                paddingLeft: [0, `${halfWidth}px`],
-                paddingRight: 0,
-              }
-            : {
-                paddingRight: [0, `${halfWidth}px`],
-                paddingLeft: 0,
-              },
-          {
-            duration: 0.1,
-            easing: "ease-out",
-          }
-        ),
-        gZenUIManager.motion.animate(
-          this.fakeBrowser,
-          {
-            width: [0, `${halfWidth - padding}px`],
-            ...(side === "left"
-              ? {
-                  marginLeft: [0, `${-halfWidth}px`],
-                }
-              : {}),
-          },
-          {
-            duration: 0.1,
-            easing: "ease-out",
-          }
-        ),
-      ]);
-      if (this._finishAllAnimatingPromise) {
-        this._finishAllAnimatingPromise.then(() => {
-          if (draggedTab !== oldTab) {
-            draggedTab.linkedBrowser.docShellIsActive = false;
-            draggedTab.linkedBrowser
-              .closest(".browserSidebarContainer")
-              .classList.remove("deck-selected");
-          }
-          this.fakeBrowser.addEventListener("dragleave", this.onBrowserDragEndToSplit);
-          this._canDrop = true;
-        });
-      }
+        this.fakeBrowser.addEventListener("dragleave", this.onBrowserDragEndToSplit);
+        this._canDrop = true;
+      });
    }
  }

@@ -447,12 +505,14 @@ class nsZenViewSplitter extends nsZenDOMOperatedFeature {
      return;
    }
    const panelsWidth = panelsRect.width;
+    const panelsHeight = panelsRect.height;
    let numOfTabsToDivide = 2;
    const currentView = this._data[this._lastOpenedTab.splitViewValue];
    if (currentView) {
      numOfTabsToDivide = currentView.tabs.length + 1;
    }
    const halfWidth = panelsWidth / numOfTabsToDivide;
+    const halfHeight = panelsHeight / numOfTabsToDivide;
    const padding = ZenThemeModifier.elementSeparation;
    if (!this.fakeBrowser) {
      return;
@@ -464,39 +524,60 @@ class nsZenViewSplitter extends nsZenDOMOperatedFeature {
      ...gBrowser.tabContainer.tabDragAndDrop.originalDragImageArgs
    );
    this._canDrop = false;
-    Promise.all([
-      gZenUIManager.motion.animate(
-        gBrowser.tabbox,
-        side === "left"
-          ? {
-              paddingLeft: [`${halfWidth}px`, 0],
-            }
-          : {
-              paddingRight: [`${halfWidth}px`, 0],
-            },
-        {
-          duration: 0.1,
-          easing: "ease-out",
-        }
-      ),
-      gZenUIManager.motion.animate(
-        this.fakeBrowser,
-        {
-          width: [`${halfWidth - padding * 2}px`, 0],
-          ...(side === "left"
-            ? {
-                marginLeft: [`${-halfWidth}px`, 0],
-              }
-            : {}),
-        },
-        {
-          duration: 0.1,
-          easing: "ease-out",
-        }
-      ),
-    ]).finally(() => {
-      this._maybeRemoveFakeBrowser();
-    });
+    let animateTabBox = null;
+    let animateFakeBrowser = null;
+    switch (side) {
+      case "left":
+        animateTabBox = {
+          padding: [`0 0 0 ${halfWidth}px`, 0],
+        };
+        animateFakeBrowser = {
+          width: [`${halfWidth - padding}px`, 0],
+          margin: [`0 0 0 ${-halfWidth}px`, 0],
+        };
+        break;
+      case "right":
+        animateTabBox = {
+          padding: [`0 ${halfWidth}px 0 0`, 0],
+        };
+        animateFakeBrowser = {
+          width: [`${halfWidth - padding}px`, 0],
+        };
+        break;
+      case "top":
+        animateTabBox = {
+          padding: [`${halfHeight}px 0 0 0`, 0],
+        };
+        animateFakeBrowser = {
+          height: [`${halfHeight - padding}px`, 0],
+          margin: [`${-halfHeight}px 0 0 0`, 0],
+        };
+        break;
+      case "bottom":
+        animateTabBox = {
+          padding: [`0 0 ${halfHeight}px 0`, 0],
+        };
+        animateFakeBrowser = {
+          height: [`${halfHeight - padding}px`, 0],
+        };
+        break;
+    }
+
+    this._finishAllAnimatingPromise = Promise.all([
+      gZenUIManager.motion.animate(gBrowser.tabbox, animateTabBox, {
+        duration: 0.1,
+        easing: "ease-out",
+      }),
+      gZenUIManager.motion.animate(this.fakeBrowser, animateFakeBrowser, {
+        duration: 0.1,
+        easing: "ease-out",
+      }),
+    ]);
+    if (this._finishAllAnimatingPromise) {
+      this._finishAllAnimatingPromise.then(() => {
+        this._maybeRemoveFakeBrowser();
+      });
+    }
  }

