gh-15363: Fix boost font shuffle off-by-one index (gh-15365)

Co-authored-by: mr. m <mr.m@tuta.com>

.github/workflows/macos-profile-build.yml

@@ -23,7 +23,6 @@ jobs:
       fail-fast: false
       matrix:
         arch: [x86_64, aarch64]
-
     runs-on: ${{ matrix.arch == 'x86_64' && 'macos-15-intel' || 'macos-26' }}
 
     steps:

.github/workflows/windows-profile-build.yml

@@ -27,7 +27,6 @@ jobs:
       fail-fast: false
       matrix:
         arch: [x86_64, aarch64]
-
     runs-on: ${{ inputs.release-branch == 'release' && 'windows-latest' || 'windows-latest' }}
 
     steps:

configs/common/mozconfig

@@ -53,7 +53,10 @@ fi
 if test "$ZEN_RELEASE"; then
 
   ac_add_options --enable-clang-plugin
-  ac_add_options --enable-bootstrap=-sccache
+  
+  if ! test "$ZEN_DISABLE_BOOTSTRAP"; then
+    ac_add_options --enable-bootstrap=-sccache
+  fi
 
   ac_add_options --enable-optimize
 
@@ -69,16 +72,11 @@ if test "$ZEN_RELEASE"; then
   ac_add_options --disable-geckodriver
   ac_add_options --disable-rust-tests
 
-  if ! test "$ZEN_DISABLE_LTO"; then
-    # only enable full LTO when ZEN_RELEASE_BRANCH is 'release'
-    if test "$ZEN_RELEASE_BRANCH" = "release"; then
-      # TODO: make it "full" once we have the resources to build it
-      export MOZ_LTO=cross,full
-      ac_add_options --enable-lto=cross,full
-    else
-      export MOZ_LTO=cross,thin
-      ac_add_options --enable-lto=cross,thin
-    fi
+  if test "$ZEN_DISABLE_LTO"; then
+    ac_add_options --disable-lto
+  else
+    export MOZ_LTO=cross,thin
+    ac_add_options --enable-lto=cross,thin
   fi
 
   mk_add_options MOZILLA_OFFICIAL=1

configs/linux/mozconfig

@@ -9,6 +9,9 @@ if test "$ZEN_RELEASE"; then
 
         # Enable Profile Guided Optimization
         if ! test "$ZEN_GA_DISABLE_PGO"; then
+            export MOZ_LTO=cross,full
+            ac_add_options --enable-lto=cross,full
+
             if test "$ZEN_GA_GENERATE_PROFILE"; then
                 mk_add_options "export MOZ_AUTOMATION_PACKAGE_GENERATED_SOURCES=0"
                 ac_add_options --enable-profile-generate=cross

configs/windows/mozconfig

@@ -45,6 +45,9 @@ if test "$ZEN_CROSS_COMPILING"; then
       ac_add_options --enable-profile-use=cross
       ac_add_options --with-pgo-profile-path=$(echo ~)/artifact/merged.profdata
       ac_add_options --with-pgo-jarlog=$(echo ~)/artifact/en-US.log
+
+      export MOZ_LTO=cross,full
+      ac_add_options --enable-lto=cross,full
     fi
   fi
 fi

crowdin.yml

@@ -26,3 +26,5 @@ files:
     translation: browser/browser/zen-space-routing.ftl
   - source: en-US/browser/browser/zen-command-palette.ftl
     translation: browser/browser/zen-command-palette.ftl
+  - source: en-US/browser/browser/zen-share.ftl
+    translation: browser/browser/zen-share.ftl

locales/en-US/browser/browser/preferences/zen-preferences.ftl

@@ -68,6 +68,10 @@ zen-settings-workspaces-sync =
     .label = Sync your sidebar across devices
     .description = Keep your workspaces, pinned tabs and folders in sync on all your devices through your Mozilla account.
 
+zen-settings-normal-tabs-sync =
+    .label = Include unpinned tabs
+    .description = Also sync the regular tabs of each space, not just your pinned tabs and folders.
+
 zen-settings-workspaces-sync-unpinned-tabs =
     .label = Sync only pinned tabs in workspaces
 

locales/en-US/browser/browser/zen-share.ftl

@@ -0,0 +1,43 @@
+# 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-share-space =
+    .label = Share Space…
+zen-share-folder =
+    .label = Share Folder…
+zen-share-split-view =
+    .label = Share Split View…
+
+zen-share-link-copied-toast = Share link copied!
+zen-share-link-expires-description = Anyone with the link can open it until { $date }
+zen-share-link-permanent-description = Anyone with the link can open it
+
+zen-share-error-toast = Couldn't create a share link
+zen-share-error-auth-description = The share server rejected your key
+zen-share-error-too-large-description = This share is too big to upload
+zen-share-error-rate-limited-description = You're sharing too fast, try again in a minute
+zen-share-error-network-description = Couldn't reach the share server
+zen-share-error-empty-description = There's nothing shareable here
+zen-share-error-server-description = The share server returned an error
+
+zen-share-overlay-loading = Loading shared tabs…
+zen-share-overlay-from-space = A Space from { $name }
+zen-share-overlay-from-folder = A Folder from { $name }
+zen-share-overlay-shared-with-you = Shared with you
+zen-share-overlay-add-space = Add Space to Zen
+zen-share-overlay-add-folder = Add Folder to Zen
+zen-share-imported-toast = Added to your browser!
+zen-share-import-error-toast = Couldn't import this share
+zen-share-import-error-dead-description = The link has expired or doesn't exist
+zen-share-import-error-invalid-description = The shared data is invalid
+
+zen-share-confirm-title = Share link
+zen-share-confirm-dialog =
+    .buttonlabelaccept = Share
+zen-share-confirm-description = Zen uploads a copy of these tabs to the share server and copies a link anyone can open. The link expires after 30 days.
+zen-share-confirm-anonymous = Sharing is anonymous unless you add a name.
+zen-share-confirm-name-input =
+    .placeholder = Your name (optional)
+zen-share-confirm-dont-ask =
+    .label = Don't ask me again

locales/en-US/browser/browser/zen-welcome.ftl

@@ -24,6 +24,11 @@ zen-welcome-default-search-description = Choose your default search engine. You
 zen-welcome-essentials-title = Choose the apps you use most.
 zen-welcome-essentials-description = Select your favorite apps to keep them handy in your sidebar.
 
+zen-welcome-block-ads-title = Block ads and trackers?
+zen-welcome-block-ads-description = { -brand-short-name } can install uBlock Origin for you, so pages load cleaner and faster. You can remove it any time.
+zen-welcome-block-ads-yes = <strong>YES</strong>, block ads for me.
+zen-welcome-block-ads-no = <strong>NO</strong>, show me everything.
+
 zen-welcome-workspace-colors-title = Your space, your colors.
 zen-welcome-workspace-colors-description = Personalize your browser by giving each space its own unique color identity.
 

prefs/zen/share.yaml

@@ -2,5 +2,18 @@
 # 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/.
 
-- name: zen.share.enabled
+- name: zen.share.base-url
+  value: "https://share.zen-browser.app"
+
+- name: zen.share.secret-key
+  value: ""
+
+- name: zen.share.display-name
+  value: ""
+
+# Allow zen.share.display-name to be synced across devices.
+- name: services.sync.prefs.sync.zen.share.display-name
   value: true
+
+- name: zen.share.dont-ask-before-sharing
+  value: false

prefs/zen/sync.yaml

@@ -8,3 +8,9 @@
 
 - name: zen.spaces-sync.debug
   value: false
+
+- name: zen.spaces-sync.normal-tabs
+  value: false
+
+- name: services.sync.prefs.sync.zen.spaces-sync.normal-tabs
+  value: true

prefs/zen/theme.yaml

@@ -20,6 +20,9 @@
 - name: zen.theme.acrylic-elements
   value: "@IS_TWILIGHT@"
 
+- name: zen.theme.squircle-browser-view
+  value: "@IS_TWILIGHT@"
+
 - name: zen.theme.disable-lightweight
   value: true
 

src/browser/base/content/zen-assets.jar.inc.mn

@@ -21,3 +21,4 @@
 #include ../../../zen/boosts/jar.inc.mn
 #include ../../../zen/live-folders/jar.inc.mn
 #include ../../../zen/space-routing/jar.inc.mn
+#include ../../../zen/share/jar.inc.mn

src/browser/base/content/zen-commands.inc.xhtml

@@ -16,6 +16,7 @@
   <command id="cmd_zenSplitViewUnsplit" />
   <command id="cmd_zenSplitViewLinkInNewTab" />
   <command id="cmd_zenSplitViewContextMenu" />
+  <command id="cmd_zenCtxShareSplitView" />
   <command id="cmd_zenNewEmptySplit" />
 
   <!-- Workspace commands -->
@@ -40,6 +41,7 @@
   <command id="cmd_contextZenRemoveFromEssentials" />
 
   <command id="cmd_zenCtxDeleteWorkspace" />
+  <command id="cmd_zenCtxShareWorkspace" />
   <command id="cmd_zenUnloadWorkspace" />
   <command id="cmd_zenUnloadAllOtherWorkspace" />
   <command id="cmd_zenOpenSpaceRoutingSettings" />

src/browser/base/content/zen-locales.inc.xhtml

@@ -12,4 +12,5 @@
 <link rel="localization" href="browser/zen-boosts.ftl"/>
 <link rel="localization" href="browser/zen-live-folders.ftl"/>
 <link rel="localization" href="browser/zen-space-routing.ftl"/>
+<link rel="localization" href="browser/zen-share.ftl"/>
 </linkset>

src/browser/base/content/zen-panels/popups.inc

@@ -32,6 +32,7 @@
   <menuitem id="context_zenUnloadAllOtherWorkspace" data-l10n-id="zen-workspaces-panel-unload-others" command="cmd_zenUnloadAllOtherWorkspace"/>
   <menuseparator/>
   <menuitem data-l10n-id="zen-panel-ui-workspaces-create" command="cmd_zenOpenWorkspaceCreation"/>
+  <menuitem id="context_zenShareWorkspace" data-l10n-id="zen-share-space" command="cmd_zenCtxShareWorkspace"/>
   <menuitem id="context_zenDeleteWorkspace" data-l10n-id="zen-workspaces-panel-context-delete" command="cmd_zenCtxDeleteWorkspace"/>
   <menuseparator/>
   <menuitem id="context_zenSpaceRoutingSettings" data-l10n-id="zen-space-routing-settings" command="cmd_zenOpenSpaceRoutingSettings"/>
@@ -55,6 +56,7 @@
     <menupopup />
   </menu>
   <menuitem id="context_zenFolderToSpace" data-l10n-id="zen-folders-panel-convert-folder-to-space" />
+  <menuitem id="context_zenShareFolder" data-l10n-id="zen-share-folder"/>
   <menuseparator />
   <menuitem id="context_zenFolderUnpack" data-l10n-id="zen-folders-panel-unpack-folder"/>
   <menuitem id="context_zenFolderDelete" data-l10n-id="zen-folders-panel-delete-folder"/>

src/browser/components/preferences/config/account-sync-mjs.patch

@@ -1,16 +1,17 @@
 diff --git a/browser/components/preferences/config/account-sync.mjs b/browser/components/preferences/config/account-sync.mjs
-index b01fd4bb163ad53139fcbd8e79e12ef994d1fa13..dd60be4fe268618d6596cd5cfac3342975bd241a 100644
+index b01fd4bb163ad53139fcbd8e79e12ef994d1fa13..7e3c2f6852b77192b4505bb3d5a7b58586da6548 100644
 --- a/browser/components/preferences/config/account-sync.mjs
 +++ b/browser/components/preferences/config/account-sync.mjs
-@@ -46,6 +46,7 @@ Preferences.addAll([
+@@ -46,6 +46,8 @@ Preferences.addAll([
    { id: "services.sync.engine.creditcards", type: "bool" },
    { id: "services.sync.engine.addons", type: "bool" },
    { id: "services.sync.engine.prefs", type: "bool" },
 +  { id: "services.sync.engine.spaces", type: "bool" },
++  { id: "zen.spaces-sync.normal-tabs", type: "bool" },
  ]);
  
  /**
-@@ -557,6 +558,7 @@ const SYNC_ENGINE_SETTINGS = [
+@@ -557,6 +559,7 @@ const SYNC_ENGINE_SETTINGS = [
      type: "payments",
    },
    { id: "syncAddons", pref: "services.sync.engine.addons", type: "addons" },
@@ -18,7 +19,7 @@ index b01fd4bb163ad53139fcbd8e79e12ef994d1fa13..dd60be4fe268618d6596cd5cfac33429
    { id: "syncSettings", pref: "services.sync.engine.prefs", type: "settings" },
  ];
  
-@@ -564,6 +566,12 @@ SYNC_ENGINE_SETTINGS.forEach(({ id, pref }) => {
+@@ -564,6 +567,18 @@ SYNC_ENGINE_SETTINGS.forEach(({ id, pref }) => {
    Preferences.addSetting({ id, pref });
  });
  
@@ -27,11 +28,17 @@ index b01fd4bb163ad53139fcbd8e79e12ef994d1fa13..dd60be4fe268618d6596cd5cfac33429
 +  id: "zenSyncWorkspaces",
 +  pref: "services.sync.engine.spaces",
 +});
++Preferences.addSetting({
++  id: "zenSyncNormalTabs",
++  pref: "zen.spaces-sync.normal-tabs",
++  deps: ["zenSyncWorkspaces"],
++  visible: deps => !!deps.zenSyncWorkspaces.value,
++});
 +
  Preferences.addSetting({
    id: "syncEngines",
    deps: SYNC_ENGINE_SETTINGS.map(({ id }) => id),
-@@ -995,6 +1003,20 @@ SettingGroupManager.registerGroups({
+@@ -995,6 +1010,27 @@ SettingGroupManager.registerGroups({
              id: "syncEnginesList",
              control: "sync-engines-list",
            },
@@ -46,6 +53,13 @@ index b01fd4bb163ad53139fcbd8e79e12ef994d1fa13..dd60be4fe268618d6596cd5cfac33429
 +                controlAttrs: {
 +                  inputlayout: "inline-end",
 +                },
++                items: [
++                  {
++                    id: "zenSyncNormalTabs",
++                    l10nId: "zen-settings-normal-tabs-sync",
++                    control: "moz-checkbox",
++                  },
++                ],
 +              },
 +            ],
 +          },

src/browser/components/preferences/main-js.patch

@@ -1,8 +1,8 @@
 diff --git a/browser/components/preferences/main.js b/browser/components/preferences/main.js
-index 88675d1bcbf000b10d85a9c0980bc6069d88052c..ed3a1e809eb0fcccc5a957be7affb77be8978e32 100644
+index 5a56d348146c1c37c088ced60327fffebcf8fac0..abd65594d365fbc0a74af3953c71f410301898ad 100644
 --- a/browser/components/preferences/main.js
 +++ b/browser/components/preferences/main.js
-@@ -528,6 +528,11 @@ function createStartupConfig(hidden = false) {
+@@ -529,6 +529,11 @@ function createStartupConfig(hidden = false) {
            },
          ],
        },
@@ -14,7 +14,7 @@ index 88675d1bcbf000b10d85a9c0980bc6069d88052c..ed3a1e809eb0fcccc5a957be7affb77b
        {
          id: "windowsLaunchOnLogin",
          l10nId: "windows-launch-on-login",
-@@ -575,7 +580,7 @@ function createStartupConfig(hidden = false) {
+@@ -576,7 +581,7 @@ function createStartupConfig(hidden = false) {
  SettingGroupManager.registerGroups({
    defaultBrowser: createDefaultBrowserConfig(),
    startup: createStartupConfig(
@@ -23,7 +23,7 @@ index 88675d1bcbf000b10d85a9c0980bc6069d88052c..ed3a1e809eb0fcccc5a957be7affb77b
    ),
  });
  
-@@ -628,7 +633,7 @@ function getBundleForLocales(newLocales) {
+@@ -636,7 +641,7 @@ function getBundleForLocales(newLocales) {
      ])
    );
    return new Localization(

src/browser/components/preferences/zen-settings.js

@@ -38,9 +38,16 @@ var gZenMarketplaceManager = {
 
     this.__hasInitializedEvents = true;
 
-    await this._buildModsList();
-
     Services.prefs.addObserver(gZenMods.updatePref, this);
+    window.addEventListener(
+      "unload",
+      () => {
+        Services.prefs.removeObserver(gZenMods.updatePref, this);
+      },
+      { once: true }
+    );
+
+    await this._buildModsList();
 
     const checkForUpdateClick = (event) => {
       if (event.target === checkForUpdates) {
@@ -69,7 +76,6 @@ var gZenMarketplaceManager = {
     });
 
     window.addEventListener("unload", () => {
-      Services.prefs.removeObserver(gZenMods.updatePref, this);
       this.__hasInitializedEvents = false;
 
       document.removeEventListener("ZenModsMarketplace:CheckForUpdatesFinished", this);
@@ -735,7 +741,6 @@ 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",
@@ -744,7 +749,6 @@ var gZenWorkspacesSettings = {
     Services.prefs.addObserver("browser.ctrlTab.sortByRecentlyUsed", toggleZenCycleByAttrWarning);
     window.addEventListener("unload", () => {
       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",

src/browser/components/sessionstore/SessionStore-sys-mjs.patch

@@ -1,8 +1,8 @@
 diff --git a/browser/components/sessionstore/SessionStore.sys.mjs b/browser/components/sessionstore/SessionStore.sys.mjs
-index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2ab6e6c967 100644
+index 76a984f6e21409941ea038218d161e67f2e0c23d..52408568a33a89c0e3d0d1514152ded2eaa1afed 100644
 --- a/browser/components/sessionstore/SessionStore.sys.mjs
 +++ b/browser/components/sessionstore/SessionStore.sys.mjs
-@@ -129,6 +129,11 @@ const TAB_EVENTS = [
+@@ -126,6 +126,11 @@ const TAB_EVENTS = [
    "TabSplitViewActivate",
    "SplitViewRemoved",
    "SplitViewCreated",
@@ -14,7 +14,7 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
  ];
  
  const XUL_NS = "http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul";
-@@ -201,6 +206,8 @@ ChromeUtils.defineESModuleGetters(lazy, {
+@@ -198,6 +203,8 @@ ChromeUtils.defineESModuleGetters(lazy, {
    TabStateCache: "resource:///modules/sessionstore/TabStateCache.sys.mjs",
    TabStateFlusher: "resource:///modules/sessionstore/TabStateFlusher.sys.mjs",
    setTimeout: "resource://gre/modules/Timer.sys.mjs",
@@ -23,7 +23,7 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
  });
  
  ChromeUtils.defineLazyGetter(lazy, "blankURI", () => {
-@@ -1317,10 +1324,7 @@ var SessionStoreInternal = {
+@@ -1314,10 +1321,7 @@ var SessionStoreInternal = {
     */
    get willAutoRestore() {
      return (
@@ -35,7 +35,7 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
      );
    },
  
-@@ -2008,6 +2012,11 @@ var SessionStoreInternal = {
+@@ -2005,6 +2009,11 @@ var SessionStoreInternal = {
        case "TabPinned":
        case "TabUnpinned":
        case "SwapDocShells":
@@ -47,7 +47,7 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
          this.saveStateDelayed(win);
          break;
        case "TabGroupCreate":
-@@ -2117,6 +2126,10 @@ var SessionStoreInternal = {
+@@ -2114,6 +2123,10 @@ var SessionStoreInternal = {
        this._windows[aWindow.__SSi].isTaskbarTab = true;
      }
  
@@ -58,7 +58,7 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
      if (lazy.AIWindow.isAIWindowActiveAndEnabled(aWindow)) {
        this._windows[aWindow.__SSi].isAIWindow = true;
      }
-@@ -2153,7 +2166,7 @@ var SessionStoreInternal = {
+@@ -2150,7 +2163,7 @@ var SessionStoreInternal = {
      let isTaskbarTab = this._windows[aWindow.__SSi].isTaskbarTab;
      // A regular window is not a private window, taskbar tab window, or popup window
      let isRegularWindow =
@@ -67,7 +67,7 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
  
      // perform additional initialization when the first window is loading
      if (lazy.RunState.isStopped) {
-@@ -2165,7 +2178,7 @@ var SessionStoreInternal = {
+@@ -2162,7 +2175,7 @@ var SessionStoreInternal = {
          // to disk to NOW() to enforce a full interval before the next write.
          lazy.SessionSaver.updateLastSaveTime();
  
@@ -76,7 +76,7 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
            this._log.debug(
              "initializeWindow, the window is private or a web app. Saving SessionStartup.state for possibly restoring later"
            );
-@@ -2209,6 +2222,7 @@ var SessionStoreInternal = {
+@@ -2206,6 +2219,7 @@ var SessionStoreInternal = {
            null,
            "sessionstore-one-or-no-tab-restored"
          );
@@ -84,7 +84,7 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
          this._deferredAllWindowsRestored.resolve();
        }
        // this window was opened by _openWindowWithState
-@@ -2258,7 +2272,6 @@ var SessionStoreInternal = {
+@@ -2255,7 +2269,6 @@ var SessionStoreInternal = {
        if (closedWindowState) {
          let newWindowState;
          if (
@@ -92,7 +92,7 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
            !lazy.SessionStartup.willRestore()
          ) {
            // We want to split the window up into pinned tabs and unpinned tabs.
-@@ -2294,6 +2307,7 @@ var SessionStoreInternal = {
+@@ -2291,6 +2304,7 @@ var SessionStoreInternal = {
          }
  
          if (newWindowState) {
@@ -100,7 +100,7 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
            // Ensure that the window state isn't hidden
            this._restoreCount = 1;
            let state = { windows: [newWindowState] };
-@@ -2330,6 +2344,9 @@ var SessionStoreInternal = {
+@@ -2327,6 +2341,9 @@ var SessionStoreInternal = {
        });
        this._shouldRestoreLastSession = false;
      }
@@ -110,7 +110,7 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
  
      if (this._restoreLastWindow && aWindow.toolbar.visible) {
        // always reset (if not a popup window)
-@@ -2480,7 +2497,7 @@ var SessionStoreInternal = {
+@@ -2477,7 +2494,7 @@ var SessionStoreInternal = {
  
      var tabbrowser = aWindow.gBrowser;
  
@@ -119,7 +119,7 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
  
      TAB_EVENTS.forEach(function (aEvent) {
        tabbrowser.tabContainer.removeEventListener(aEvent, this, true);
-@@ -2531,7 +2548,7 @@ var SessionStoreInternal = {
+@@ -2528,7 +2545,7 @@ var SessionStoreInternal = {
  
        let isLastRegularWindow =
          Object.values(this._windows).filter(
@@ -128,7 +128,7 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
          ).length == 1;
        this._log.debug(
          `onClose, closing window isLastRegularWindow? ${isLastRegularWindow}`
-@@ -2588,8 +2605,8 @@ var SessionStoreInternal = {
+@@ -2585,8 +2602,8 @@ 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.
@@ -139,7 +139,7 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
        }
  
        completionPromise = lazy.TabStateFlusher.flushWindow(aWindow).then(() => {
-@@ -2609,8 +2626,9 @@ var SessionStoreInternal = {
+@@ -2606,8 +2623,9 @@ var SessionStoreInternal = {
  
          // Save non-private windows if they have at
          // least one saveable tab or are the last window.
@@ -151,7 +151,7 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
  
            if (!isLastWindow && winData.closedId > -1) {
              this._addClosedAction(
-@@ -2686,7 +2704,7 @@ var SessionStoreInternal = {
+@@ -2683,7 +2701,7 @@ var SessionStoreInternal = {
     *        to call this method again asynchronously (for example, after
     *        a window flush).
     */
@@ -160,7 +160,7 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
      // Make sure SessionStore is still running, and make sure that we
      // haven't chosen to forget this window.
      if (
-@@ -2703,6 +2721,7 @@ var SessionStoreInternal = {
+@@ -2700,6 +2718,7 @@ var SessionStoreInternal = {
        // _closedWindows from a previous call to this function.
        let winIndex = this._closedWindows.indexOf(winData);
        let alreadyStored = winIndex != -1;
@@ -168,7 +168,7 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
        // If sidebar command is truthy, i.e. sidebar is open, store sidebar settings
        let shouldStore = hasSaveableTabs || isLastWindow;
  
-@@ -3525,7 +3544,7 @@ var SessionStoreInternal = {
+@@ -3522,7 +3541,7 @@ var SessionStoreInternal = {
      if (!isPrivateWindow && tabState.isPrivate) {
        return;
      }
@@ -177,10 +177,14 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
        return;
      }
  
-@@ -4264,6 +4283,12 @@ var SessionStoreInternal = {
+@@ -4260,7 +4279,15 @@ var SessionStoreInternal = {
+         1,
          Math.min(tabState.index, tabState.entries.length)
        );
-       tabState.pinned = false;
+-      tabState.pinned = false;
++      tabState.pinned =
++        newTab.group?.isZenFolder === true &&
++        Services.prefs.getBoolPref("zen.folders.owned-tabs-in-folder");
 +      tabState.zenEssential = false;
 +      tabState.zenSyncId = null;
 +      tabState.zenIsGlance = false;
@@ -190,7 +194,7 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
  
        if (inBackground === false) {
          aWindow.gBrowser.selectedTab = newTab;
-@@ -4697,6 +4722,8 @@ var SessionStoreInternal = {
+@@ -4694,6 +4721,8 @@ var SessionStoreInternal = {
        // Append the tab if we're opening into a different window,
        tabIndex: aSource == aTargetWindow ? pos : Infinity,
        pinned: state.pinned,
@@ -199,7 +203,7 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
        userContextId: state.userContextId,
        skipLoad: true,
        preferredRemoteType,
-@@ -5194,9 +5221,10 @@ var SessionStoreInternal = {
+@@ -5191,9 +5220,10 @@ var SessionStoreInternal = {
        if (activePageData.title && activePageData.title != activePageData.url) {
          win.gBrowser.setInitialTabTitle(tab, activePageData.title, {
            isContentTitle: true,
@@ -211,7 +215,7 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
        }
      }
  
-@@ -5561,7 +5589,7 @@ var SessionStoreInternal = {
+@@ -5561,7 +5591,7 @@ var SessionStoreInternal = {
  
      for (let i = tabbrowser.pinnedTabCount; i < tabbrowser.tabs.length; i++) {
        let tab = tabbrowser.tabs[i];
@@ -220,7 +224,7 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
          removableTabs.push(tab);
        }
      }
-@@ -5674,7 +5702,7 @@ var SessionStoreInternal = {
+@@ -5674,7 +5704,7 @@ var SessionStoreInternal = {
  
      // collect the data for all windows
      for (ix in this._windows) {
@@ -229,7 +233,7 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
          // window data is still in _statesToRestore
          continue;
        }
-@@ -5818,11 +5846,12 @@ var SessionStoreInternal = {
+@@ -5818,11 +5848,12 @@ var SessionStoreInternal = {
      }
  
      let tabbrowser = aWindow.gBrowser;
@@ -243,7 +247,7 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
      // update the internal state data for this window
      for (let tab of tabs) {
        if (tab == aWindow.FirefoxViewHandler.tab) {
-@@ -5833,6 +5862,9 @@ var SessionStoreInternal = {
+@@ -5833,6 +5864,9 @@ var SessionStoreInternal = {
        tabsData.push(tabData);
      }
  
@@ -253,7 +257,7 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
      // update tab group state for this window
      winData.groups = [];
      for (let tabGroup of aWindow.gBrowser.tabGroups) {
-@@ -5849,7 +5881,7 @@ var SessionStoreInternal = {
+@@ -5849,7 +5883,7 @@ 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) {
@@ -262,7 +266,7 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
        winData.title = tabbrowser.tabs[0].label;
      }
      winData.selected = selectedIndex;
-@@ -6051,8 +6083,8 @@ var SessionStoreInternal = {
+@@ -6051,8 +6085,8 @@ var SessionStoreInternal = {
      // selectTab represents.
      let selectTab = 0;
      if (overwriteTabs) {
@@ -273,7 +277,7 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
        selectTab = Math.min(selectTab, winData.tabs.length);
      }
  
-@@ -6074,6 +6106,7 @@ var SessionStoreInternal = {
+@@ -6074,6 +6108,7 @@ var SessionStoreInternal = {
      if (overwriteTabs) {
        for (let i = tabbrowser.browsers.length - 1; i >= 0; i--) {
          if (!tabbrowser.tabs[i].selected) {
@@ -281,7 +285,7 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
            tabbrowser.removeTab(tabbrowser.tabs[i]);
          }
        }
-@@ -6108,6 +6141,12 @@ var SessionStoreInternal = {
+@@ -6108,6 +6143,12 @@ var SessionStoreInternal = {
          savedTabGroup => !openTabGroupIdsInWindow.has(savedTabGroup.id)
        );
      }
@@ -294,7 +298,7 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
  
      // Move the originally open tabs to the end.
      if (initialTabs) {
-@@ -6674,6 +6713,25 @@ var SessionStoreInternal = {
+@@ -6674,6 +6715,25 @@ var SessionStoreInternal = {
  
      // Most of tabData has been restored, now continue with restoring
      // attributes that may trigger external events.
@@ -320,7 +324,7 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
  
      if (tabData.pinned) {
        tabbrowser.pinTab(tab);
-@@ -6859,6 +6917,9 @@ var SessionStoreInternal = {
+@@ -6859,6 +6919,9 @@ var SessionStoreInternal = {
          aWindow.gURLBar.readOnly = false;
        }
      }
@@ -330,7 +334,14 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
  
      let promiseParts = Promise.withResolvers();
      aWindow.setTimeout(() => {
-@@ -7654,7 +7715,7 @@ var SessionStoreInternal = {
+@@ -7356,5 +7419,6 @@ var SessionStoreInternal = {
+    */
+   _isCmdLineEmpty: function ssi_isCmdLineEmpty(aWindow, aState) {
+     var pinnedOnly =
++      !Services.prefs.getBoolPref("zen.workspaces.continue-where-left-off") &&
+       aState.windows &&
+       aState.windows.every(win => win.tabs.every(tab => tab.pinned));
+@@ -7654,7 +7718,7 @@ var SessionStoreInternal = {
  
        let groupsToSave = new Map();
        for (let tIndex = 0; tIndex < window.tabs.length; ) {
@@ -339,7 +350,7 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
            // Adjust window.selected
            if (tIndex + 1 < window.selected) {
              window.selected -= 1;
-@@ -7669,7 +7730,7 @@ var SessionStoreInternal = {
+@@ -7669,7 +7733,7 @@ var SessionStoreInternal = {
            );
            // We don't want to increment tIndex here.
            continue;
@@ -348,7 +359,7 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
            // Convert any open groups into saved groups.
            let groupStateToSave = window.groups.find(
              groupState => groupState.id == window.tabs[tIndex].groupId
-@@ -8233,7 +8294,6 @@ var SessionStoreInternal = {
+@@ -8233,7 +8297,6 @@ var SessionStoreInternal = {
      timer.initWithCallback(
        function () {
          if (beats <= 0) {
@@ -356,7 +367,7 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
            Glean.sessionRestore.shutdownFlushAllOutcomes.timed_out.add(1);
            deferred.resolve();
          }
-@@ -8711,6 +8771,7 @@ var SessionStoreInternal = {
+@@ -8711,6 +8774,7 @@ var SessionStoreInternal = {
      if (
        !savedTabGroupState.tabs.length ||
        this.getSavedTabGroup(savedTabGroupState.id)

src/browser/components/sessionstore/TabState-sys-mjs.patch

@@ -1,5 +1,5 @@
 diff --git a/browser/components/sessionstore/TabState.sys.mjs b/browser/components/sessionstore/TabState.sys.mjs
-index a33deeb5b587d6a950960a1a4781176e4e730ad7..e96cfb9a5ffbe4feccdffa8b6d18ececb48d4c52 100644
+index a33deeb5b587d6a950960a1a4781176e4e730ad7..7927471d389f2626e4cc1b0e7a6eab6446dca432 100644
 --- a/browser/components/sessionstore/TabState.sys.mjs
 +++ b/browser/components/sessionstore/TabState.sys.mjs
 @@ -8,6 +8,7 @@ ChromeUtils.defineESModuleGetters(lazy, {
@@ -39,3 +39,14 @@ index a33deeb5b587d6a950960a1a4781176e4e730ad7..e96cfb9a5ffbe4feccdffa8b6d18ecec
  
      tabData.userContextId = tab.userContextId || 0;
  
+@@ -132,6 +151,10 @@ class _TabState {
+       tabData.image = tabbrowser.getIcon(tab);
+     }
+ 
++    if (tab.zenStaticIcon) {
++      tabData.image = tab.zenStaticIcon;
++    }
++
+     // If there is a userTypedValue set, then either the user has typed something
+     // in the URL bar, or a new tab was opened with a URI to load.
+     // If so, we also track whether we were still in the process of loading something.

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 43180487a2fac15b7a65fac94f233eeed9094990..ae1288974cae29da929f27b78ff8db542566eba2 100644
+index 43180487a2fac15b7a65fac94f233eeed9094990..ef6d30eb681caeae48d15280687b3bc37dbadc37 100644
 --- a/browser/components/tabbrowser/content/tabbrowser.js
 +++ b/browser/components/tabbrowser/content/tabbrowser.js
 @@ -514,6 +514,7 @@
@@ -523,7 +523,7 @@ index 43180487a2fac15b7a65fac94f233eeed9094990..ae1288974cae29da929f27b78ff8db54
 +        } else {
 +          gZenWorkspaces._tabToRemoveForEmpty = leftoverTab;
 +          if (Services.prefs.getBoolPref("zen.workspaces.continue-where-left-off")) {
-+            gZenWorkspaces._tabToSelect = selectTab - 2; // -1 for the offset, and another -1 for the empty tab.
++            gZenWorkspaces._tabToSelect = selectTab - 1; // -1 for the empty tab.
 +          }
 +          if (gZenWorkspaces._initialTab && !gZenVerticalTabsManager._canReplaceNewTab) {
 +            gZenWorkspaces._initialTab._shouldRemove = true;
@@ -751,7 +751,7 @@ index 43180487a2fac15b7a65fac94f233eeed9094990..ae1288974cae29da929f27b78ff8db54
      }
  
      /**
-@@ -6422,6 +6618,7 @@
+@@ -6422,11 +6618,12 @@
        }
  
        let excludeTabs = new Set(aExcludeTabs);
@@ -759,6 +759,12 @@ index 43180487a2fac15b7a65fac94f233eeed9094990..ae1288974cae29da929f27b78ff8db54
  
        // If this tab has a successor, it should be selectable, since
        // hiding or closing a tab removes that tab as a successor.
+       if (aTab.successor && !excludeTabs.has(aTab.successor)) {
+-        return aTab.successor;
++        return gZenWorkspaces.findTabToBlur(aTab.successor);
+       }
+ 
+       if (
 @@ -6434,13 +6631,13 @@
          !excludeTabs.has(aTab.owner) &&
          Services.prefs.getBoolPref("browser.tabs.selectOwnerOnClose")
@@ -984,7 +990,7 @@ index 43180487a2fac15b7a65fac94f233eeed9094990..ae1288974cae29da929f27b78ff8db54
 +      if (!gZenFolders.canDropElement(element, targetElement)) {
 +        element = element.group;
 +      }
-+      if (!element.hasAttribute('zen-essential') && targetElement?.hasAttribute('zen-essential')) { 
++      if (!element.hasAttribute('zen-essential') && targetElement?.hasAttribute('zen-essential')) {
 +        targetElement = null;
 +        moveBefore = false;
 +      }

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 319fb6870ec18d87b9f1263bd960edaa39b0447c..554cc90fb2307450ddc68033968cefd1a95e28b8 100644
+index 319fb6870ec18d87b9f1263bd960edaa39b0447c..1746a052c304e7988447fdb869ad2e36d7d74e8e 100644
 --- a/browser/components/urlbar/content/UrlbarInput.mjs
 +++ b/browser/components/urlbar/content/UrlbarInput.mjs
 @@ -88,6 +88,13 @@ const lazy = XPCOMUtils.declareLazy({
@@ -61,7 +61,17 @@ index 319fb6870ec18d87b9f1263bd960edaa39b0447c..554cc90fb2307450ddc68033968cefd1
    }
  
    /**
-@@ -1726,7 +1755,11 @@ ${
+@@ -1255,6 +1284,9 @@ ${
+       where,
+       query: searchString,
+     });
++    if (where != "current" && this.sapName != "searchbar") {
++      this.handleRevert();
++    }
+     this.controller.openSERP(
+       engine.id,
+       searchString,
+@@ -1726,7 +1758,11 @@ ${
      openParams.avoidBrowserFocus = keepViewOpen;
  
      if (!this.#providesSearchMode(result) && !keepViewOpen) {
@@ -74,7 +84,7 @@ index 319fb6870ec18d87b9f1263bd960edaa39b0447c..554cc90fb2307450ddc68033968cefd1
      }
  
      if (isCanonized) {
-@@ -3016,6 +3049,42 @@ ${
+@@ -3016,6 +3052,42 @@ ${
      await this.#updateLayoutBreakoutDimensions();
    }
  
@@ -117,7 +127,7 @@ index 319fb6870ec18d87b9f1263bd960edaa39b0447c..554cc90fb2307450ddc68033968cefd1
    startLayoutExtend() {
      if (!this.#allowBreakout || this.hasAttribute("breakout-extend")) {
        // Do not expand if the Urlbar does not support being expanded or it is
-@@ -3030,6 +3099,13 @@ ${
+@@ -3030,6 +3102,13 @@ ${
      this.toggleAttribute("breakout-extend", true);
      this.#updateTextboxPosition();
  
@@ -131,7 +141,7 @@ index 319fb6870ec18d87b9f1263bd960edaa39b0447c..554cc90fb2307450ddc68033968cefd1
      // 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")) {
-@@ -3053,6 +3129,29 @@ ${
+@@ -3053,6 +3132,29 @@ ${
        return;
      }
  