  /**
@@ -1845,12 +1926,24 @@ class nsZenViewSplitter extends nsZenDOMOperatedFeature {
    const dropSide = this.fakeBrowser?.getAttribute("side");
    const containerRect = this.fakeBrowser.getBoundingClientRect();
    const padding = ZenThemeModifier.elementSeparation;
-    const dropTarget = document.elementFromPoint(
-      dropSide === "left"
-        ? containerRect.left + containerRect.width + padding + 5
-        : containerRect.left - padding - 5,
-      event.clientY
-    );
+    let targetX = event.clientX;
+    let targetY = event.clientY;
+    switch (dropSide) {
+      case "left":
+        targetX = containerRect.left + containerRect.width + padding + 5;
+        break;
+      case "right":
+        targetX = containerRect.left - padding - 5;
+        break;
+      case "top":
+        targetY = containerRect.top + containerRect.height + padding + 5;
+        break;
+      case "bottom":
+        targetY = containerRect.top - padding - 5;
+        break;
+    }
+
+    const dropTarget = document.elementFromPoint(targetX, targetY);
    const browser =
      dropTarget?.closest("browser") ??
      dropTarget?.closest(".browserSidebarContainer")?.querySelector("browser");
@@ -1862,7 +1955,7 @@ class nsZenViewSplitter extends nsZenDOMOperatedFeature {

    let droppedOnTab = gZenGlanceManager.getTabOrGlanceParent(gBrowser.getTabForBrowser(browser));
    if (droppedOnTab === this._draggingTab) {
-      this.createEmptySplit(dropSide == "right");
+      this.createEmptySplit(dropSide);
      return true;
    }

@@ -1919,29 +2012,21 @@ class nsZenViewSplitter extends nsZenDOMOperatedFeature {
              }
            }
          }
-
-          const droppedOnSplitNode = this.getSplitNodeFromTab(droppedOnTab);
-          const parentNode = droppedOnSplitNode.parent;
-
          // Then add the tab to the split view
          group.tabs.push(draggedTab);

-          // If dropping on a side, create a new split in that direction
+          // If dropping on a side, wrap entire layout in a new split at the root level
          if (hoverSide !== "center") {
            const splitDirection = hoverSide === "left" || hoverSide === "right" ? "row" : "column";
-            if (parentNode.direction !== splitDirection) {
-              this.splitIntoNode(
-                droppedOnSplitNode,
-                new nsSplitLeafNode(draggedTab, 50),
-                hoverSide,
-                0.5
-              );
+            const rootNode = group.layoutTree;
+            const prepend = hoverSide === "left" || hoverSide === "top";
+
+            if (rootNode.direction === splitDirection) {
+              // Root has the same direction, add as a new child of the root
+              this.addTabToSplit(draggedTab, rootNode, prepend);
            } else {
-              this.addTabToSplit(
-                draggedTab,
-                parentNode,
-                /* prepend = */ hoverSide === "left" || hoverSide === "top"
-              );
+              // Different direction, wrap root in a new split node
+              this.splitIntoNode(rootNode, new nsSplitLeafNode(draggedTab, 50), hoverSide, 0.5);
            }
          } else {
            this.addTabToSplit(draggedTab, group.layoutTree);
@@ -1951,13 +2036,14 @@ class nsZenViewSplitter extends nsZenDOMOperatedFeature {
        }
      } else {
        // Create new split view with layout based on drop position
-        let gridType = "vsep";
+        const gridType = dropSide === "top" || dropSide === "bottom" ? "hsep" : "vsep";
+        const topOrLeft = dropSide === "top" || dropSide === "left";