@@ -161,7 +171,7 @@ index 319fb6870ec18d87b9f1263bd960edaa39b0447c..554cc90fb2307450ddc68033968cefd1
      this.toggleAttribute("breakout-extend", false);
      this.#updateTextboxPosition();
    }
-@@ -3091,7 +3190,7 @@ ${
+@@ -3091,7 +3193,7 @@ ${
      forceUnifiedSearchButtonAvailable = false
    ) {
      let prevState = this.getAttribute("pageproxystate");
@@ -170,7 +180,7 @@ index 319fb6870ec18d87b9f1263bd960edaa39b0447c..554cc90fb2307450ddc68033968cefd1
      this.setAttribute("pageproxystate", state);
      this._inputContainer.setAttribute("pageproxystate", state);
      this._identityBox?.setAttribute("pageproxystate", state);
-@@ -3355,10 +3454,12 @@ ${
+@@ -3355,10 +3457,12 @@ ${
      }
  
      this.style.top = px(
@@ -183,7 +193,7 @@ index 319fb6870ec18d87b9f1263bd960edaa39b0447c..554cc90fb2307450ddc68033968cefd1
      );
    }
  
-@@ -3417,9 +3518,10 @@ ${
+@@ -3417,9 +3521,10 @@ ${
            return;
          }
  
@@ -195,7 +205,7 @@ index 319fb6870ec18d87b9f1263bd960edaa39b0447c..554cc90fb2307450ddc68033968cefd1
          );
  
          if (this.#breakoutBlockerCount) {
-@@ -3929,6 +4031,7 @@ ${
+@@ -3929,6 +4034,7 @@ ${
    }
  
    _toggleActionOverride(event) {
@@ -203,7 +213,7 @@ index 319fb6870ec18d87b9f1263bd960edaa39b0447c..554cc90fb2307450ddc68033968cefd1
      if (
        event.keyCode == KeyEvent.DOM_VK_SHIFT ||
        event.keyCode == KeyEvent.DOM_VK_ALT ||
-@@ -4027,9 +4130,10 @@ ${
+@@ -4027,9 +4133,10 @@ ${
      if (!this.#isAddressbar) {
        return val;
      }
@@ -217,7 +227,7 @@ index 319fb6870ec18d87b9f1263bd960edaa39b0447c..554cc90fb2307450ddc68033968cefd1
      // Only trim value if the directionality doesn't change to RTL and we're not
      // showing a strikeout https protocol.
      return this.controller.isTextDirectionRTL(trimmedValue) ||
-@@ -4235,6 +4339,11 @@ ${
+@@ -4235,6 +4342,11 @@ ${
      keepViewOpen = false,
      browserId = null,
    }) {
@@ -229,7 +239,7 @@ index 319fb6870ec18d87b9f1263bd960edaa39b0447c..554cc90fb2307450ddc68033968cefd1
      let userTypedValue;
      if (this.#isAddressbar && where == "current") {
        // Make sure URL is formatted properly (don't show punycode).
-@@ -4576,6 +4685,7 @@ ${
+@@ -4576,6 +4688,7 @@ ${
        this.setResultForCurrentValue(null);
        this.handleCommand();
        this.controller.clearLastQueryContextCache();
@@ -237,7 +247,7 @@ index 319fb6870ec18d87b9f1263bd960edaa39b0447c..554cc90fb2307450ddc68033968cefd1
  
        this._suppressStartQuery = false;
      });
-@@ -4583,7 +4693,6 @@ ${
+@@ -4583,7 +4696,6 @@ ${
      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 +255,7 @@ index 319fb6870ec18d87b9f1263bd960edaa39b0447c..554cc90fb2307450ddc68033968cefd1
  
        let controller =
          this.document.commandDispatcher.getControllerForCommand("cmd_paste");
-@@ -4850,7 +4959,11 @@ ${
+@@ -4850,7 +4962,11 @@ ${
      if (!engineName && !source && !this.hasAttribute("searchmode")) {
        return;
      }
@@ -258,7 +268,7 @@ index 319fb6870ec18d87b9f1263bd960edaa39b0447c..554cc90fb2307450ddc68033968cefd1
      if (this._searchModeIndicatorTitle) {
        this._searchModeIndicatorTitle.textContent = "";
        this._searchModeIndicatorTitle.removeAttribute("data-l10n-id");
-@@ -5149,6 +5262,7 @@ ${
+@@ -5149,6 +5265,7 @@ ${
  
      this.document.l10n.setAttributes(
        this.inputField,
@@ -266,7 +276,7 @@ index 319fb6870ec18d87b9f1263bd960edaa39b0447c..554cc90fb2307450ddc68033968cefd1
        l10nId,
        l10nId == "urlbar-placeholder-with-name"
          ? { name: engineName }
-@@ -5199,6 +5313,12 @@ ${
+@@ -5199,6 +5316,12 @@ ${
      }
  
      lazy.logger.debug("Blur Event");
@@ -279,7 +289,7 @@ index 319fb6870ec18d87b9f1263bd960edaa39b0447c..554cc90fb2307450ddc68033968cefd1
      // We cannot count every blur events after a missed engagement as abandoment
      // because the user may have clicked on some view element that executes
      // a command causing a focus change. For example opening preferences from
-@@ -5276,6 +5396,11 @@ ${
+@@ -5276,6 +5399,11 @@ ${
    }
  
    _on_click(event) {
@@ -291,7 +301,7 @@ index 319fb6870ec18d87b9f1263bd960edaa39b0447c..554cc90fb2307450ddc68033968cefd1
      switch (event.target) {
        case this.inputField:
        case this._inputContainer:
-@@ -5371,10 +5496,11 @@ ${
+@@ -5371,10 +5499,11 @@ ${
        }
        if (untrim) {
          this.setValue(this._untrimmedValue);
@@ -304,7 +314,7 @@ index 319fb6870ec18d87b9f1263bd960edaa39b0447c..554cc90fb2307450ddc68033968cefd1
        this.view.autoOpen({ event });
      } else {
        if (this._untrimOnFocusAfterKeydown) {
-@@ -5414,9 +5540,16 @@ ${
+@@ -5414,9 +5543,16 @@ ${
    }
  
    _on_mousedown(event) {
@@ -322,7 +332,7 @@ index 319fb6870ec18d87b9f1263bd960edaa39b0447c..554cc90fb2307450ddc68033968cefd1
          if (
            event.composedTarget != this.inputField &&
            event.composedTarget != this._inputContainer
-@@ -5426,6 +5559,10 @@ ${
+@@ -5426,6 +5562,10 @@ ${
  
          this.focusedViaMousedown = !this.focused;
          this.#preventClickSelectsAll = this.focused;
@@ -333,7 +343,7 @@ index 319fb6870ec18d87b9f1263bd960edaa39b0447c..554cc90fb2307450ddc68033968cefd1
  
          // Keep the focus status, since the attribute may be changed
          // upon calling this.focus().
-@@ -5463,7 +5600,7 @@ ${
+@@ -5463,7 +5603,7 @@ ${
          // view open on tab switch, and the TabSelect event arrived earlier.
          // Also ignore mousedown on the urlbarView context menu: opening/closing the
          // view is already handled by the result opening flow.
@@ -342,7 +352,7 @@ index 319fb6870ec18d87b9f1263bd960edaa39b0447c..554cc90fb2307450ddc68033968cefd1
            break;
          }
  
-@@ -5754,7 +5891,7 @@ ${
+@@ -5754,7 +5894,7 @@ ${
      // When we are in actions search mode we can show more results so
      // increase the limit.
      let maxResults =

src/browser/extensions/newtab/lib/AboutPreferences-sys-mjs.patch

@@ -0,0 +1,13 @@
+diff --git a/browser/extensions/newtab/lib/AboutPreferences.sys.mjs b/browser/extensions/newtab/lib/AboutPreferences.sys.mjs
+index 4562efc05b76d5dddd35bda79bd7d5d98a51ffc9..ad9b6f55f5e77065ce74535daf6457a5c4b44058 100644
+--- a/browser/extensions/newtab/lib/AboutPreferences.sys.mjs
++++ b/browser/extensions/newtab/lib/AboutPreferences.sys.mjs
+@@ -355,7 +355,7 @@ export class AboutPreferences {
+       // Firefox 155+ registers `homepage` and `customHomepage` in
+       // components/preferences. They can't be registered twice, so skip them
+       // on 155+. Drop this condition once 155 reaches Release.
+-      if (Services.vc.compare(AppConstants.MOZ_APP_VERSION, "155.0a1") < 0) {
++      if (false) {
+         groups.homepage = this._setupHomepageGroup(window);
+         groups.customHomepage = this._setupCustomHomepageGroup(window);
+       }

src/external-patches/firefox/bug_2063169/D319577.patch

@@ -0,0 +1,558 @@
+diff --git a/gfx/wr/webrender/res/ps_quad_mask.glsl b/gfx/wr/webrender/res/ps_quad_mask.glsl
+--- a/gfx/wr/webrender/res/ps_quad_mask.glsl
++++ b/gfx/wr/webrender/res/ps_quad_mask.glsl
+@@ -19,12 +19,14 @@
+ // We pack 4 vec3 clip planes into 3 vec4 to save a varying slot.
+ flat varying highp vec4 vClipPlane_A;
+ flat varying highp vec4 vClipPlane_B;
+ flat varying highp vec4 vClipPlane_C;
+ 
++#ifdef WR_FEATURE_SUPERELLIPSE
+ flat varying highp vec4 vClipShape;
+ flat varying highp vec4 vClipClampedInset;
++#endif
+ 
+ #endif
+ flat varying highp vec2 vClipMode;
+ 
+ #ifdef WR_VERTEX_SHADER
+@@ -40,12 +42,14 @@
+     vec4 radii;
+ #else
+     vec4 radii_top;
+     vec4 radii_bottom;
+ 
++#ifdef WR_FEATURE_SUPERELLIPSE
+     vec4 shape;
+     vec4 inset;
++#endif
+ #endif
+     float mode;
+     int space;
+ };
+ 
+@@ -58,22 +62,29 @@
+     vec4 texels[3] = fetch_from_gpu_buffer_3f(index);
+     clip.rect = RectWithEndpoint(texels[0].xy, texels[0].zw);
+     clip.radii = texels[1];
+     clip.mode = texels[2].x;
+ #else
++#ifdef WR_FEATURE_SUPERELLIPSE
+     vec4 texels[6] = fetch_from_gpu_buffer_6f(index);
++#else
++    vec4 texels[4] = fetch_from_gpu_buffer_4f(index);
++#endif
+     clip.rect = RectWithEndpoint(texels[0].xy, texels[0].zw);
+     clip.radii_top = texels[1];
+     clip.radii_bottom = texels[2];
+     clip.mode = texels[3].x;
++#ifdef WR_FEATURE_SUPERELLIPSE
+     clip.shape = texels[4];
+     clip.inset = texels[5];
++#endif
+ #endif
+ 
+     return clip;
+ }
+ 
++#ifdef WR_FEATURE_SUPERELLIPSE
+ vec4 precalc_corner(vec2 center, vec2 radii, vec2 inset, vec2 clip_sign, float k) {
+     if (k == 1.0) {
+         // round/ellipse corner, precalc the ellipse parameters
+         return vec4(center, inverse_radii_squared(radii));
+     } else {
+@@ -85,10 +96,11 @@
+             radii = offset_radii.zw;
+         }
+         return vec4(center, inverse_radii(radii));
+     }
+ }
++#endif
+ 
+ void pattern_vertex(PrimitiveInfo prim_info) {
+ 
+     Clip clip = fetch_clip(aClipData.y);
+     Transform clip_transform = fetch_transform(aClipData.x);
+@@ -121,10 +133,11 @@
+     vec2 r_tl = clip.radii_top.xy;
+     vec2 r_tr = clip.radii_top.zw;
+     vec2 r_br = clip.radii_bottom.zw;
+     vec2 r_bl = clip.radii_bottom.xy;
+ 
++#ifdef WR_FEATURE_SUPERELLIPSE
+     vClipCenter_Radius_TL = precalc_corner(clip.rect.p0 + r_tl,
+                                            r_tl,
+                                            clip.inset.wx,
+                                            vec2(-1.0, -1.0),
+                                            clip.shape.x);
+@@ -146,10 +159,25 @@
+                                                 clip.rect.p1.y - r_bl.y),
+                                            r_bl,
+                                            clip.inset.wz,
+                                            vec2(-1.0, 1.0),
+                                            clip.shape.w);
++#else
++    vClipCenter_Radius_TL = vec4(clip.rect.p0 + r_tl,
++                                 inverse_radii_squared(r_tl));
++
++    vClipCenter_Radius_TR = vec4(clip.rect.p1.x - r_tr.x,
++                                 clip.rect.p0.y + r_tr.y,
++                                 inverse_radii_squared(r_tr));
++
++    vClipCenter_Radius_BR = vec4(clip.rect.p1 - r_br,
++                                 inverse_radii_squared(r_br));
++
++    vClipCenter_Radius_BL = vec4(clip.rect.p0.x + r_bl.x,
++                                 clip.rect.p1.y - r_bl.y,
++                                 inverse_radii_squared(r_bl));
++#endif
+ 
+     // We need to know the half-spaces of the corners separate from the center
+     // and radius. We compute a point that falls on the diagonal (which is just
+     // an inner vertex pushed out along one axis, but not on both) to get the
+     // plane offset of the half-space. We also compute the direction vector of
+@@ -170,13 +198,15 @@
+ 
+     vClipPlane_A = vec4(tl.x, tl.y, tl.z, tr.x);
+     vClipPlane_B = vec4(tr.y, tr.z, br.x, br.y);
+     vClipPlane_C = vec4(br.z, bl.x, bl.y, bl.z);
+ 
++#ifdef WR_FEATURE_SUPERELLIPSE
+     vClipShape = clip.shape;
+     vClipClampedInset = min(clip.inset, 0.0);
+ #endif
++#endif
+ 
+ }
+ #endif
+ 
+ #ifdef WR_FRAGMENT_SHADER
+@@ -205,11 +235,13 @@
+     vec3 plane_tr = vec3(vClipPlane_A.w, vClipPlane_B.x, vClipPlane_B.y);
+     vec3 plane_br = vec3(vClipPlane_B.z, vClipPlane_B.w, vClipPlane_C.x);
+     vec3 plane_bl = vec3(vClipPlane_C.y, vClipPlane_C.z, vClipPlane_C.w);
+ 
+     float dist;
++#ifdef WR_FEATURE_SUPERELLIPSE
+     if (vClipShape == vec4(1.0)) {
++#endif
+         dist = distance_to_rounded_rect(
+             clip_local_pos,
+             plane_tl,
+             vClipCenter_Radius_TL,
+             plane_tr,
+@@ -218,10 +250,11 @@
+             vClipCenter_Radius_BR,
+             plane_bl,
+             vClipCenter_Radius_BL,
+             vTransformBounds
+         );
++#ifdef WR_FEATURE_SUPERELLIPSE
+     } else {
+         dist = distance_to_shaped_rect(
+             clip_local_pos,
+             vClipCenter_Radius_TL,
+             vClipCenter_Radius_TR,
+@@ -230,10 +263,11 @@
+             vTransformBounds,
+             vClipShape,
+             vClipClampedInset
+         );
+     }
++#endif
+ #endif
+ 
+     // Compute AA for the given dist and range.
+     float alpha = distance_aa(aa_range, dist);
+ 
+@@ -340,13 +374,13 @@
+         #define AA_RECT(local_pos) \
+             sd_round_box(local_pos, v_clip_size, v_clip_radii)
+     #else
+         // The span fast path only handles elliptical corners. For superellipse
+         // shapes, bail out and let SWGL fall back to the fragment shader.
+-        if (vClipShape != vec4(1.0)) {
++        #ifdef WR_FEATURE_SUPERELLIPSE
+             return;
+-        }
++        #endif
+ 
+         // Unpack the corner half-spaces packed into vClipPlane_A/B/C.
+         vec3 plane_tl = vec3(vClipPlane_A.x, vClipPlane_A.y, vClipPlane_A.z);
+         vec3 plane_tr = vec3(vClipPlane_A.w, vClipPlane_B.x, vClipPlane_B.y);
+         vec3 plane_br = vec3(vClipPlane_B.z, vClipPlane_B.w, vClipPlane_C.x);
+diff --git a/gfx/wr/webrender/src/batch.rs b/gfx/wr/webrender/src/batch.rs
+--- a/gfx/wr/webrender/src/batch.rs
++++ b/gfx/wr/webrender/src/batch.rs
+@@ -1224,25 +1224,29 @@
+ /// A list of clip instances to be drawn into a target.
+ #[cfg_attr(feature = "capture", derive(Serialize))]
+ #[cfg_attr(feature = "replay", derive(Deserialize))]
+ pub struct ClipMaskInstanceList {
+     pub mask_instances_fast: FrameVec<MaskInstance>,
++    pub mask_instances_superellipse: FrameVec<MaskInstance>,
+     pub mask_instances_slow: FrameVec<MaskInstance>,
+ 
+     pub mask_instances_fast_with_scissor: FastHashMap<DeviceIntRect, FrameVec<MaskInstance>>,
++    pub mask_instances_superellipse_with_scissor: FastHashMap<DeviceIntRect, FrameVec<MaskInstance>>,
+     pub mask_instances_slow_with_scissor: FastHashMap<DeviceIntRect, FrameVec<MaskInstance>>,
+ 
+     pub image_mask_instances: FastHashMap<TextureSource, FrameVec<PrimitiveInstanceData>>,
+     pub image_mask_instances_with_scissor: FastHashMap<(DeviceIntRect, TextureSource), FrameVec<PrimitiveInstanceData>>,
+ }
+ 
+ impl ClipMaskInstanceList {
+     pub fn new(memory: &FrameMemory) -> Self {
+         ClipMaskInstanceList {
+             mask_instances_fast: memory.new_vec(),
++            mask_instances_superellipse: memory.new_vec(),
+             mask_instances_slow: memory.new_vec(),
+             mask_instances_fast_with_scissor: FastHashMap::default(),
++            mask_instances_superellipse_with_scissor: FastHashMap::default(),
+             mask_instances_slow_with_scissor: FastHashMap::default(),
+             image_mask_instances: FastHashMap::default(),
+             image_mask_instances_with_scissor: FastHashMap::default(),
+         }
+     }
+@@ -1250,20 +1254,24 @@
+     pub fn is_empty(&self) -> bool {
+         // Destructure self to make sure we don't forget to update this method if
+         // a new member is added.
+         let ClipMaskInstanceList {
+             mask_instances_fast,
++            mask_instances_superellipse,
+             mask_instances_slow,
+             mask_instances_fast_with_scissor,
++            mask_instances_superellipse_with_scissor,
+             mask_instances_slow_with_scissor,
+             image_mask_instances,
+             image_mask_instances_with_scissor,
+         } = self;
+ 
+         mask_instances_fast.is_empty()
++            && mask_instances_superellipse.is_empty()
+             && mask_instances_slow.is_empty()
+             && mask_instances_fast_with_scissor.is_empty()
++            && mask_instances_superellipse_with_scissor.is_empty()
+             && mask_instances_slow_with_scissor.is_empty()
+             && image_mask_instances.is_empty()
+             && image_mask_instances_with_scissor.is_empty()
+     }
+ }
+diff --git a/gfx/wr/webrender/src/quad.rs b/gfx/wr/webrender/src/quad.rs
+--- a/gfx/wr/webrender/src/quad.rs
++++ b/gfx/wr/webrender/src/quad.rs
+@@ -1807,11 +1807,11 @@
+     gpu_buffer: &mut GpuBufferBuilderF,
+     clip_rect: LayoutRect,
+     radius: &BorderRadius,
+     inset: LayoutSideOffsets,
+     mode: ClipMode,
+-) -> (GpuBufferAddress, bool) {
++) -> (GpuBufferAddress, bool, bool) {
+     let radius = clamped_radius(radius, clip_rect.size());
+ 
+     if radius.can_use_fast_path_in(&clip_rect) {
+         let mut writer = gpu_buffer.write_blocks(3);
+         writer.push_one(clip_rect);
+@@ -1821,13 +1821,15 @@
+             radius.bottom_left.width,
+             radius.top_left.width,
+         ]);
+         writer.push_one([mode as i32 as f32, 0.0, 0.0, 0.0]);
+ 
+-        (writer.finish(), true)
++        (writer.finish(), true, false)
+     } else {
+-        let mut writer = gpu_buffer.write_blocks(6);
++        let superellipse = !radius.shapes_all_round();
++        let block_count = if superellipse { 6 } else { 4 };
++        let mut writer = gpu_buffer.write_blocks(block_count);
+         writer.push_one(clip_rect);
+         writer.push_one([
+             radius.top_left.width,
+             radius.top_left.height,
+             radius.top_right.width,
+@@ -1838,19 +1840,21 @@
+             radius.bottom_left.height,
+             radius.bottom_right.width,
+             radius.bottom_right.height,
+         ]);
+         writer.push_one([mode as i32 as f32, 0.0, 0.0, 0.0]);
+-        writer.push_one([
+-            radius.shape_top_left,
+-            radius.shape_top_right,
+-            radius.shape_bottom_right,
+-            radius.shape_bottom_left,
+-        ]);
+-        writer.push_one(inset);
++        if superellipse {
++            writer.push_one([
++                radius.shape_top_left,
++                radius.shape_top_right,
++                radius.shape_bottom_right,
++                radius.shape_bottom_left,
++            ]);
++            writer.push_one(inset);
++        }
+ 
+-        (writer.finish(), false)
++        (writer.finish(), false, superellipse)
+     }
+ }
+ 
+ pub fn prepare_clip_task(
+     clip_instance: &ClipNodeInstance,
+@@ -1865,11 +1869,11 @@
+     gpu_buffer: &mut GpuBufferBuilderF,
+     transforms: &mut TransformPalette,
+     rg_builder: &mut RenderTaskGraphBuilder,
+     sub_tasks: &mut SubTaskRange,
+ ) {
+-    let (clip_address, fast_path) = match clip_item.kind {
++    let (clip_address, fast_path, superellipse) = match clip_item.kind {
+         ClipItemKind::RoundedRectangle { radius, inset, mode } => {
+             write_rounded_rect_clip_blocks(
+                 gpu_buffer,
+                 clip_instance.clip_rect,
+                 &radius,
+@@ -1882,11 +1886,11 @@
+             writer.push_one(clip_instance.clip_rect);
+             writer.push_one([0.0, 0.0, 0.0, 0.0]);
+             writer.push_one([mode as i32 as f32, 0.0, 0.0, 0.0]);
+             let clip_address = writer.finish();
+ 
+-            (clip_address, true)
++            (clip_address, true, false)
+         }
+         ClipItemKind::Image { .. } => {
+             let transform_id = transforms.gpu.get_id_with_post_scale(
+                 clip_instance.spatial_node_index,
+                 raster_spatial_node_index,
+@@ -2033,10 +2037,11 @@
+             clip_transform_id,
+             quad_flags,
+             clip_space,
+             needs_scissor_rect,
+             rounded_rect_fast_path: fast_path,
++            rounded_rect_superellipse: superellipse,
+         }),
+     );
+ }
+ 
+ fn create_quad_primitive(
+diff --git a/gfx/wr/webrender/src/render_target.rs b/gfx/wr/webrender/src/render_target.rs
+--- a/gfx/wr/webrender/src/render_target.rs
++++ b/gfx/wr/webrender/src/render_target.rs
+@@ -441,11 +441,11 @@
+                 // so the target must be initialized to one.
+                 self.clears.push((target_rect, ColorF::WHITE));
+ 
+                 let device_rect = DeviceRect::from_size(target_rect.size().to_f32());
+ 
+-                let (clip_address, fast_path) = quad::write_rounded_rect_clip_blocks(
++                let (clip_address, fast_path, superellipse) = quad::write_rounded_rect_clip_blocks(
+                     &mut gpu_buffer_builder.f32,
+                     region_task.clip_rect,
+                     &region_task.radius,
+                     region_task.inset,
+                     region_task.mode,
+@@ -495,10 +495,12 @@
+                             unused: 0,
+                         };
+ 
+                         if fast_path {
+                             self.clip_masks.mask_instances_fast.push(instance);
++                        } else if superellipse {
++                            self.clip_masks.mask_instances_superellipse.push(instance);
+                         } else {
+                             self.clip_masks.mask_instances_slow.push(instance);
+                         }
+                     },
+                 );
+@@ -925,19 +927,26 @@
+                 if task.rounded_rect_fast_path {
+                     results.mask_instances_fast_with_scissor
+                             .entry(*target_rect)
+                             .or_insert_with(|| memory.new_vec())
+                             .push(instance);
++                } else if task.rounded_rect_superellipse {
++                    results.mask_instances_superellipse_with_scissor
++                            .entry(*target_rect)
++                            .or_insert_with(|| memory.new_vec())
++                            .push(instance);
+                 } else {
+                     results.mask_instances_slow_with_scissor
+                             .entry(*target_rect)
+                             .or_insert_with(|| memory.new_vec())
+                             .push(instance);
+                 }
+             } else {
+                 if task.rounded_rect_fast_path {
+                     results.mask_instances_fast.push(instance);
++                } else if task.rounded_rect_superellipse {
++                    results.mask_instances_superellipse.push(instance);
+                 } else {
+                     results.mask_instances_slow.push(instance);
+                 }
+             }
+         }
+diff --git a/gfx/wr/webrender/src/render_task.rs b/gfx/wr/webrender/src/render_task.rs
+--- a/gfx/wr/webrender/src/render_task.rs
++++ b/gfx/wr/webrender/src/render_task.rs
+@@ -2240,10 +2240,11 @@
+     /// Transform from the quad primitive's space to the clip's local space.
+     pub clip_transform_id: GpuTransformId,
+     pub quad_flags: QuadFlags,
+     pub needs_scissor_rect: bool,
+     pub rounded_rect_fast_path: bool,
++    pub rounded_rect_superellipse: bool,
+ }
+ 
+ /// An clip applied to a render task using the multiply blend mode on top of
+ /// the content being clipped.
+ #[derive(Debug)]
+diff --git a/gfx/wr/webrender/src/renderer/mod.rs b/gfx/wr/webrender/src/renderer/mod.rs
+--- a/gfx/wr/webrender/src/renderer/mod.rs
++++ b/gfx/wr/webrender/src/renderer/mod.rs
+@@ -2450,10 +2450,54 @@
+                 }
+ 
+                 self.device.disable_scissor();
+             }
+ 
++            if !masks.mask_instances_superellipse.is_empty() {
++                self.shaders.borrow_mut().ps_mask_superellipse().bind(
++                    &mut self.device,
++                    projection,
++                    None,
++                    &mut self.renderer_errors,
++                    &mut self.profile,
++                    &mut self.command_log,
++                );
++
++                self.draw_instanced_batch(
++                    &masks.mask_instances_superellipse,
++                    VertexArrayKind::Mask,
++                    &BatchTextures::empty(),
++                    stats,
++                );
++            }
++
++            if !masks.mask_instances_superellipse_with_scissor.is_empty() {
++                self.shaders.borrow_mut().ps_mask_superellipse().bind(
++                    &mut self.device,
++                    projection,
++                    None,
++                    &mut self.renderer_errors,
++                    &mut self.profile,
++                    &mut self.command_log,
++                );
++
++                self.device.enable_scissor();
++
++                for (scissor_rect, instances) in &masks.mask_instances_superellipse_with_scissor {
++                    self.device.set_scissor_rect(draw_target.to_framebuffer_rect(*scissor_rect));
++
++                    self.draw_instanced_batch(
++                        instances,
++                        VertexArrayKind::Mask,
++                        &BatchTextures::empty(),
++                        stats,
++                    );
++                }
++
++                self.device.disable_scissor();
++            }
++
+             if !masks.image_mask_instances.is_empty() {
+                 self.shaders.borrow_mut().ps_quad_textured().bind(
+                     &mut self.device,
+                     projection,
+                     None,
+diff --git a/gfx/wr/webrender/src/renderer/shade.rs b/gfx/wr/webrender/src/renderer/shade.rs
+--- a/gfx/wr/webrender/src/renderer/shade.rs
++++ b/gfx/wr/webrender/src/renderer/shade.rs
+@@ -65,10 +65,11 @@
+ ];
+ 
+ const DITHERING_FEATURE: &str = "DITHERING";
+ const DUAL_SOURCE_FEATURE: &str = "DUAL_SOURCE_BLENDING";
+ const FAST_PATH_FEATURE: &str = "FAST_PATH";
++const SUPERELLIPSE_FEATURE: &str = "SUPERELLIPSE";
+ 
+ pub(crate) enum ShaderKind {
+     Primitive,
+     Cache(VertexArrayKind),
+     Text,
+@@ -449,10 +450,11 @@
+     ps_quad_backdrop: ShaderHandle,
+     ps_quad_blend: ShaderHandle,
+     ps_quad_mix_blend: ShaderHandle,
+     ps_mask: ShaderHandle,
+     ps_mask_fast: ShaderHandle,
++    ps_mask_superellipse: ShaderHandle,
+     ps_clear: ShaderHandle,
+     ps_copy: ShaderHandle,
+ 
+     composite: CompositorShaders,
+ }
+@@ -514,10 +516,17 @@
+             "ps_quad_mask",
+             &[FAST_PATH_FEATURE],
+             &shader_list,
+         )?;
+ 
++        let ps_mask_superellipse = loader.create_shader(
++            ShaderKind::Cache(VertexArrayKind::Mask),
++            "ps_quad_mask",
++            &[SUPERELLIPSE_FEATURE],
++            &shader_list,
++        )?;
++
+         let mut cs_scale = Vec::new();
+         let scale_shader_num = IMAGE_BUFFER_KINDS.len();
+         // PrimitiveShader is not clonable. Use push() to initialize the vec.
+         for _ in 0 .. scale_shader_num {
+             cs_scale.push(None);
+@@ -786,10 +795,11 @@
+             ps_quad_backdrop,
+             ps_quad_blend,
+             ps_quad_mix_blend,
+             ps_mask,
+             ps_mask_fast,
++            ps_mask_superellipse,
+             ps_split_composite,
+             ps_clear,
+             ps_copy,
+             composite,
+         })
+@@ -963,10 +973,11 @@
+     pub fn ps_quad_textured(&mut self) -> &mut LazilyCompiledShader {
+         self.loader.get(self.ps_quad_textured)
+     }
+     pub fn ps_mask(&mut self) -> &mut LazilyCompiledShader { self.loader.get(self.ps_mask) }
+     pub fn ps_mask_fast(&mut self) -> &mut LazilyCompiledShader { self.loader.get(self.ps_mask_fast) }
++    pub fn ps_mask_superellipse(&mut self) -> &mut LazilyCompiledShader { self.loader.get(self.ps_mask_superellipse) }
+     pub fn ps_clear(&mut self) -> &mut LazilyCompiledShader { self.loader.get(self.ps_clear) }
+     pub fn ps_copy(&mut self) -> &mut LazilyCompiledShader { self.loader.get(self.ps_copy) }
+ 
+     pub fn deinit(self, device: &mut Device) {
+         self.loader.deinit(device);
+diff --git a/gfx/wr/webrender_build/src/shader_features.rs b/gfx/wr/webrender_build/src/shader_features.rs
+--- a/gfx/wr/webrender_build/src/shader_features.rs
++++ b/gfx/wr/webrender_build/src/shader_features.rs
+@@ -65,11 +65,11 @@
+     let mut shaders = ShaderFeatures::new();
+ 
+     // Cache shaders
+     shaders.insert("cs_blur", vec!["ALPHA_TARGET".to_string(), "COLOR_TARGET".to_string()]);
+ 
+-    shaders.insert("ps_quad_mask", vec![String::new(), "FAST_PATH".to_string()]);
++    shaders.insert("ps_quad_mask", vec![String::new(), "FAST_PATH".to_string(), "SUPERELLIPSE".to_string()]);
+ 
+     for name in &[
+         "cs_line_decoration",
+         "cs_border_segment",
+         "cs_border_solid",
+