        // Put tabs always as if it was dropped from the left
        this.splitTabs(
-          dropSide == "left" ? [draggedTab, droppedOnTab] : [droppedOnTab, draggedTab],
+          topOrLeft ? [draggedTab, droppedOnTab] : [droppedOnTab, draggedTab],
          gridType,
-          dropSide == "left" ? 0 : 1
+          topOrLeft ? 0 : 1
        );
      }

@@ -2192,14 +2278,16 @@ class nsZenViewSplitter extends nsZenDOMOperatedFeature {
    }
  }

-  createEmptySplit(rightSide = true) {
+  createEmptySplit(side = "right") {
    const selectedTab = gBrowser.selectedTab;
    const emptyTab = gZenWorkspaces._emptyTab;
-    let tabs = rightSide ? [selectedTab, emptyTab] : [emptyTab, selectedTab];
+    const gridType = side === "top" || side === "bottom" ? "hsep" : "vsep";
+    const topOrLeft = side === "top" || side === "left";
+    let tabs = topOrLeft ? [emptyTab, selectedTab] : [selectedTab, emptyTab];
    const data = {
      tabs,
-      gridType: "grid",
-      layoutTree: this.calculateLayoutTree(tabs, "grid"),
+      gridType,
+      layoutTree: this.calculateLayoutTree(tabs, gridType),
    };
    this.#withoutSplitViewTransition(() => {
      this._data.push(data);
@@ -2234,9 +2322,9 @@ class nsZenViewSplitter extends nsZenDOMOperatedFeature {
              gBrowser.selectedTab = selectedTab;
              this.resetTabState(emptyTab, false);
              this.splitTabs(
-                rightSide ? [selectedTab, newSelectedTab] : [newSelectedTab, selectedTab],
-                "grid",
-                rightSide ? 1 : 0
+                topOrLeft ? [newSelectedTab, selectedTab] : [selectedTab, newSelectedTab],
+                gridType,
+                topOrLeft ? 0 : 1
              );
            } else {
              cleanup();
--- a/src/zen/split-view/zen-decks.css
+++ b/src/zen/split-view/zen-decks.css
@@ -44,12 +44,12 @@
 #zen-splitview-dropzone {
  position: absolute !important;

-  margin: var(--zen-split-column-gap) var(--zen-split-row-gap) !important;
-  margin-bottom: 0 !important;
-  margin-left: 0 !important;
+  margin: var(--zen-split-column-gap) var(--zen-split-row-gap);
+  margin-bottom: 0;
+  margin-left: 0;

  &.browserSidebarContainer:not([zen-split='true']) {
-    margin-top: 0 !important;
+    margin-top: 0;
    visibility: hidden;
  }
 }
@@ -204,6 +204,15 @@
  overflow: hidden;
  will-change: width, margin-left;

+  &[side='top'],
+  &[side='bottom'] {
+    width: 100%;
+    
+    &[has-split-view='true'] {
+      width: calc(100% - var(--zen-element-separation));
+    }
+  }
+
  &[side='right'] {
    right: 0;

@@ -211,6 +220,10 @@
      right: var(--zen-element-separation);
    }
  }
+
+  &[side='bottom'] {
+    bottom: 0;
+  }
 }