src/external-patches/firefox/bug_2063169/D319796.patch

@@ -0,0 +1,307 @@
+diff --git a/gfx/wr/webrender/res/ps_quad_box_shadow.glsl b/gfx/wr/webrender/res/ps_quad_box_shadow.glsl
+--- a/gfx/wr/webrender/res/ps_quad_box_shadow.glsl
++++ b/gfx/wr/webrender/res/ps_quad_box_shadow.glsl
+@@ -49,22 +49,26 @@
+ flat varying highp vec4 vElemCenter_Radius_TL;
+ flat varying highp vec4 vElemCenter_Radius_TR;
+ flat varying highp vec4 vElemCenter_Radius_BR;
+ flat varying highp vec4 vElemCenter_Radius_BL;
+ 
++#ifdef WR_FEATURE_SUPERELLIPSE
+ flat varying highp vec4 vElemShape;
++#endif
+ 
+ #ifdef WR_VERTEX_SHADER
+ 
+ void pattern_vertex(PrimitiveInfo info) {
+     vec4 data0 = fetch_from_gpu_buffer_1f(info.pattern_input.x);
+     vec4 data1 = fetch_from_gpu_buffer_1f(info.pattern_input.x + 1);
+     vec4 data2 = fetch_from_gpu_buffer_1f(info.pattern_input.x + 2);
+     vec4 data3 = fetch_from_gpu_buffer_1f(info.pattern_input.x + 3);
+     vec4 data4 = fetch_from_gpu_buffer_1f(info.pattern_input.x + 4);
+     vec4 data5 = fetch_from_gpu_buffer_1f(info.pattern_input.x + 5);
++#ifdef WR_FEATURE_SUPERELLIPSE
+     vec4 data6 = fetch_from_gpu_buffer_1f(info.pattern_input.x + 6);
++#endif
+ 
+     vec2 alloc_size     = data0.xy;
+     vec2 dest_rect_size = data0.zw;
+     vec2 dest_rect_off  = data1.xy;
+     v_uv_scale_inset    = vec4(vec2(1.0) / alloc_size, data1.z, 0.0);
+@@ -84,11 +88,11 @@
+     // Map nine-patch UV=1.0 to the true content edge (uv_p0 + content_device_size)
+     // rather than the rounded atlas entry edge (info.segment.uv_rect.p1). The atlas
+     // allocation is rounded up from content_device_size, so this edge always lies
+     // inside the entry; using it keeps the mapping stable to sub-texel precision as
+     // the blur animates (bug 2002194).
+-    vec2 content_device_size = data6.xy;
++    vec2 content_device_size = data5.xy;
+     vec2 texture_size = vec2(TEX_SIZE(sColor0));
+     vec2 uv_p0 = info.segment.uv_rect.p0;
+     vec2 uv_p1 = uv_p0 + content_device_size;
+     v_uv_rect = vec4(uv_p0, uv_p1) / texture_size.xyxy;
+     v_uv_bounds = vec4(
+@@ -110,11 +114,13 @@
+     vElemCenter_Radius_TL = vec4(elem_p0 + r_tl, r_tl);
+     vElemCenter_Radius_TR = vec4(elem_p1.x - r_tr.x, elem_p0.y + r_tr.y, r_tr);
+     vElemCenter_Radius_BR = vec4(elem_p1 - r_br, r_br);
+     vElemCenter_Radius_BL = vec4(elem_p0.x + r_bl.x, elem_p1.y - r_bl.y, r_bl);
+ 
+-    vElemShape = data5;
++#ifdef WR_FEATURE_SUPERELLIPSE
++    vElemShape = data6;
++#endif
+ }
+ 
+ #endif
+ 
+ #ifdef WR_FRAGMENT_SHADER
+@@ -170,22 +176,24 @@
+     vec3 elem_plane_bl = vec3(n_bl, dot(n_bl, vec2(c_bl.x,          c_bl.y + r_bl.y)));
+ 
+     // Reconstruct the element rect bounds from the TL and BR corner data.
+     vec4 elem_bounds = vec4(c_tl - r_tl, c_br + r_br);
+ 
+-    vec4 elem_shape = vElemShape;
+-
+     float elem_dist;
++#ifdef WR_FEATURE_SUPERELLIPSE
++    vec4 elem_shape = vElemShape;
+     if (elem_shape == vec4(1.0)) {
++#endif
+         elem_dist = distance_to_rounded_rect(
+             local_pos,
+             elem_plane_tl, vec4(c_tl, inverse_radii_squared(r_tl)),
+             elem_plane_tr, vec4(c_tr, inverse_radii_squared(r_tr)),
+             elem_plane_br, vec4(c_br, inverse_radii_squared(r_br)),
+             elem_plane_bl, vec4(c_bl, inverse_radii_squared(r_bl)),
+             elem_bounds
+         );
++#ifdef WR_FEATURE_SUPERELLIPSE
+     } else {
+         elem_dist = distance_to_shaped_rect(
+             local_pos,
+             vec4(c_tl, elem_shape.x == 1.0 ? inverse_radii_squared(r_tl) : inverse_radii(r_tl)),
+             vec4(c_tr, elem_shape.y == 1.0 ? inverse_radii_squared(r_tr) : inverse_radii(r_tr)),
+@@ -194,10 +202,11 @@
+             elem_bounds,
+             elem_shape,
+             vec4(0.0)
+         );
+     }
++#endif
+ 
+     // Outset (inset=0): dist < 0 = inside element → should be clipped out → use -elem_dist.
+     // Inset (inset=1): dist < 0 = inside element → should be kept → use elem_dist.
+     float element_clip = distance_aa(aa_range, mix(-elem_dist, elem_dist, inset));
+ 
+diff --git a/gfx/wr/webrender/src/pattern/box_shadow.rs b/gfx/wr/webrender/src/pattern/box_shadow.rs
+--- a/gfx/wr/webrender/src/pattern/box_shadow.rs
++++ b/gfx/wr/webrender/src/pattern/box_shadow.rs
+@@ -41,11 +41,14 @@
+         _sub_rect: Option<DeviceRect>,
+         _offset: LayoutVector2D,
+         _ctx: &PatternBuilderContext,
+         state: &mut PatternBuilderState,
+     ) -> Pattern {
+-        let mut writer = state.frame_gpu_data.f32.write_blocks(7);
++        let superellipse = !self.element_radius.shapes_all_round();
++
++        let block_count = if superellipse { 7 } else { 6 };
++        let mut writer = state.frame_gpu_data.f32.write_blocks(block_count);
+         writer.push_one([
+             self.shadow_rect_alloc_size.width,
+             self.shadow_rect_alloc_size.height,
+             self.dest_rect_size.width,
+             self.dest_rect_size.height,
+@@ -72,26 +75,28 @@
+             self.element_radius.bottom_right.width,
+             self.element_radius.bottom_right.height,
+             self.element_radius.bottom_left.width,
+             self.element_radius.bottom_left.height,
+         ]);
+-        writer.push_one([
+-            self.element_radius.shape_top_left,
+-            self.element_radius.shape_top_right,
+-            self.element_radius.shape_bottom_right,
+-            self.element_radius.shape_bottom_left,
+-        ]);
+         writer.push_one([
+             self.content_device_size.width,
+             self.content_device_size.height,
+             0.0,
+             0.0,
+         ]);
++        if superellipse {
++            writer.push_one([
++                self.element_radius.shape_top_left,
++                self.element_radius.shape_top_right,
++                self.element_radius.shape_bottom_right,
++                self.element_radius.shape_bottom_left,
++            ]);
++        }
+         let addr = writer.finish();
+ 
+         Pattern {
+-            kind: PatternKind::BoxShadow,
++            kind: if superellipse { PatternKind::BoxShadowSuperellipse } else { PatternKind::BoxShadow },
+             shader_input: PatternShaderInput(addr.as_int(), 0),
+             texture_input: PatternTextureInput::new(self.render_task),
+             base_color: self.color,
+             is_opaque: false,
+             blend_mode: BlendMode::PremultipliedAlpha,
+diff --git a/gfx/wr/webrender/src/pattern/mod.rs b/gfx/wr/webrender/src/pattern/mod.rs
+--- a/gfx/wr/webrender/src/pattern/mod.rs
++++ b/gfx/wr/webrender/src/pattern/mod.rs
+@@ -29,36 +29,37 @@
+     Gradient = 1,
+     Repeat = 2,
+ 
+     Mask = 3,
+     BoxShadow = 4,
++    BoxShadowSuperellipse = 5,
+     // Variants of ColorOrTexture that use a non-default sampler type
+     // (samplerExternalOES / __samplerExternal2DY2YEXT / sampler2DRect). The
+     // quad shader is compiled in matching per-kind variants; see
+     // ps_quad_textured.glsl.
+-    TextureExternal = 5,
+-    TextureExternalBT709 = 6,
+-    TextureRect = 7,
++    TextureExternal = 6,
++    TextureExternalBT709 = 7,
++    TextureRect = 8,
+     // Samples up to three planes (sColor0/1/2) and converts from YUV to RGB.
+     // Like ColorOrTexture, the YUV pattern comes in sampler-type-specific
+     // variants so that the planes are sampled with the matching sColor
+     // declaration; see ps_quad_yuv.glsl. `Yuv` is the default (TEXTURE_2D).
+-    Yuv = 8,
+-    YuvTextureExternal = 9,
+-    YuvTextureExternalBT709 = 10,
+-    YuvTextureRect = 11,
++    Yuv = 9,
++    YuvTextureExternal = 10,
++    YuvTextureExternalBT709 = 11,
++    YuvTextureRect = 12,
+     // Samples a captured backdrop texture using a (bilerp) 4-corner uv quad.
+-    Backdrop = 12,
++    Backdrop = 13,
+     // Applies a filter to a sampled source texture; see ps_quad_blend.glsl.
+-    Blend = 13,
++    Blend = 14,
+     // Composites a picture over its backdrop with a software mix-blend-mode;
+     // samples two textures (backdrop + source). See ps_quad_mix_blend.glsl.
+-    MixBlend = 14,
++    MixBlend = 15,
+     // When adding patterns, don't forget to update the NUM_PATTERNS constant.
+ }
+ 
+-pub const NUM_PATTERNS: u32 = 15;
++pub const NUM_PATTERNS: u32 = 16;
+ 
+ impl PatternKind {
+     pub fn from_u32(val: u32) -> Self {
+         assert!(val < NUM_PATTERNS);
+         unsafe { std::mem::transmute(val) }
+diff --git a/gfx/wr/webrender/src/renderer/mod.rs b/gfx/wr/webrender/src/renderer/mod.rs
+--- a/gfx/wr/webrender/src/renderer/mod.rs
++++ b/gfx/wr/webrender/src/renderer/mod.rs
+@@ -251,10 +251,11 @@
+             BatchKind::Quad(PatternKind::TextureExternalBT709) => GPU_TAG_PRIMITIVE,
+             BatchKind::Quad(PatternKind::TextureRect) => GPU_TAG_PRIMITIVE,
+             BatchKind::Quad(PatternKind::Gradient) => GPU_TAG_GRADIENT,
+             BatchKind::Quad(PatternKind::Repeat) => GPU_TAG_REPEAT,
+             BatchKind::Quad(PatternKind::BoxShadow) => GPU_TAG_PRIMITIVE,
++            BatchKind::Quad(PatternKind::BoxShadowSuperellipse) => GPU_TAG_PRIMITIVE,
+             BatchKind::Quad(PatternKind::Yuv) => GPU_TAG_BRUSH_YUV_IMAGE,
+             BatchKind::Quad(PatternKind::YuvTextureExternal) => GPU_TAG_BRUSH_YUV_IMAGE,
+             BatchKind::Quad(PatternKind::YuvTextureExternalBT709) => GPU_TAG_BRUSH_YUV_IMAGE,
+             BatchKind::Quad(PatternKind::YuvTextureRect) => GPU_TAG_BRUSH_YUV_IMAGE,
+             BatchKind::Quad(PatternKind::Backdrop) => GPU_TAG_PRIMITIVE,
+diff --git a/gfx/wr/webrender/src/renderer/shade.rs b/gfx/wr/webrender/src/renderer/shade.rs
+--- a/gfx/wr/webrender/src/renderer/shade.rs
++++ b/gfx/wr/webrender/src/renderer/shade.rs
+@@ -438,10 +438,11 @@
+     ps_quad_textured_external_bt709: Option<ShaderHandle>,
+     ps_quad_textured_rect: Option<ShaderHandle>,
+     ps_quad_repeat: ShaderHandle,
+     ps_quad_gradient: ShaderHandle,
+     ps_quad_box_shadow: ShaderHandle,
++    ps_quad_box_shadow_superellipse: ShaderHandle,
+     // ps_quad_yuv, like ps_quad_textured, comes in sampler-type-specific
+     // variants so the YUV planes are sampled with the matching sColor
+     // declaration. The variant is selected via PatternKind.
+     ps_quad_yuv: ShaderHandle,
+     ps_quad_yuv_external: Option<ShaderHandle>,
+@@ -651,10 +652,17 @@
+             "ps_quad_box_shadow",
+             &[],
+             &shader_list,
+         )?;
+ 
++        let ps_quad_box_shadow_superellipse = loader.create_shader(
++            ShaderKind::Primitive,
++            "ps_quad_box_shadow",
++            &[SUPERELLIPSE_FEATURE],
++            &shader_list,
++        )?;
++
+         let ps_quad_yuv = loader.create_shader(
+             ShaderKind::Primitive,
+             "ps_quad_yuv",
+             &["TEXTURE_2D"],
+             &shader_list,
+@@ -786,10 +794,11 @@
+             ps_quad_textured_external_bt709,
+             ps_quad_textured_rect,
+             ps_quad_repeat,
+             ps_quad_gradient,
+             ps_quad_box_shadow,
++            ps_quad_box_shadow_superellipse,
+             ps_quad_yuv,
+             ps_quad_yuv_external,
+             ps_quad_yuv_external_bt709,
+             ps_quad_yuv_rect,
+             ps_quad_backdrop,
+@@ -867,10 +876,11 @@
+             PatternKind::TextureRect => self.ps_quad_textured_rect
+                 .expect("bug: ps_quad_textured TEXTURE_RECT variant not loaded"),
+             PatternKind::Gradient => self.ps_quad_gradient,
+             PatternKind::Repeat => self.ps_quad_repeat,
+             PatternKind::BoxShadow => self.ps_quad_box_shadow,
++            PatternKind::BoxShadowSuperellipse => self.ps_quad_box_shadow_superellipse,
+             PatternKind::Yuv => self.ps_quad_yuv,
+             PatternKind::YuvTextureExternal => self.ps_quad_yuv_external
+                 .expect("bug: ps_quad_yuv TEXTURE_EXTERNAL variant not loaded"),
+             PatternKind::YuvTextureExternalBT709 => self.ps_quad_yuv_external_bt709
+                 .expect("bug: ps_quad_yuv TEXTURE_EXTERNAL_BT709 variant not loaded"),
+@@ -923,10 +933,13 @@
+                 self.ps_quad_repeat
+             }
+             BatchKind::Quad(PatternKind::BoxShadow) => {
+                 self.ps_quad_box_shadow
+             }
++            BatchKind::Quad(PatternKind::BoxShadowSuperellipse) => {
++                self.ps_quad_box_shadow_superellipse
++            }
+             BatchKind::Quad(PatternKind::Yuv) => {
+                 self.ps_quad_yuv
+             }
+             BatchKind::Quad(PatternKind::YuvTextureExternal) => {
+                 self.ps_quad_yuv_external
+diff --git a/gfx/wr/webrender_build/src/shader_features.rs b/gfx/wr/webrender_build/src/shader_features.rs
+--- a/gfx/wr/webrender_build/src/shader_features.rs
++++ b/gfx/wr/webrender_build/src/shader_features.rs
+@@ -166,11 +166,11 @@
+     }
+     shaders.insert("ps_quad_textured", ps_quad_textured_features);
+ 
+     shaders.insert("ps_quad_repeat", vec![base_prim_features.finish()]);
+ 
+-    shaders.insert("ps_quad_box_shadow", vec![base_prim_features.finish()]);
++    shaders.insert("ps_quad_box_shadow", vec![base_prim_features.finish(), "SUPERELLIPSE".to_string()]);
+ 
+     // Like ps_quad_textured, ps_quad_yuv needs per-texture-kind variants so that
+     // the YUV planes are sampled with the correct sampler type.
+     let mut ps_quad_yuv_features: Vec<String> = vec!["TEXTURE_2D".to_string()];
+     if flags.contains(ShaderFeatureFlags::GL) {
+

src/external-patches/firefox/bug_2063169/D319869.patch

@@ -0,0 +1,560 @@
+diff --git a/gfx/wr/webrender/res/border_shared.glsl b/gfx/wr/webrender/res/border_shared.glsl
+--- a/gfx/wr/webrender/res/border_shared.glsl
++++ b/gfx/wr/webrender/res/border_shared.glsl
+@@ -27,25 +27,33 @@
+     vec4 rect;
+     vec4 color0;
+     vec4 color1;
+     vec2 widths;
+     vec2 radii;
++#ifdef WR_FEATURE_SUPERELLIPSE
+     float shape;
+     vec2 shape_offset;
+     vec2 inset;
++#endif
+ };
+ 
+ BorderInstanceGpuData fetch_gpu_data(int index) {
+     BorderInstanceGpuData data;
+ 
++#ifdef WR_FEATURE_SUPERELLIPSE
+     vec4 texels[6] = fetch_from_gpu_buffer_6f(index);
++#else
++    vec4 texels[4] = fetch_from_gpu_buffer_4f(index);
++#endif
+     data.rect = texels[0];
+     data.color0 = texels[1];
+     data.color1 = texels[2];
+     data.widths = texels[3].xy;
+     data.radii = texels[3].zw;
++#ifdef WR_FEATURE_SUPERELLIPSE
+     data.shape = texels[4].x;
+     data.shape_offset = texels[4].yz;
+     data.inset = texels[5].xy;
++#endif
+ 
+     return data;
+ }
+diff --git a/gfx/wr/webrender/res/cs_border_segment.glsl b/gfx/wr/webrender/res/cs_border_segment.glsl
+--- a/gfx/wr/webrender/res/cs_border_segment.glsl
++++ b/gfx/wr/webrender/res/cs_border_segment.glsl
+@@ -30,11 +30,13 @@
+ flat varying highp vec4 vClipCenter_Sign;
+ 
+ // An outer and inner elliptical radii for border
+ // corner clipping.
+ flat varying highp vec4 vClipRadii;
++#ifdef WR_FEATURE_SUPERELLIPSE
+ flat varying highp vec4 vClipOffsets;
++#endif
+ 
+ // Reference point for determine edge clip lines.
+ flat varying highp vec4 vEdgeReference;
+ 
+ // Stores widths/2 and widths/3 to save doing this in FS.
+@@ -192,26 +194,34 @@
+     vColor00 = color0[0];
+     vColor01 = color0[1];
+     vec4[2] color1 = get_colors_for_side(data.color1, style1);
+     vColor10 = color1[0];
+     vColor11 = color1[1];
++#ifdef WR_FEATURE_SUPERELLIPSE
+     vClipCenter_Sign = vec4(outer + clip_sign * (data.radii + data.shape_offset), clip_sign);
++#else
++    vClipCenter_Sign = vec4(outer + clip_sign * data.radii, clip_sign);
++#endif
+     vClipRadii = vec4(data.radii, max(data.radii - data.widths, 0.0));
++#ifdef WR_FEATURE_SUPERELLIPSE
+     vClipOffsets = vec4(0.0);
++#endif
+     vColorLine = vec4(outer, data.widths.y * -clip_sign.y, data.widths.x * clip_sign.x);
+     vEdgeReference = vec4(edge_reference, edge_reference + data.widths);
+     vClipParams1 = aClipParams1;
+     vClipParams2 = aClipParams2;
+ 
++#ifdef WR_FEATURE_SUPERELLIPSE
+     if (data.shape != 1.0)
+     {
+         vec2 reference_radii = (data.radii == vec2(0.0)) ? vec2(0.0) : data.radii + data.inset;
+         vec4 contour1 = compute_contoured_superellipse(reference_radii, data.shape, data.inset);
+         vec4 contour2 = compute_contoured_superellipse(reference_radii, data.shape, data.inset + data.widths);
+         vClipOffsets = vec4(contour1.xy, contour2.xy);
+         vClipRadii = vec4(contour1.zw, contour2.zw);
+     }
++#endif
+ 
+     // For the case of dot and dash clips, optimize the number of pixels that
+     // are hit to just include the dot itself.
+     if (clip_mode == CLIP_DOT) {
+         float radius = aClipParams1.z;
+@@ -258,19 +268,22 @@
+             // also 0.67 of the radii. Use these to form a
+             // SDF subtraction which will clip out the inside
+             // third of the rounded edge.
+             float d_radii_a;
+             float d_radii_b;
++#ifdef WR_FEATURE_SUPERELLIPSE
+             if (data.shape == 1.0) {
++#endif
+                 d_radii_a = distance_to_ellipse(
+                     clip_relative_pos,
+                     clip_radii.xy - vPartialWidths.xy
+                 );
+                 d_radii_b = distance_to_ellipse(
+                     clip_relative_pos,
+                     clip_radii.xy - 2.0 * vPartialWidths.xy
+                 );
++#ifdef WR_FEATURE_SUPERELLIPSE
+             } else {
+                 d_radii_a = distance_to_superellipse(
+                     clip_relative_pos - mix(vClipOffsets.xy, vClipOffsets.zw, 1.0 / 3.0),
+                     mix(clip_radii.xy, clip_radii.zw, 1.0 / 3.0),
+                     data.shape
+@@ -286,24 +299,28 @@
+                 d_radii_a = max(d_radii_a, -min(included_region_a.x, included_region_a.y));
+ 
+                 vec2 included_region_b = data.radii - 2.0 * vPartialWidths.xy - clip_relative_pos;
+                 d_radii_b = max(d_radii_b, -min(included_region_b.x, included_region_b.y));
+             }
++#endif
+ 
+             float d = min(-d_radii_a, d_radii_b);
+ 
+             color0 *= distance_aa(aa_range, d);
+             break;
+         }
+         case BORDER_STYLE_GROOVE:
+         case BORDER_STYLE_RIDGE: {
+             float d;
++#ifdef WR_FEATURE_SUPERELLIPSE
+             if (data.shape == 1.0) {
++#endif
+                 d = distance_to_ellipse(
+                     clip_relative_pos,
+                     clip_radii.xy - vPartialWidths.zw
+                 );
++#ifdef WR_FEATURE_SUPERELLIPSE
+             } else {
+                 d = distance_to_superellipse(
+                     clip_relative_pos - mix(vClipOffsets.xy, vClipOffsets.zw, 0.5),
+                     mix(clip_radii.xy, clip_radii.zw, 0.5),
+                     data.shape
+@@ -311,10 +328,11 @@
+ 
+                 // Clamp to the middle of the adjacent borders
+                 vec2 included_region = data.radii - vPartialWidths.zw - clip_relative_pos;
+                 d = max(d, -min(included_region.x, included_region.y));
+             }
++#endif
+             float alpha = distance_aa(aa_range, d);
+             float swizzled_factor;
+             switch (segment) {
+                 case SEGMENT_TOP_LEFT: swizzled_factor = 0.0; break;
+                 case SEGMENT_TOP_RIGHT: swizzled_factor = mix_factor; break;
+@@ -435,22 +453,26 @@
+ 
+     if (in_clip_region) {
+         float d_radii_a;
+         float d_radii_b;
+ 
++#ifdef WR_FEATURE_SUPERELLIPSE
+         if (data.shape == 1.0) {
++#endif
+             d_radii_a = distance_to_ellipse(clip_relative_pos, vClipRadii.xy);
+             d_radii_b = distance_to_ellipse(clip_relative_pos, vClipRadii.zw);
++#ifdef WR_FEATURE_SUPERELLIPSE
+         } else {
+             clip_relative_pos = abs(clip_relative_pos) - data.shape_offset;
+             d_radii_a = distance_to_superellipse(clip_relative_pos - vClipOffsets.xy, vClipRadii.xy, data.shape);
+             d_radii_b = distance_to_superellipse(clip_relative_pos - vClipOffsets.zw, vClipRadii.zw, data.shape);
+ 
+             // exclude the straight border part from the subtracted region
+             vec2 included_region = data.radii - data.widths - clip_relative_pos;
+             d_radii_b = max(d_radii_b, -min(included_region.x, included_region.y));
+         }
++#endif
+ 
+         float d_radii = max(d_radii_a, -d_radii_b);
+         d = max(d, d_radii);
+         
+         color0 = evaluate_color_for_style_in_corner(
+diff --git a/gfx/wr/webrender/res/cs_border_solid.glsl b/gfx/wr/webrender/res/cs_border_solid.glsl
+--- a/gfx/wr/webrender/res/cs_border_solid.glsl
++++ b/gfx/wr/webrender/res/cs_border_solid.glsl
+@@ -31,11 +31,13 @@
+ flat varying highp vec4 vClipCenter_Sign;
+ 
+ // An outer and inner elliptical radii for border
+ // corner clipping.
+ flat varying highp vec4 vClipRadii;
++#ifdef WR_FEATURE_SUPERELLIPSE
+ flat varying highp vec4 vClipOffsets;
++#endif
+ 
+ // Position, scale, and radii of horizontally and vertically adjacent corner clips.
+ flat varying highp vec4 vHorizontalClipCenter_Sign;
+ flat varying highp vec2 vHorizontalClipRadii;
+ flat varying highp vec4 vVerticalClipCenter_Sign;
+@@ -74,11 +76,11 @@
+ void main(void) {
+     BorderInstanceGpuData data = fetch_gpu_data(aGpuDataAddress);
+     vGpuDataAddress.x = aGpuDataAddress;
+ 
+     int segment = aFlags & 0xff;
+-    bool do_aa = ((aFlags >> 24) & 0xf0) != 0;
++    bool do_aa = ((aFlags >> 28) & 0x1) != 0;
+ 
+     vec2 outer_scale = get_outer_corner_scale(segment);
+     vec2 size = data.rect.zw - data.rect.xy;
+     vec2 outer = outer_scale * size;
+     vec2 clip_sign = 1.0 - 2.0 * outer_scale;
+@@ -100,23 +102,31 @@
+     vMixColors.x = mix_colors;
+     vPos = size * aPosition.xy;
+ 
+     vColor0 = data.color0;
+     vColor1 = data.color1;
++#ifdef WR_FEATURE_SUPERELLIPSE
+     vClipCenter_Sign = vec4(outer + clip_sign * (data.radii + data.shape_offset), clip_sign);
++#else
++    vClipCenter_Sign = vec4(outer + clip_sign * data.radii, clip_sign);
++#endif
+     vClipRadii = vec4(data.radii, max(data.radii - data.widths, 0.0));
++#ifdef WR_FEATURE_SUPERELLIPSE
+     vClipOffsets = vec4(0.0);
++#endif
+     vColorLine = vec4(outer, data.widths.y * -clip_sign.y, data.widths.x * clip_sign.x);
+ 
++#ifdef WR_FEATURE_SUPERELLIPSE
+     if (data.shape != 1.0)
+     {
+         vec2 reference_radii = (data.radii == vec2(0.0)) ? vec2(0.0) : data.radii + data.inset;
+         vec4 contour1 = compute_contoured_superellipse(reference_radii, data.shape, data.inset);
+         vec4 contour2 = compute_contoured_superellipse(reference_radii, data.shape, data.inset + data.widths);
+         vClipOffsets = vec4(contour1.xy, contour2.xy);
+         vClipRadii = vec4(contour1.zw, contour2.zw);
+     }
++#endif
+ 
+     vec2 horizontal_clip_sign = vec2(-clip_sign.x, clip_sign.y);
+     vHorizontalClipCenter_Sign = vec4(aClipParams1.xy +
+                                       horizontal_clip_sign * aClipParams1.zw,
+                                       horizontal_clip_sign);
+@@ -156,22 +166,26 @@
+     float d = -1.0;
+     if (in_clip_region) {
+         float d_radii_a;
+         float d_radii_b;
+ 
++#ifdef WR_FEATURE_SUPERELLIPSE
+         if (data.shape == 1.0) {
++#endif
+             d_radii_a = distance_to_ellipse(clip_relative_pos, vClipRadii.xy);
+             d_radii_b = distance_to_ellipse(clip_relative_pos, vClipRadii.zw);
++#ifdef WR_FEATURE_SUPERELLIPSE
+         } else {
+             clip_relative_pos = abs(clip_relative_pos) - data.shape_offset;
+             d_radii_a = distance_to_superellipse(clip_relative_pos - vClipOffsets.xy, vClipRadii.xy, data.shape);
+             d_radii_b = distance_to_superellipse(clip_relative_pos - vClipOffsets.zw, vClipRadii.zw, data.shape);
+ 
+             // exclude the straight border part from the subtracted region
+             vec2 included_region = data.radii - data.widths - clip_relative_pos;
+             d_radii_b = max(d_radii_b, -min(included_region.x, included_region.y));
+         }
++#endif
+ 
+         d = max(d_radii_a, -d_radii_b);
+     }
+ 
+     // And again for horizontally-adjacent corner
+diff --git a/gfx/wr/webrender/src/border.rs b/gfx/wr/webrender/src/border.rs
+--- a/gfx/wr/webrender/src/border.rs
++++ b/gfx/wr/webrender/src/border.rs
+@@ -855,14 +855,17 @@
+     h_adjacent_corner_radius: DeviceSize,
+     v_adjacent_corner_outer: DevicePoint,
+     v_adjacent_corner_radius: DeviceSize,
+     gpu_buffer_builder: &mut GpuBufferBuilderF,
+ ) {
++    let superellipse = shape != 1.0;
++
+     let base_flags = (segment as i32) |
+                      ((style0 as i32) << 8) |
+                      ((style1 as i32) << 16) |
+-                     ((do_aa as i32) << 28);
++                     ((do_aa as i32) << 28) |
++                     ((superellipse as i32) << 29);
+ 
+     let instance_gpu_data = BorderInstanceGpuData {
+         local_rect: task_rect,
+         color0: color0.premultiplied(),
+         color1: color1.premultiplied(),
+@@ -875,11 +878,11 @@
+ 
+     let base_instance = BorderInstance {
+         task_origin: DevicePoint::zero(),
+         flags: base_flags,
+         clip_params: [0.0; 8],
+-        gpu_data_address: instance_gpu_data.write(gpu_buffer_builder)
++        gpu_data_address: instance_gpu_data.write(superellipse, gpu_buffer_builder)
+     };
+ 
+     match segment {
+         BorderSegment::TopLeft |
+         BorderSegment::TopRight |
+diff --git a/gfx/wr/webrender/src/gpu_types.rs b/gfx/wr/webrender/src/gpu_types.rs
+--- a/gfx/wr/webrender/src/gpu_types.rs
++++ b/gfx/wr/webrender/src/gpu_types.rs
+@@ -192,18 +192,21 @@
+     pub shape_offset: DeviceSize,
+     pub inset: DeviceSize,
+ }
+ 
+ impl BorderInstanceGpuData {
+-    pub fn write(&self, gpu_buffer_builder: &mut GpuBufferBuilderF) -> GpuBufferAddress {
+-        let mut writer = gpu_buffer_builder.write_blocks(6);
++    pub fn write(&self, superellipse: bool, gpu_buffer_builder: &mut GpuBufferBuilderF) -> GpuBufferAddress {
++        let block_count = if superellipse { 6 } else { 4 };
++        let mut writer = gpu_buffer_builder.write_blocks(block_count);
+         writer.push_one(self.local_rect);
+         writer.push_one(self.color0);
+         writer.push_one(self.color1);
+         writer.push_one([self.widths.width, self.widths.height, self.radius.width, self.radius.height]);
+-        writer.push_one([self.shape, self.shape_offset.width, self.shape_offset.height, 0.0]);
+-        writer.push_one([self.inset.width, self.inset.height, 0.0, 0.0]);
++        if superellipse {
++            writer.push_one([self.shape, self.shape_offset.width, self.shape_offset.height, 0.0]);
++            writer.push_one([self.inset.width, self.inset.height, 0.0, 0.0]);
++        }
+ 
+         writer.finish()
+     }
+ }
+ 
+diff --git a/gfx/wr/webrender/src/render_target.rs b/gfx/wr/webrender/src/render_target.rs
+--- a/gfx/wr/webrender/src/render_target.rs
++++ b/gfx/wr/webrender/src/render_target.rs
+@@ -33,10 +33,11 @@
+ use crate::spatial_tree::SpatialNodeIndex;
+ 
+ 
+ const STYLE_SOLID: i32 = ((BorderStyle::Solid as i32) << 8) | ((BorderStyle::Solid as i32) << 16);
+ const STYLE_MASK: i32 = 0x00FF_FF00;
++const SUPERELLIPSE_MASK: i32 = 1 << 29;
+ 
+ /// A tag used to identify the output format of a `RenderTarget`.
+ #[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
+ #[cfg_attr(feature = "capture", derive(Serialize))]
+ #[cfg_attr(feature = "replay", derive(Deserialize))]
+@@ -163,10 +164,12 @@
+ 
+     pub clip_masks: ClipMaskInstanceList,
+ 
+     pub border_segments_complex: FrameVec<BorderInstance>,
+     pub border_segments_solid: FrameVec<BorderInstance>,
++    pub border_segments_complex_superellipse: FrameVec<BorderInstance>,
++    pub border_segments_solid_superellipse: FrameVec<BorderInstance>,
+     pub line_decorations: FrameVec<LineDecorationJob>,
+ 
+     // Clearing render targets has a fair amount of special cases.
+     // The general rules are:
+     // - Depth (for at least the used potion of the target) is always cleared if it
+@@ -223,10 +226,12 @@
+             prim_instances: std::array::from_fn(|_| FastHashMap::default()),
+             prim_instances_with_scissor: FastHashMap::default(),
+             clip_masks: ClipMaskInstanceList::new(memory),
+             border_segments_complex: memory.new_vec(),
+             border_segments_solid: memory.new_vec(),
++            border_segments_complex_superellipse: memory.new_vec(),
++            border_segments_solid_superellipse: memory.new_vec(),
+             clears: memory.new_vec(),
+             line_decorations: memory.new_vec(),
+         }
+     }
+ 
+@@ -547,14 +552,23 @@
+                 let instances = task_info.instances.clone();
+                 for mut instance in instances {
+                     // TODO(gw): It may be better to store the task origin in
+                     //           the render task data instead of per instance.
+                     instance.task_origin = task_origin;
++                    let superellipse = (instance.flags & SUPERELLIPSE_MASK) != 0;
+                     if instance.flags & STYLE_MASK == STYLE_SOLID {
+-                        self.border_segments_solid.push(instance);
++                        if superellipse {
++                            self.border_segments_solid_superellipse.push(instance);
++                        } else {
++                            self.border_segments_solid.push(instance);
++                        }
+                     } else {
+-                        self.border_segments_complex.push(instance);
++                        if superellipse {
++                            self.border_segments_complex_superellipse.push(instance);
++                        } else {
++                            self.border_segments_complex.push(instance);
++                        }
+                     }
+                 }
+             }
+             RenderTaskKind::Image(..) |
+             RenderTaskKind::Cached(..) |
+diff --git a/gfx/wr/webrender/src/renderer/mod.rs b/gfx/wr/webrender/src/renderer/mod.rs
+--- a/gfx/wr/webrender/src/renderer/mod.rs
++++ b/gfx/wr/webrender/src/renderer/mod.rs
+@@ -3394,11 +3394,13 @@
+             draw_target,
+         );
+ 
+         // Draw any borders for this target.
+         if !target.border_segments_solid.is_empty() ||
+-           !target.border_segments_complex.is_empty()
++           !target.border_segments_complex.is_empty() ||
++           !target.border_segments_solid_superellipse.is_empty() ||
++           !target.border_segments_complex_superellipse.is_empty()
+         {
+             let _timer = self.gpu_profiler.start_timer(GPU_TAG_CACHE_BORDER);
+ 
+             self.set_blend(true, FramebufferKind::Other);
+             self.set_blend_mode_premultiplied_alpha(FramebufferKind::Other);
+@@ -3437,10 +3439,46 @@
+                     &BatchTextures::empty(),
+                     stats,
+                 );
+             }
+ 
++            if !target.border_segments_solid_superellipse.is_empty() {
++                self.shaders.borrow_mut().cs_border_solid_superellipse().bind(
++                    &mut self.device,
++                    &projection,
++                    None,
++                    &mut self.renderer_errors,
++                    &mut self.profile,
++                    &mut self.command_log,
++                );
++
++                self.draw_instanced_batch(
++                    &target.border_segments_solid_superellipse,
++                    VertexArrayKind::Border,
++                    &BatchTextures::empty(),
++                    stats,
++                );
++            }
++
++            if !target.border_segments_complex_superellipse.is_empty() {
++                self.shaders.borrow_mut().cs_border_segment_superellipse().bind(
++                    &mut self.device,
++                    &projection,
++                    None,
++                    &mut self.renderer_errors,
++                    &mut self.profile,
++                    &mut self.command_log,
++                );
++
++                self.draw_instanced_batch(
++                    &target.border_segments_complex_superellipse,
++                    VertexArrayKind::Border,
++                    &BatchTextures::empty(),
++                    stats,
++                );
++            }
++
+             self.set_blend(false, FramebufferKind::Other);
+         }
+ 
+         // Draw any line decorations for this target.
+         if !target.line_decorations.is_empty() {
+diff --git a/gfx/wr/webrender/src/renderer/shade.rs b/gfx/wr/webrender/src/renderer/shade.rs
+--- a/gfx/wr/webrender/src/renderer/shade.rs
++++ b/gfx/wr/webrender/src/renderer/shade.rs
+@@ -413,10 +413,12 @@
+     // draw intermediate results to cache targets. The results
+     // of these shaders are then used by the primitive shaders.
+     cs_blur_rgba8: ShaderHandle,
+     cs_border_segment: ShaderHandle,
+     cs_border_solid: ShaderHandle,
++    cs_border_segment_superellipse: ShaderHandle,
++    cs_border_solid_superellipse: ShaderHandle,
+     cs_scale: Vec<Option<ShaderHandle>>,
+     cs_line_decoration: ShaderHandle,
+     cs_svg_filter_node: ShaderHandle,
+ 
+     // The are "primitive shaders". These shaders draw and blend
+@@ -774,19 +776,35 @@
+             "cs_border_solid",
+             &[],
+             &shader_list,
+         )?;
+ 
++        let cs_border_segment_superellipse = loader.create_shader(
++            ShaderKind::Cache(VertexArrayKind::Border),
++            "cs_border_segment",
++             &[SUPERELLIPSE_FEATURE],
++            &shader_list,
++        )?;
++
++        let cs_border_solid_superellipse = loader.create_shader(
++            ShaderKind::Cache(VertexArrayKind::Border),
++            "cs_border_solid",
++            &[SUPERELLIPSE_FEATURE],
++            &shader_list,
++        )?;
++
+         let composite = CompositorShaders::new(device, gl_type, &mut loader)?;
+ 
+         Ok(Shaders {
+             loader,
+ 
+             cs_blur_rgba8,
+             cs_border_segment,
+-            cs_line_decoration,
+             cs_border_solid,
++            cs_border_segment_superellipse,
++            cs_border_solid_superellipse,
++            cs_line_decoration,
+             cs_scale,
+             cs_svg_filter_node,
+             ps_text_run,
+             ps_text_run_dual_source,
+             ps_quad_textured,
+@@ -979,10 +997,12 @@
+     }
+ 
+     pub fn cs_blur_rgba8(&mut self) -> &mut LazilyCompiledShader { self.loader.get(self.cs_blur_rgba8) }
+     pub fn cs_border_segment(&mut self) -> &mut LazilyCompiledShader { self.loader.get(self.cs_border_segment) }
+     pub fn cs_border_solid(&mut self) -> &mut LazilyCompiledShader { self.loader.get(self.cs_border_solid) }
++    pub fn cs_border_segment_superellipse(&mut self) -> &mut LazilyCompiledShader { self.loader.get(self.cs_border_segment_superellipse) }
++    pub fn cs_border_solid_superellipse(&mut self) -> &mut LazilyCompiledShader { self.loader.get(self.cs_border_solid_superellipse) }
+     pub fn cs_line_decoration(&mut self) -> &mut LazilyCompiledShader { self.loader.get(self.cs_line_decoration) }
+     pub fn cs_svg_filter_node(&mut self) -> &mut LazilyCompiledShader { self.loader.get(self.cs_svg_filter_node) }
+     pub fn ps_quad_textured(&mut self) -> &mut LazilyCompiledShader {
+         self.loader.get(self.ps_quad_textured)
+     }
+diff --git a/gfx/wr/webrender_build/src/shader_features.rs b/gfx/wr/webrender_build/src/shader_features.rs
+--- a/gfx/wr/webrender_build/src/shader_features.rs
++++ b/gfx/wr/webrender_build/src/shader_features.rs
+@@ -69,17 +69,22 @@
+ 
+     shaders.insert("ps_quad_mask", vec![String::new(), "FAST_PATH".to_string(), "SUPERELLIPSE".to_string()]);
+ 
+     for name in &[
+         "cs_line_decoration",
+-        "cs_border_segment",
+-        "cs_border_solid",
+         "cs_svg_filter_node",
+     ] {
+         shaders.insert(name, vec![String::new()]);
+     }
+ 
++    for name in &[
++        "cs_border_segment",
++        "cs_border_solid",
++    ] {
++        shaders.insert(name, vec![String::new(), "SUPERELLIPSE".to_string()]);
++    }
++
+     let mut base_prim_features = FeatureList::new();
+ 
+     let mut texture_types = vec!["TEXTURE_2D"];
+     if flags.contains(ShaderFeatureFlags::GL) {
+         texture_types.push("TEXTURE_RECT");
+

src/external-patches/firefox/bug_2063169/D320211.patch

@@ -0,0 +1,15 @@
+diff --git a/devtools/client/responsive/test/browser/browser.toml b/devtools/client/responsive/test/browser/browser.toml
+--- a/devtools/client/responsive/test/browser/browser.toml
++++ b/devtools/client/responsive/test/browser/browser.toml
+@@ -275,7 +275,10 @@
+ skip-if = [
+   "os == 'win' && os_version == '11.26100' && arch == 'x86_64' && asan", # Bug 2016837
+ ]
+ 
+ ["browser_window_sizing.js"]
++skip-if = [
++  "os == 'win' && opt && standalone", # Bug 2063169
++]
+ 
+ ["browser_zoom.js"]
+

src/external-patches/firefox/bug_2063169/D320568.patch

@@ -0,0 +1,34 @@
+diff --git a/layout/painting/nsDisplayList.cpp b/layout/painting/nsDisplayList.cpp
+--- a/layout/painting/nsDisplayList.cpp
++++ b/layout/painting/nsDisplayList.cpp
+@@ -4606,12 +4606,12 @@
+     wr::LayoutRect deviceClipRect = wr::ToLayoutRect(clipRect);
+ 
+     nscoord spread = shadow.spread.ToAppUnits();
+     float spreadRadius = float(spread) / float(appUnitsPerDevPixel);
+ 
+-    wr::BorderRadius borderRadius{};
+-    wr::BorderRadius shadowRadius{};
++    wr::BorderRadius borderRadius = wr::EmptyBorderRadius();
++    wr::BorderRadius shadowRadius = wr::EmptyBorderRadius();
+     if (hasBorderRadius) {
+       borderRadius = wr::ToBorderRadius(borderRadii);
+       if (spreadRadius) {
+         auto shadowRadii = borderRadii;
+         shadowRadii.AdjustOutwards(
+@@ -4727,12 +4727,12 @@
+         float(shadow.base.blur.ToAppUnits()) / float(appUnitsPerDevPixel);
+ 
+     nscoord spread = shadow.spread.ToAppUnits();
+     float spreadRadius = spread / float(appUnitsPerDevPixel);
+ 
+-    wr::BorderRadius borderRadius{};
+-    wr::BorderRadius shadowRadius{};
++    wr::BorderRadius borderRadius = wr::EmptyBorderRadius();
++    wr::BorderRadius shadowRadius = wr::EmptyBorderRadius();
+     if (hasBorderRadius) {
+       borderRadius = wr::ToBorderRadius(innerRadii);
+       if (spreadRadius) {
+         RectCornerRadii shadowRadii = innerRadii;
+         shadowRadii.AdjustInwards(
+