 #zen-split-view-drag-image {
--- a/src/zen/tabs/ZenPinnedTabManager.mjs
+++ b/src/zen/tabs/ZenPinnedTabManager.mjs
@@ -531,8 +531,16 @@ class nsZenPinnedTabManager extends nsZenDOMOperatedFeature {
    const isVisible = contextTab.pinned && !contextTab.multiselected;
    const isEssential = contextTab.getAttribute("zen-essential");
    const zenAddEssential = document.getElementById("context_zen-add-essential");
-    document.getElementById("context_zen-reset-pinned-tab").hidden = !isVisible;
-    document.getElementById("context_zen-replace-pinned-url-with-current").hidden = !isVisible;
+    const zenResetPinnedTab = document.getElementById("context_zen-reset-pinned-tab");
+    const zenReplacePinnedUrl = document.getElementById(
+      "context_zen-replace-pinned-url-with-current"
+    );
+    [zenResetPinnedTab, zenReplacePinnedUrl].forEach((element) => {
+      if (element) {
+        element.hidden = !isVisible;
+        document.l10n.setArgs(element, { isEssential });
+      }
+    });
    zenAddEssential.hidden = isEssential || !!contextTab.group;
    document.l10n
      .formatValue("tab-context-zen-add-essential-badge", {
@@ -560,9 +568,6 @@ class nsZenPinnedTabManager extends nsZenDOMOperatedFeature {

  // eslint-disable-next-line complexity
  moveToAnotherTabContainerIfNecessary(event, draggedTab, movingTabs, dropIndex) {
-    if (!this.enabled) {
-      return false;
-    }
    let newIndex = dropIndex;
    let fromDifferentWindow = false;
    movingTabs = Array.from(movingTabs || draggedTab)
--- a/src/zen/tabs/zen-tabs/vertical-tabs.css
+++ b/src/zen/tabs/zen-tabs/vertical-tabs.css
@@ -209,7 +209,7 @@
  }

  :root[zen-unsynced-window="true"] & {
-    transform: translateY(-4px);
+    display: none !important;
  }
 }

@@ -297,7 +297,7 @@

  --tab-block-margin: 2px;
  --tab-selected-bgcolor: light-dark(rgba(255, 255, 255, 0.8), rgba(255, 255, 255, 0.18));
-  --tab-selected-shadow: 0 1px 1px 1px light-dark(rgba(0, 0, 0, 0.09), rgba(0, 0, 0, 0.05)) !important;
+  --tab-selected-shadow: 0 1px 1px 0px light-dark(rgba(0, 0, 0, 0.09), rgba(0, 0, 0, 0.05)) !important;
  grid-gap: 0 !important;

  &[overflow]::after,
--- a/src/zen/tests/mochitests/moz.build
+++ b/src/zen/tests/mochitests/moz.build
@@ -6,9 +6,12 @@
 # This file is autogenerated by scripts/import_external_tests.py
 # Do not edit manually.