src/external-patches/firefox/bug_2063169/D321282.patch

@@ -0,0 +1,53 @@
+diff --git a/gfx/wr/webrender/res/ps_quad_mask.glsl b/gfx/wr/webrender/res/ps_quad_mask.glsl
+--- a/gfx/wr/webrender/res/ps_quad_mask.glsl
++++ b/gfx/wr/webrender/res/ps_quad_mask.glsl
+@@ -318,12 +318,30 @@
+     #endif
+ 
+     vec4 clip_dist =
+         mix(clip_rect, clip_rect.zwxy, lessThan(local_step, vec2(0.0)).xyxy)
+             - local_pos0.xyxy;
++
++    // Half-width, in local units, of the band around an edge over which
++    // distance_aa() produces partial coverage.
++    float aa_band = 0.5 * recip(aa_range);
++    // An axis the span does not step along has the same distance to its two
++    // edges for every pixel of the span, so the inside/outside test below
++    // cannot resolve an edge that runs parallel to the span and coverage ends
++    // up quantized to whole spans. Grow the rect by the AA band so that a span
++    // landing inside the band counts as inside, which leaves the corner
++    // selection below unchanged, and remember that the span is only partially
++    // covered so the opaque run can be dropped further down.
++    // `inset` is the distance from the span to the nearer of an axis' two
++    // edges, positive when the span is between them.
++    vec2 inset = min(-clip_dist.xy, clip_dist.zw);
++    bvec2 flat_axis = equal(local_step, vec2(0.0));
++    bvec2 partial = lessThan(inset, vec2(aa_band));
++    bool aa_span = (flat_axis.x && partial.x) || (flat_axis.y && partial.y);
++
+     clip_dist =
+-        mix(1.0e6 * step(0.0, clip_dist),
++        mix(1.0e6 * step(0.0, clip_dist - vec4(aa_band, aa_band, -aa_band, -aa_band)),
+             clip_dist * recip(local_step).xyxy,
+             notEqual(local_step, vec2(0.0)).xyxy);
+ 
+     float opaque_start = max(clip_dist.x, clip_dist.y);
+     float opaque_end = min(clip_dist.z, clip_dist.w);
+@@ -404,10 +422,16 @@
+ 
+     aa_margin = max(aa_margin - max(aa_start - aa_end, 0.0), 0.0);
+     aa_start -= aa_margin;
+     aa_end += aa_margin;
+ 
++    if (aa_span) {
++        // No pixel of the span is fully covered, so collapse the opaque run and
++        // let the anti-aliased runs on either side of it cover the whole span.
++        opaque_end = min(opaque_end, opaque_start);
++    }
++
+     ivec4 steps = ivec4(clamp(
+         swgl_SpanLength -
+             swgl_StepSize *
+                 vec4(floor(aa_start), ceil(opaque_start), floor(opaque_end), ceil(aa_end)),
+         0.0, swgl_SpanLength));
+

src/external-patches/firefox/issue_15123.patch

@@ -0,0 +1,154 @@
+diff --git a/toolkit/modules/subprocess/subprocess_shared_unix.js b/toolkit/modules/subprocess/subprocess_shared_unix.js
+--- a/toolkit/modules/subprocess/subprocess_shared_unix.js
++++ b/toolkit/modules/subprocess/subprocess_shared_unix.js
+@@ -52,16 +52,17 @@
+ 
+   close: [ctypes.default_abi, ctypes.int, ctypes.int /* fildes */],
+ 
+   dup: [ctypes.default_abi, ctypes.int, ctypes.int],
+ 
++  // Variadic arguments use a different calling convention on Apple silicon.
+   fcntl: [
+     ctypes.default_abi,
+     ctypes.int,
+     ctypes.int /* fildes */,
+     ctypes.int /* cmd */,
+-    ctypes.int /* ... */,
++    "...",
+   ],
+ 
+   getcwd: [
+     ctypes.default_abi,
+     ctypes.char.ptr,
+diff --git a/toolkit/modules/subprocess/subprocess_unix.sys.mjs b/toolkit/modules/subprocess/subprocess_unix.sys.mjs
+--- a/toolkit/modules/subprocess/subprocess_unix.sys.mjs
++++ b/toolkit/modules/subprocess/subprocess_unix.sys.mjs
+@@ -34,13 +34,13 @@
+       throw new Error("Unable to create pipe");
+     }
+ 
+     this.signalFd = fds[1];
+ 
+-    libc.fcntl(fds[0], LIBC.F_SETFL, LIBC.O_NONBLOCK);
+-    libc.fcntl(fds[0], LIBC.F_SETFD, LIBC.FD_CLOEXEC);
+-    libc.fcntl(fds[1], LIBC.F_SETFD, LIBC.FD_CLOEXEC);
++    libc.fcntl(fds[0], LIBC.F_SETFL, ctypes.int(LIBC.O_NONBLOCK));
++    libc.fcntl(fds[0], LIBC.F_SETFD, ctypes.int(LIBC.FD_CLOEXEC));
++    libc.fcntl(fds[1], LIBC.F_SETFD, ctypes.int(LIBC.FD_CLOEXEC));
+ 
+     this.call("init", [{ signalFd: fds[0] }]);
+   }
+ 
+   closePipe() {
+diff --git a/toolkit/modules/subprocess/subprocess_unix.worker.js b/toolkit/modules/subprocess/subprocess_unix.worker.js
+--- a/toolkit/modules/subprocess/subprocess_unix.worker.js
++++ b/toolkit/modules/subprocess/subprocess_unix.worker.js
+@@ -349,13 +349,13 @@
+         our_pipes.push(new InputPipe(this, fds[1]));
+       } else {
+         our_pipes.push(new OutputPipe(this, fds[1]));
+       }
+ 
+-      libc.fcntl(fds[0], LIBC.F_SETFD, LIBC.FD_CLOEXEC);
+-      libc.fcntl(fds[1], LIBC.F_SETFD, LIBC.FD_CLOEXEC);
+-      libc.fcntl(fds[1], LIBC.F_SETFL, LIBC.O_NONBLOCK);
++      libc.fcntl(fds[0], LIBC.F_SETFD, ctypes.int(LIBC.FD_CLOEXEC));
++      libc.fcntl(fds[1], LIBC.F_SETFD, ctypes.int(LIBC.FD_CLOEXEC));
++      libc.fcntl(fds[1], LIBC.F_SETFL, ctypes.int(LIBC.O_NONBLOCK));
+ 
+       return fds[0];
+     };
+ 
+     their_pipes.set(0, pipe(false));
+diff --git a/toolkit/modules/subprocess/test/xpcshell/test_subprocess_pipe_flags.js b/toolkit/modules/subprocess/test/xpcshell/test_subprocess_pipe_flags.js
+new file mode 100644
+--- /dev/null
++++ b/toolkit/modules/subprocess/test/xpcshell/test_subprocess_pipe_flags.js
+@@ -0,0 +1,73 @@
++/* 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/. */
++
++"use strict";
++
++add_task(async function test_subprocess_pipe_flags() {
++  const { Subprocess, getSubprocessImplForTest } = ChromeUtils.importESModule(
++    "resource://gre/modules/Subprocess.sys.mjs"
++  );
++  const { ctypes } = ChromeUtils.importESModule(
++    "resource://gre/modules/ctypes.sys.mjs"
++  );
++  const constants = ChromeUtils.getLibcConstants();
++  const library = ctypes.open("a.out");
++  const fcntl = library.declare(
++    "fcntl",
++    ctypes.default_abi,
++    ctypes.int,
++    ctypes.int,
++    ctypes.int,
++    "..."
++  );
++  // Darwin's fcntl commands for reading descriptor and file status flags.
++  const F_GETFD = 1;
++  const F_GETFL = 3;
++  let process;
++
++  try {
++    const worker = getSubprocessImplForTest().Process.getWorker();
++    Assert.equal(
++      fcntl(worker.signalFd, F_GETFD),
++      constants.FD_CLOEXEC,
++      "The main-thread signal pipe has exactly FD_CLOEXEC set"
++    );
++
++    process = await Subprocess.call({
++      command: "/bin/cat",
++      stderr: "pipe",
++      disclaim: true,
++    });
++    const fds = await worker.call("getFds", [process.id]);
++    // Only inspect the descriptors while the worker owns them and cat is alive.
++    // Exact flags also rule out an unintended FD_CLOFORK on macOS.
++    for (const fd of fds) {
++      Assert.equal(
++        fcntl(fd, F_GETFD),
++        constants.FD_CLOEXEC,
++        "Worker pipes have exactly FD_CLOEXEC set"
++      );
++      Assert.equal(
++        fcntl(fd, F_GETFL) & constants.O_NONBLOCK,
++        constants.O_NONBLOCK,
++        "Worker pipes are nonblocking"
++      );
++    }
++
++    const output = process.stdout.readString(5);
++    await process.stdin.write("hello");
++    Assert.equal(await output, "hello", "The subprocess pipes transfer data");
++    await process.stdin.close();
++    Assert.equal(
++      (await process.wait()).exitCode,
++      0,
++      "The subprocess exits cleanly"
++    );
++  } finally {
++    if (process && process.exitCode === null) {
++      await process.kill();
++    }
++    library.close();
++  }
++});
+diff --git a/toolkit/modules/subprocess/test/xpcshell/xpcshell.toml b/toolkit/modules/subprocess/test/xpcshell/xpcshell.toml
+--- a/toolkit/modules/subprocess/test/xpcshell/xpcshell.toml
++++ b/toolkit/modules/subprocess/test/xpcshell/xpcshell.toml
+@@ -25,6 +25,9 @@
+ ["test_subprocess_pathSearch.js"]
+ 
+ ["test_subprocess_perf.js"]
+ requesttimeoutfactor = 2  # Slow on Windows
+ 
++["test_subprocess_pipe_flags.js"]
++run-if = ["os == 'mac'"]
++
+ ["test_subprocess_polling.js"]
+

src/external-patches/manifest.json

@@ -7,6 +7,11 @@
     "id": "D299584",
     "name": "Native MacOS popovers fix"
   },
+  {
+    "type": "phabricator",
+    "id": "D323933",
+    "name": "Issue 15123"
+  },
   {
     "type": "local",
     // TODO: Convert into https://phabricator.services.mozilla.com/D298079
@@ -53,7 +58,14 @@
   },
   {
     "type": "local",
-    "path": "firefox/css_corner_shape_rendering.patch"
+    // Sorts before bug_2063169/ on purpose: D319869 builds on the border
+    // shader hunks in here, and surfer applies patches in path order.
+    "path": "firefox/bug_2047627_corner_shape_borders.patch"
+  },
+  {
+    "type": "phabricator",
+    "ids": ["D319577", "D319796", "D319869", "D320211", "D320568", "D321282"],
+    "name": "Bug 2063169"
   },
   {
     "type": "local",

src/zen/boosts/ZenBoostsEditor.mjs

@@ -1521,7 +1521,7 @@ ${cssSelector} {
   shuffleBoost() {
     const availFonts = this.fetchFontList();
     const commonFonts = this.commonFonts;
-    let font = commonFonts[Math.round(Math.random() * commonFonts.length)];
+    let font = commonFonts[Math.floor(Math.random() * commonFonts.length)];
     if (availFonts.includes(font)) {
       this.currentBoostData.fontFamily = font;
     }

src/zen/boosts/ZenBoostsManager.sys.mjs

@@ -649,9 +649,10 @@ class nsZenBoostsManager {
     );
 
     // Close the editor if the tab is switched
+    const onTabSelect = editor.close.bind(editor);
     parentWindow.gBrowser.tabContainer.addEventListener(
       "TabSelect",
-      editor.close.bind(editor),
+      onTabSelect,
       {
         once: true,
       }
@@ -661,13 +662,24 @@ class nsZenBoostsManager {
       onLocationChange: webProgress => {
         if (webProgress.isTopLevel) {
           editor.close();
-          parentWindow.gBrowser.removeTabsProgressListener(progressListener);
         }
       },
     };
 
     parentWindow.gBrowser.addProgressListener(progressListener);
 
+    editor.addEventListener(
+      "unload",
+      () => {
+        parentWindow.gBrowser.tabContainer.removeEventListener(
+          "TabSelect",
+          onTabSelect
+        );
+        parentWindow.gBrowser.removeProgressListener(progressListener);
+      },
+      { once: true }
+    );
+
     // Give the domain
     editor.domain = domain;
     editor.openerWindow = parentWindow;

src/zen/boosts/actors/ZenBoostsChild.sys.mjs

@@ -70,8 +70,10 @@ export class ZenBoostsChild extends JSWindowActorChild {
 
   static PREVENTABLE_SET = new Set(ZenBoostsChild.PREVENTABLE_EVENTS);
 
-  actorCreated() {
-    this.#applyBoostForPageIfAvailable();
+  handleEvent(event) {
+    if (event.type === "DOMDocElementInserted") {
+      this.#applyBoostForPageIfAvailable();
+    }
   }
 
   didDestroy() {
@@ -330,6 +332,22 @@ export class ZenBoostsChild extends JSWindowActorChild {
     return this.sendQuery("ZenBoost:GetBoostForDomain", domain);
   }
 
+  /**
+   * Sets a synced BrowsingContext field only when its value changes. Every
+   * setter commits a transaction that is broadcast to the whole browsing
+   * context group, even when the value is unchanged, so this avoids three
+   * such broadcasts on every page load that has no boost.
+   *
+   * @param {BrowsingContext} browsingContext
+   * @param {string} field - The synced field name.
+   * @param {number | boolean} value
+   */
+  #setSyncedField(browsingContext, field, value) {
+    if (browsingContext[field] !== value) {
+      browsingContext[field] = value;
+    }
+  }
+
   /**
    * Applies the boost settings for the current page if available.
    *
@@ -360,7 +378,11 @@ export class ZenBoostsChild extends JSWindowActorChild {
         sizeOverride: boostData.sizeOverride,
       });
 
-      browsingContext.isZenBoostsInverted = boostData.smartInvert;
+      this.#setSyncedField(
+        browsingContext,
+        "isZenBoostsInverted",
+        !!boostData.smartInvert
+      );
       if (boostData.enableColorBoost) {
         let primaryColor;
         if (boostData.autoTheme) {
@@ -396,18 +418,21 @@ export class ZenBoostsChild extends JSWindowActorChild {
             boostData
           );
         }
-        browsingContext.zenBoostsData = primaryColor;
+        this.#setSyncedField(browsingContext, "zenBoostsData", primaryColor);
         // The complementary accent is derived in the backend by rotating the
         // primary accent's hue by this delta (in degrees).
-        browsingContext.zenBoostsComplementaryRotation =
-          boostData.secondaryDotAngleDegDelta ?? 0;
+        this.#setSyncedField(
+          browsingContext,
+          "zenBoostsComplementaryRotation",
+          boostData.secondaryDotAngleDegDelta ?? 0
+        );
         return;
       }
     } else {
-      browsingContext.isZenBoostsInverted = false;
+      this.#setSyncedField(browsingContext, "isZenBoostsInverted", false);
     }
-    browsingContext.zenBoostsData = 0;
-    browsingContext.zenBoostsComplementaryRotation = 0;
+    this.#setSyncedField(browsingContext, "zenBoostsData", 0);
+    this.#setSyncedField(browsingContext, "zenBoostsComplementaryRotation", 0);
   }
 
   /**

src/zen/common/ZenPreloadedScripts.js

@@ -28,6 +28,7 @@
     "chrome://browser/content/zen-components/ZenEmojiPicker.mjs",
     "chrome://browser/content/zen-components/ZenLiveFoldersUI.mjs",
     "chrome://browser/content/zen-components/ZenDownloadAnimation.mjs",
+    "resource:///modules/zen/share/ZenShareManager.mjs",
   ];
 
   for (let script of scripts) {

src/zen/common/modules/ZenUIManager.mjs

@@ -257,7 +257,7 @@ window.gZenUIManager = {
     };
   },
 
-  updateTabsToolbar() {
+  updateTabsToolbar(fromResizeEvent = false) {
     const kUrlbarHeight = 333;
     gURLBar.style.setProperty(
       "--zen-urlbar-top",
@@ -270,8 +270,8 @@ window.gZenUIManager = {
     gZenVerticalTabsManager.actualWindowButtons.removeAttribute(
       "zen-has-hover"
     );
-    gZenVerticalTabsManager.recalculateURLBarHeight(true);
-    if (!this._preventToolbarRebuild) {
+    gZenVerticalTabsManager.recalculateURLBarHeight(!fromResizeEvent);
+    if (!this._preventToolbarRebuild && !fromResizeEvent) {
       setTimeout(() => {
         gZenWorkspaces.updateTabsContainers();
       }, 0);
@@ -1278,8 +1278,16 @@ window.gZenVerticalTabsManager = {
     if (gZenWorkspaces._processingResize) {
       return;
     }
+    this._pendingUrlbarFormatUpdate ||= updateFormat;
+    if (this._urlbarHeightRecalcScheduled) {
+      return;
+    }
+    this._urlbarHeightRecalcScheduled = true;
     requestAnimationFrame(() => {
       requestAnimationFrame(() => {
+        delete this._urlbarHeightRecalcScheduled;
+        const shouldUpdateFormat = this._pendingUrlbarFormatUpdate;
+        delete this._pendingUrlbarFormatUpdate;
         gURLBar.removeAttribute("--urlbar-height");
         let height;
         if (!this._hasSetSingleToolbar) {
@@ -1290,7 +1298,7 @@ window.gZenVerticalTabsManager = {
         if (typeof height !== "undefined") {
           gURLBar.style.setProperty("--urlbar-height", `${height}px`);
         }
-        if (updateFormat) {
+        if (shouldUpdateFormat) {
           gURLBar.zenFormatURLValue();
         }
       });

src/zen/common/styles/squircle-exclusions.inc.css

@@ -0,0 +1,33 @@
+/*
+ * 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/.
+ */
+
+/* Upstream elements that take their radius from --border-radius-circle (9999px).
+   They are meant to read as circles or pills, so a superellipse only makes them
+   look lumpy. */
+.tab-icon-overlay:not([crashed]):is([soundplaying], [muted], [activemedia-blocked]),
+.tab-note-icon-overlay,
+.tab-group-overflow-count,
+.tab-group-editor-swatch,
+.tab-preview-container-indicator,
+#tabbrowser-tabs[orient='vertical']:not([expanded]) .tab-close-button,
+.all-tabs-item > toolbarbutton.all-tabs-container-indicator::before,
+.urlbarView-button,
+.downloadButton,
+.titlebar-button,
+.titlebar-button .toolbarbutton-icon,
+#downloads-indicator-progress-inner,
+#smartwindow-ask-button-inner,
+#PanelUI-fxa-menu-manage-account-button,
+.fxa-menu-manage-account-avatar,
+[fxastatus='signedin'] #fxa-avatar-image,
+#profile-icon-image,
+.appMenu-update-banner-pulse-ring,
+:is(#appMenu-zoomReduce-button2, #appMenu-zoomEnlarge-button2) > .toolbarbutton-icon,
+.color-swatches .userContext-icon,
+.reusable-relay-masks > button,
+.radio-check {
+  corner-shape: round;
+}

src/zen/common/styles/zen-browser-container.css

@@ -5,11 +5,17 @@
  */
 :root:not([inDOMFullscreen="true"]):not([chromehidden~="location"]):not([chromehidden~="toolbar"]) {
   & #tabbrowser-tabbox #tabbrowser-tabpanels .browserSidebarContainer {
+    --zen-transparent-browser-background: light-dark(rgba(255, 255, 255, 0.6), rgba(255, 255, 255, 0.1));
     overflow: clip;
 