+
 BROWSER_CHROME_MANIFESTS += [
 	"safebrowsing/browser.toml",
 	"sandbox/browser.toml",
 	"shell/browser.toml",
 	"tooltiptext/browser.toml",
+]
+XPCSHELL_TESTS_MANIFESTS += [
 ]
--- a/Show More
+++ b/Show More
Author	SHA1	Message	Date
mr. m	5a26cb6601	feat: Correctly start backup before-write session files, b=no-bug, c=folders	2026-02-13 00:01:35 +01:00
mr. m	2eb09f092c	fix: Add a flag to change labels when restoring, b=bug #12152 , c=no-component	2026-02-12 20:19:02 +01:00
mr. m	66081e97f6	fix: Remove clip overflow from nav-bar and update rust version, b=no-bug, c=workflows, common	2026-02-12 19:58:58 +01:00
mr. m	08873b0ce7	chore: Bump up rustc version, b=no-bug, c=no-component	2026-02-12 18:41:40 +01:00
mr. m	6dce6d60e9	fix: Fixed window caption buttons not having any padding, b=no-bug, c=common	2026-02-12 17:59:18 +01:00
mr. m	302e321da6	Merge branch 'dev' of https://github.com/zen-browser/desktop into dev	2026-02-12 12:05:49 +01:00
mr. m	5d5d51c6f3	fix: Only apply transparent background to windows of type `navigator:browser`, b=no-bug, c=common	2026-02-12 11:58:42 +01:00
Andrey Vlasenko	262209f5a3	feat: Add search option for URL-like input, p=#11998 Co-authored-by: mr. m <91018726+mr-cheffy@users.noreply.github.com> Co-authored-by: Mr. M <mr.m@tuta.com>	2026-02-11 23:55:53 +01:00
Mr. M	aa4aae9e26	feat: Dont restore content to unsynced windows, b=no-bug, c=no-component	2026-02-11 23:46:59 +01:00
Mr. M	827b89d4e8	feat: Added --blank-window command line argument, b=no-bug, c=common, workspaces	2026-02-11 22:52:32 +01:00
mr. m	a1e7af81cc	feat: Take always into account that no normal window may exist when restoring, b=no-bug, c=no-component	2026-02-11 20:35:56 +01:00
mr. m	1db7e19037	Merge branch 'dev' of https://github.com/zen-browser/desktop into dev	2026-02-11 13:47:50 +01:00
mr. m	c7db15fe9d	feat: New ignore rules to moz.configure for patch calculations, b=no-bug, c=scripts	2026-02-11 13:47:34 +01:00
franky	502d3f7d94	fix: Restore current page URL when urlbar is emptied and blurred, p=#12322, c=no-component When users click the address bar, clear all text, and then click away to blur, the urlbar stays empty instead of restoring the current page URL. This adds a handleRevert() call on blur when the urlbar content is empty (non-newtab mode), so the current page URL is properly restored. Partial input is still preserved on blur as before.	2026-02-11 12:50:30 +01:00
mr. m	bd0651165c	fix: Fixed spaces disappearing when clearing all history, b=closes #12326 , c=no-component	2026-02-11 12:34:44 +01:00
mr. m	af4f336bf5	fix: Make sure to save the state instantly on some occations, b=bug #12152 , c=scripts	2026-02-11 11:59:05 +01:00
mr. m	bffc16ba29	chore: Run module list through a use-moz-source migration, b=no-bug, c=common, glance, workspaces	2026-02-11 00:35:08 +01:00
mr. m	7c53549076	feat: Allow favicons to have white boxes for more result types, b=no-bug, c=common	2026-02-10 13:53:54 +01:00
mr. m	0fe3a4af10	feat: Only allow overflowing webexts for twilight, b=no-bug, c=common, tabs	2026-02-10 13:44:27 +01:00
mr. m	4d1d4ab1b6	feat: Add pref to force synced windows to open on DnD, b=no-bug, c=no-component	2026-02-10 11:50:23 +01:00
mr. m	2990de8366	fix: Fixed wrong capitalized text for MacOS menu bar, b=closes #12213 , c=common	2026-02-09 23:38:13 +01:00
mr. m	76966ee1c3	feat: Make sure to always restore tabs from a crash, b=no-bug, c=no-component	2026-02-09 23:14:51 +01:00
mr. m	4f9a932e77	fix: Fixed unpinned tabs not being cleared when the pref is off, b=closes #12307 , c=no-component	2026-02-09 11:37:10 +01:00
mr. m	f2603521e5	chore: Update external patches, b=no-bug, c=folders	2026-02-09 11:34:02 +01:00
mr. m	24f695c452	Merge branch 'dev' of https://github.com/zen-browser/desktop into dev	2026-02-09 09:02:55 +01:00
mr. m	f5effd4dcd	feat: Add preference to focus on urlbar on startup, b=no-bug, c=workspaces	2026-02-09 09:02:39 +01:00
Mr. M	b5bb7d7c8b	feat: Make sure to use the proper parent reference for XDG paths, b=bug #11917 , c=no-component	2026-02-08 20:07:14 +01:00
mr. m	604365dd38	chore: Update external mochitests, b=no-bug, c=tests, scripts, common	2026-02-08 19:20:36 +01:00
TogiFerretFerret	466d089fc0	feat: Add zen identification info, b=closes #12198 , p=#12295 * feat: add zen identification to extension runtime for zen-specific features * chore: add branding to nightly to assist with certain testing (e.g. browser identification) * test: assert zen info in runtime.getBrowserInfo * Revert "test: assert zen info in runtime.getBrowserInfo" This reverts commit `94cfeff29f` as the tests fail even without this commit. * Discard changes to surfer.json * chore: remove platform from getBrowserInfo (as requested) --------- Co-authored-by: mr. m <91018726+mr-cheffy@users.noreply.github.com>	2026-02-08 17:48:04 +01:00
Roman	e28a10f6a9	fix: Use optional chaining and nullish coalescing in resetButton, p=#12300 Signed-off-by: Roman <58283566+rmdeuce@users.noreply.github.com>	2026-02-08 13:15:57 +01:00
mr. m	102be6cd90	fix: Remove psueod hidden browser background on close, b=no-bug, c=no-component	2026-02-08 13:15:42 +01:00
mr. m	6e1e1d061b	fix: Fixed clicking on the 'add' button not closing the panel, b=no-bug, c=common, workspaces	2026-02-08 11:19:46 +01:00
mr. m	43250d6d37	fix: Fixed bookmarks not being synced with mozilla account, b=bug #12133 , c=workspaces	2026-02-08 10:48:12 +01:00
mr. m	12f0c455d1	fix: Fixed 'restore previous tabs' ignored when only pinned sync is enabled, b=closes #12297 , c=tabs	2026-02-08 10:35:05 +01:00
Andrey Bochkarev	049c3c6f54	feat: Implement vertical dnd tab splitting, p=#12289	2026-02-07 23:59:28 +01:00
Samuel Akhaze	658ac94334	fix: Fixed Incorrect (Reset pinned tab/Replace pinned url) Text on Essential tab context menu, p=#12283	2026-02-07 23:59:15 +01:00
mr. m	09a90099c7	Merge branch 'dev' of https://github.com/zen-browser/desktop into dev	2026-02-07 23:52:51 +01:00
mr. m	051470f139	feat: Small polishing changes, b=no-bug, c=common, workspaces	2026-02-07 21:25:24 +01:00
dependabot[bot]	8f1cb88c11	chore(deps-dev): bump lodash, p=#12292 Bumps the npm_and_yarn group with 1 update in the / directory: [lodash](https://github.com/lodash/lodash). Updates `lodash` from 4.17.21 to 4.17.23 - [Release notes](https://github.com/lodash/lodash/releases) - [Commits](https://github.com/lodash/lodash/compare/4.17.21...4.17.23) --- updated-dependencies: - dependency-name: lodash dependency-version: 4.17.23 dependency-type: indirect dependency-group: npm_and_yarn ... Signed-off-by: dependabot[bot] <support@github.com> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>	2026-02-07 18:49:21 +01:00
mr. m	3ef233a4c2	Merge branch 'dev' of https://github.com/zen-browser/desktop into dev	2026-02-07 18:48:46 +01:00
mr. m	38fcd7e872	fix: Fixed private windows closing when all tabs are cleared, b=closes #12242 , c=common, folders, tabs, workspaces	2026-02-07 18:47:06 +01:00
mr. m	76f17c3a57	chore: Automatically import patches from phabricator and librewolf, p=#12271 * chore: Automatically import patches from phabricator and librewolf, b=no-bug, c=workflows, scripts Signed-off-by: mr. m <91018726+mr-cheffy@users.noreply.github.com> * feat: Remove legacy flag, b=no-bug, c=common, configs ---------	2026-02-07 18:02:40 +01:00
mr. m	b5c2451525	fix: Fixed overflowing addons not opening the panel at the correct anchor, b=no-bug, c=common	2026-02-07 16:51:44 +01:00
mr. m	ba2a854784	feat: Overflow web extensions below the urlbar, p=#12273 * feat: Overflow web extensions below the urlbar, b=no-bug, c=common * chore: Ignore toolbar CSS, b=no-bug, c=no-component	2026-02-06 22:56:11 +01:00
mr. m	c9474cecc0	feat: Remove null-setting for split view data on restore, b=no-bug, c=no-component	2026-02-06 14:10:02 +01:00
mr. m	531be839c9	fix: Fixed frozen window when restore split data is null, b=closes #12260 , c=no-component	2026-02-06 14:04:04 +01:00
mr. m	226486b973	fix: Fixed selecting tabs when pinned tabs are collapsed, b=no-bug, c=no-component	2026-02-06 12:45:24 +01:00
mr. m	5a137c95e5	fix: Fixed wrong highlight possition in compact mode, b=closes #12252 , c=compact-mode	2026-02-05 23:23:17 +01:00
mr. m	e6154ceb99	feat: Make sure we properly restore split views when only pinned sync is enabled, b=no-bug, c=no-component	2026-02-05 23:01:49 +01:00
mr. m	1ea5d2fa6f	feat: Import `zen.window-sync.sync-only-pinned-tabs` to the prefs list, b=no-bug, c=no-component	2026-02-05 11:18:02 +01:00
mr. m	97d5ebc21e	feat: Add pref observer for `zen.window-sync.sync-only-pinned-tabs` setting, b=no-bug, c=no-component	2026-02-05 11:14:48 +01:00
mr. m	442ec2a5d1	chore: Bump version and format, b=no-bug, c=tests	2026-02-05 11:13:02 +01:00
mr. m	43ae672b44	feat: Revert migration step for syncing only pinned tabs, b=no-bug, c=common	2026-02-05 11:12:01 +01:00
mr. m	84a54c9dbb	feat: Add option to only sync up pinned tabs, b=closes #12173 , p=#12246, c=common, tabs	2026-02-05 11:05:37 +01:00
mr. m	6c53c3bf37	chore: Sync upstream Firefox to version `147.0.3`, p=#12243 * chore: Sync upstream to `Firefox 147.0.3` * Update candidate version to 147.0.3 Signed-off-by: mr. m <91018726+mr-cheffy@users.noreply.github.com> * Update Twilight version to RC 147.0.3 in README Signed-off-by: mr. m <91018726+mr-cheffy@users.noreply.github.com> --------- Signed-off-by: mr. m <91018726+mr-cheffy@users.noreply.github.com>	2026-02-05 11:04:53 +01:00
mr. m	66686ab7f8	New Crowdin updates, p=#11954 * New translations zen-general.ftl (Lithuanian) * New translations zen-general.ftl (Portuguese) * New translations zen-preferences.ftl (Lithuanian) * New translations zen-preferences.ftl (Swedish) * New translations zen-preferences.ftl (Chinese Traditional) * New translations zen-preferences.ftl (Welsh) * New translations zen-menubar.ftl (French) * New translations zen-menubar.ftl (Catalan) * New translations zen-menubar.ftl (Hebrew) * New translations zen-menubar.ftl (Hungarian) * New translations zen-menubar.ftl (Korean) * New translations zen-menubar.ftl (Lithuanian) * New translations zen-menubar.ftl (Portuguese) * New translations zen-menubar.ftl (Swedish) * New translations zen-menubar.ftl (Turkish) * New translations zen-menubar.ftl (Chinese Traditional) * New translations zen-menubar.ftl (Icelandic) * New translations zen-menubar.ftl (Portuguese, Brazilian) * New translations zen-menubar.ftl (Welsh) * New translations zen-preferences.ftl (Catalan) * New translations zen-preferences.ftl (Russian) * New translations zen-preferences.ftl (Turkish) * New translations zen-general.ftl (Indonesian) * New translations zen-workspaces.ftl (Chinese Traditional) * New translations zen-menubar.ftl (Chinese Traditional) * New translations zen-menubar.ftl (Indonesian) * New translations zen-workspaces.ftl (Indonesian) * New translations zen-preferences.ftl (Indonesian) * New translations zen-general.ftl (Welsh) * New translations zen-menubar.ftl (French) * New translations zen-menubar.ftl (Irish)	2026-02-05 11:00:01 +01:00
@@ -1 +1 @@
 .83
 .89