     :root:not([zen-no-padding="true"]) &:not(.zen-glance-overlay) {
       border-radius: var(--zen-native-inner-radius);
       box-shadow: var(--zen-big-shadow);
+      @media not (-moz-pref("zen.theme.squircle-browser-view")) {
+        /* stylelint-disable-next-line property-no-unknown */
+        corner-shape: round;
+        border-radius: calc(var(--zen-native-inner-radius) / var(--zen-squircle-value));
+      }
     }
 
     & browser[type="content"] {
@@ -18,7 +24,7 @@
       }
 
       &[transparent="true"] {
-        background: light-dark(rgba(255, 255, 255, 0.6), rgba(255, 255, 255, 0.1));
+        background: var(--zen-transparent-browser-background);
       }
     }
 

src/zen/common/styles/zen-buttons.css

@@ -78,3 +78,52 @@ dialog::part(dialog-button) {
     scale: 0.98;
   }
 }
+
+:root {
+  --zen-accent-button-color: light-dark(
+    oklch(from var(--zen-primary-color) clamp(0.35, l, 0.6) c h),
+    oklch(from var(--zen-primary-color) clamp(0.7, l, 0.85) c h)
+  );
+  --zen-accent-button-background: light-dark(
+    oklch(from var(--zen-primary-color) clamp(0.35, l, 0.6) c h),
+    oklch(from var(--zen-primary-color) clamp(0.55, l, 0.7) c h)
+  );
+}
+
+.zen-big-accent-button {
+  appearance: none;
+  border: none;
+  border-radius: 12px;
+  padding: 1.2rem 1rem;
+  background: transparent;
+  color: var(--zen-accent-button-color);
+  font: inherit;
+  font-size: 1.2rem;
+  font-weight: 600;
+  cursor: pointer;
+  will-change: transform;
+  transition: scale 0.15s ease-out;
+
+  &:hover {
+    scale: 1.03;
+    filter: brightness(1.1);
+  }
+
+  &:active:hover {
+    scale: 1;
+    color: color-mix(in srgb, var(--zen-accent-button-color) 80%, transparent);
+  }
+
+  &.primary {
+    background: var(--zen-accent-button-background);
+    color: white;
+
+    &:hover {
+      filter: brightness(1.1);
+    }
+
+    &:active:hover {
+      color: rgba(255, 255, 255, 0.8);
+    }
+  }
+}

src/zen/common/styles/zen-panel-ui.css

@@ -30,6 +30,13 @@ panel[type="arrow"]:not(#feature-callout) {
     }
   }
 
+  @media (-moz-platform: linux) or ((-moz-platform: windows) and (not (-moz-windows-mica-popups))) {
+    &::part(content) {
+      corner-shape: round; 
+      border-radius: calc(var(--panel-border-radius) / var(--zen-squircle-value));
+    }
+  }
+
   @media (-moz-platform: macos) {
     &:is([nonnative], :not([type="arrow"])) {
       appearance: auto !important;

src/zen/common/styles/zen-panels/bookmarks.css

@@ -64,6 +64,10 @@ hbox.editBMPanel_folderRow {
   margin-right: 10px;
 }
 
+#editBMPanel_workspaceSummary .workspace-trigger {
+  margin-inline-end: 16px;
+}
+
 /* Bookmarks in toolbar */
 #PersonalToolbar {
   background: transparent;

src/zen/common/styles/zen-theme.css

@@ -101,7 +101,7 @@
   ) !important;
   --focus-outline-color: var(--color-accent-primary) !important;
 
-  --toolbarbutton-icon-fill-attention: var(--toolbar-color) !important;
+  --toolbarbutton-icon-fill-attention: var(--toolbar-color, currentColor) !important;
   --toolbarbutton-icon-fill: currentColor !important;
 
   --button-background-color-primary: var(--in-content-primary-button-background) !important;
@@ -220,7 +220,7 @@
   --zen-squircle-value: 1.3;
 
   @media (-moz-platform: windows) {
-    --zen-squircle-value: 2.1;
+    --zen-squircle-value: 2.3;
   }
 
   --tab-icon-overlay-stroke: light-dark(white, black) !important;
@@ -361,4 +361,6 @@
   .zen-squircle-after::after {
     corner-shape: superellipse(var(--zen-squircle-value));
   }
+
+%include squircle-exclusions.inc.css
 }

src/zen/common/sys/ZenActorsManager.sys.mjs

@@ -42,7 +42,6 @@ let JSWINDOWACTORS = {
     child: {
       esModuleURI: "resource:///actors/ZenGlanceChild.sys.mjs",
       events: {
-        DOMContentLoaded: {},
         mousedown: {
           capture: true,
         },
@@ -86,9 +85,7 @@ if (!Services.appinfo.inSafeMode) {
     child: {
       esModuleURI: "resource:///actors/ZenBoostsChild.sys.mjs",
       events: {
-        // Needed to let the actor be created, please don't remove
-        // without checking if boosts still work without it, thanks <3
-        DOMWindowCreated: {},
+        DOMDocElementInserted: {},
       },
     },
     safeForUntrustedWebProcess: true,

src/zen/common/sys/ZenUIMigration.sys.mjs

@@ -12,7 +12,7 @@ ChromeUtils.defineESModuleGetters(lazy, {
 
 class nsZenUIMigration {
   PREF_NAME = "zen.ui.migration.version";
-  MIGRATION_VERSION = 7;
+  MIGRATION_VERSION = 8;
 
   init(isNewProfile) {
     if (!isNewProfile) {
@@ -164,6 +164,18 @@ class nsZenUIMigration {
       Services.prefs.setBoolPref("zen.widget.macos.window-vibrancy", false);
     }
   }
+
+  _migrateV8() {
+    // A version mismatch in the downloadable gfx blocklist wrongly blocked
+    // video overlays for every Windows user. The status pref persists in the
+    // profile and short-circuits the blocklist evaluation, so clear it (and
+    // its failure id) and restart, since gfx is already initialized by now.
+    if (Services.prefs.prefHasUserValue("gfx.blacklist.video-overlay")) {
+      Services.prefs.clearUserPref("gfx.blacklist.video-overlay");
+      Services.prefs.clearUserPref("gfx.blacklist.video-overlay.failureid");
+      this.shouldRestart = true;
+    }
+  }
 }
 
 export var gZenUIMigration = new nsZenUIMigration();

src/zen/common/zen-sets.js

@@ -41,6 +41,9 @@ document.addEventListener(
           case "cmd_zenSplitViewContextMenu":
             gZenViewSplitter.contextSplitTabs();
             break;
+          case "cmd_zenCtxShareSplitView":
+            gZenViewSplitter.contextShareSplitView();
+            break;
           case "cmd_zenCopyCurrentURLMarkdown":
             gZenCommonActions.copyCurrentURLAsMarkdownToClipboard();
             break;
@@ -90,6 +93,9 @@ document.addEventListener(
           case "cmd_zenCtxDeleteWorkspace":
             gZenWorkspaces.contextDeleteWorkspace(event);
             break;
+          case "cmd_zenCtxShareWorkspace":
+            gZenWorkspaces.contextShareWorkspace();
+            break;
           case "cmd_zenChangeWorkspaceName":
             gZenVerticalTabsManager.renameTabStart({
               target: gZenWorkspaces.activeWorkspaceIndicator.querySelector(

src/zen/common/zenThemeModifier.js

@@ -125,7 +125,7 @@
           // Windows defaults to 8px
           document.documentElement.style.setProperty(
             "--zen-border-radius",
-            "8px"
+            "9px"
           );
         }
       } else {

src/zen/compact-mode/ZenCompactMode.mjs

@@ -477,9 +477,9 @@ window.gZenCompactModeManager = {
     document.documentElement.setAttribute("zen-compact-animating", "true");
     return new Promise(resolve => {
       // We need to set the splitter width before hiding it
-      let splitterWidth = document
-        .getElementById("zen-sidebar-splitter")
-        .getBoundingClientRect().width;
+      let splitterWidth = window.windowUtils.getBoundsWithoutFlushing(
+        document.getElementById("zen-sidebar-splitter")
+      ).width;
       const isCompactMode = this.preference;
       const canHideSidebar = this.canHideSidebar;
       let canAnimate =

src/zen/compact-mode/sidebar.inc.css

@@ -52,7 +52,7 @@
     --zen-compact-float: var(--zen-element-separation);
 
     @media (-moz-mac-tahoe-theme) {
-      --zen-compact-mode-no-padding-radius-fix: -2px;
+      --zen-compact-mode-no-padding-radius-fix: -4px;
     }
 
     :root[zen-no-padding='true'] & {

src/zen/compact-mode/zen-compact-mode.css

@@ -29,7 +29,7 @@
   &,
   &::before,
   &::after {
-    border-radius: calc((var(--zen-native-inner-radius) - var(--zen-compact-mode-no-padding-radius-fix, 0px)) * var(--zen-squircle-value));
+    border-radius: calc((var(--zen-native-inner-radius) - var(--zen-compact-mode-no-padding-radius-fix, 0px)));
   }
 }
 

src/zen/drag-and-drop/ZenDragAndDrop.js

@@ -1334,10 +1334,14 @@
         dropElement = dragData.dropElement;
         dropBefore = dragData.dropBefore;
       }
-      // Essentials should be properly handled by ::animateVerticalPinnedGridDragOver
-      if (!dropElement || dropElement.hasAttribute("zen-essential")) {
+      if (!dropElement) {
         this.clearDragOverVisuals();
-        // If dropElement is null or essential, dropElement should be the empty tab
+        return [undefined, null];
+      }
+      // Essentials should be properly handled by ::animateVerticalPinnedGridDragOver
+      if (dropElement.hasAttribute("zen-essential")) {
+        this.clearDragOverVisuals();
+        // If dropElement is essential, dropElement should be the empty tab
         return [dropBefore, gZenWorkspaces._emptyTab];
       }
       if (dropElement.hasAttribute("zen-empty-tab") && dropElement.group) {

src/zen/folders/ZenFolders.mjs

@@ -183,6 +183,9 @@ class nsZenFolders extends nsZenDOMOperatedFeature {
         case "context_zenFolderChangeIcon":
           this.changeFolderUserIcon(this.#lastFolderContextMenu);
           break;
+        case "context_zenShareFolder":
+          gZenShareManager.shareFolder(this.#lastFolderContextMenu);
+          break;
       }
     });
   }

src/zen/folders/jar.inc.mn

@@ -4,4 +4,4 @@
 
         content/browser/zen-components/ZenFolder.mjs                            (../../zen/folders/ZenFolder.mjs)
         content/browser/zen-components/ZenFolders.mjs                           (../../zen/folders/ZenFolders.mjs)
-        content/browser/zen-styles/zen-folders.css                              (../../zen/folders/zen-folders.css)
+*       content/browser/zen-styles/zen-folders.css                              (../../zen/folders/zen-folders.css)

src/zen/folders/zen-folder-icon.inc.css

@@ -0,0 +1,19 @@
+/* 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/. */
+
+& g,
+& rect,
+& path {
+  transition:
+    transform 0.3s cubic-bezier(0.42, 0, 0, 1),
+    opacity 0.3s cubic-bezier(0.42, 0, 0, 1);
+}
+
+&[state="open"] .back {
+  transform: skewX(16deg) translate(-4px, 2px) scale(0.85);
+}
+
+&[state="open"] :is(.front, .dots, .icon) {
+  transform: skewX(-16deg) translate(8px, 2px) scale(0.85);
+}

src/zen/folders/zen-folders.css

@@ -8,15 +8,17 @@
   display: none !important;
 }
 
+:root {
+  --zen-folder-behind-bgcolor: light-dark(color-mix(in srgb, var(--zen-primary-color) 60%, gray), color-mix(in srgb, var(--zen-primary-color) 60%, #c1c1c1));
+  --zen-folder-front-bgcolor: light-dark(color-mix(in srgb, var(--zen-primary-color), white 70%), color-mix(in srgb, var(--zen-primary-color), black 40%));
+  --zen-folder-stroke: light-dark(color-mix(in srgb, var(--zen-primary-color) 50%, black), color-mix(in srgb, var(--zen-colors-primary) 15%, #ebebeb));
+}
+
 zen-folder {
   display: flex;
   flex-direction: column;
   visibility: visible;
 
-  --zen-folder-behind-bgcolor: light-dark(color-mix(in srgb, var(--zen-primary-color) 60%, gray), color-mix(in srgb, var(--zen-primary-color) 60%, #c1c1c1));
-  --zen-folder-front-bgcolor: light-dark(color-mix(in srgb, var(--zen-primary-color), white 70%), color-mix(in srgb, var(--zen-primary-color), black 40%));
-  --zen-folder-stroke: light-dark(color-mix(in srgb, var(--zen-primary-color) 50%, black), color-mix(in srgb, var(--zen-colors-primary) 15%, #ebebeb));
-
   -moz-window-dragging: no-drag;
   transition: var(--zen-tabbox-element-indent-transition);
 
@@ -114,21 +116,7 @@ zen-folder {
           transform: translate(8.5px, 10.5px);
         }
 
-        & g,
-        & rect,
-        & path {
-          transition:
-            transform 0.3s cubic-bezier(0.42, 0, 0, 1),
-            opacity 0.3s cubic-bezier(0.42, 0, 0, 1);
-        }
-
-        &[state="open"] .back {
-          transform: skewX(16deg) translate(-4px, 2px) scale(0.85);
-        }
-
-        &[state="open"] :is(.front, .dots, .icon) {
-          transform: skewX(-16deg) translate(8px, 2px) scale(0.85);
-        }
+%include zen-folder-icon.inc.css
 
         & .icon {
           opacity: 1;

src/zen/glance/ZenGlanceManager.mjs

@@ -392,7 +392,7 @@ class nsZenGlanceManager extends nsZenDOMOperatedFeature {
       return Promise.resolve(this.#currentTab);
     }
 
-    // Existing-tab glances perform no navigation and are exempt; for fresh
+    // Existing-tab glances perform no navigation and are exempt. For fresh
     // loads, refuse any URL the triggering principal isn't allowed to load
     // (e.g. a web page linking to file://).
     if (!existingTab && !this.#isGlanceLoadAllowed(data)) {

src/zen/glance/actors/ZenGlanceChild.sys.mjs

@@ -17,12 +17,18 @@ XPCOMUtils.defineLazyPreferenceGetter(
   true
 );
 
+XPCOMUtils.defineLazyPreferenceGetter(
+  lazy,
+  "activationMethod",
+  "zen.glance.activation-method",
+  "ctrl"
+);
+
 // A small threshold to allow for minor mouse jitter during a normal click.
 // Anything beyond this is likely an intentional drag (like selecting text).
 const CLICK_DRAG_THRESHOLD_PX = 4;
 
 export class ZenGlanceChild extends JSWindowActorChild {
-  #activationMethod;
   #mouseDownX = null;
   #mouseDownY = null;
 
@@ -37,12 +43,6 @@ export class ZenGlanceChild extends JSWindowActorChild {
     }
   }
 
-  async #initActivationMethod() {
-    this.#activationMethod = await this.sendQuery(
-      "ZenGlance:GetActivationMethod"
-    );
-  }
-
   #ensureOnlyKeyModifiers(event) {
     return !(event.ctrlKey ^ event.altKey ^ event.shiftKey ^ event.metaKey);
   }
@@ -156,7 +156,7 @@ export class ZenGlanceChild extends JSWindowActorChild {
     ) {
       return;
     }
-    const activationMethod = this.#activationMethod;
+    const activationMethod = lazy.activationMethod;
     if (activationMethod === "ctrl" && !event.ctrlKey) {
       return;
     } else if (activationMethod === "alt" && !event.altKey) {
@@ -184,8 +184,4 @@ export class ZenGlanceChild extends JSWindowActorChild {
         this.contentWindow.document.body,
     });
   }
-
-  async on_DOMContentLoaded() {
-    await this.#initActivationMethod();
-  }
 }

src/zen/glance/actors/ZenGlanceParent.sys.mjs

@@ -11,12 +11,6 @@ export class ZenGlanceParent extends JSWindowActorParent {
 
   async receiveMessage(message) {
     switch (message.name) {
-      case "ZenGlance:GetActivationMethod": {
-        return Services.prefs.getStringPref(
-          "zen.glance.activation-method",
-          "ctrl"
-        );
-      }
       case "ZenGlance:OpenGlance": {
         this.openGlance(this.browsingContext.topChromeWindow, message.data);
         break;

src/zen/glance/zen-glance.css

@@ -105,6 +105,11 @@
 .browserSidebarContainer.zen-glance-background,
 .browserSidebarContainer.zen-glance-overlay .browserContainer:not([fade-out="true"]) {
   border-radius: var(--zen-native-inner-radius);
+  @media not (-moz-pref("zen.theme.squircle-browser-view")) {
+    /* stylelint-disable-next-line property-no-unknown */
+    corner-shape: round;
+    border-radius: calc(var(--zen-native-inner-radius) / var(--zen-squircle-value));
+  }
 }
 
 .browserSidebarContainer.zen-glance-overlay {
@@ -144,6 +149,11 @@
       border-radius: var(--zen-native-inner-radius);
       overflow: hidden;
       box-shadow: var(--zen-big-shadow);
+      @media not (-moz-pref("zen.theme.squircle-browser-view")) {
+        /* stylelint-disable-next-line property-no-unknown */
+        corner-shape: round;
+        border-radius: calc(var(--zen-native-inner-radius) / var(--zen-squircle-value));
+      }
     }
 
     & browser {

src/zen/mods/ZenMods.mjs

@@ -524,13 +524,20 @@ class nsZenMods extends nsZenPreloadedFeature {
       console.error("[ZenMods]: Error loading Zen Mods:", e);
     }
 
-    Services.prefs.addObserver(
-      this.updatePref,
-      this.#rebuildModsStylesheet.bind(this)
-    );
-    Services.prefs.addObserver(
-      "zen.themes.disable-all",
-      this.#handleDisableMods.bind(this)
+    const rebuildObserver = this.#rebuildModsStylesheet.bind(this);
+    const disableObserver = this.#handleDisableMods.bind(this);
+    Services.prefs.addObserver(this.updatePref, rebuildObserver);
+    Services.prefs.addObserver("zen.themes.disable-all", disableObserver);
+    window.addEventListener(
+      "unload",
+      () => {
+        Services.prefs.removeObserver(this.updatePref, rebuildObserver);
+        Services.prefs.removeObserver(
+          "zen.themes.disable-all",
+          disableObserver
+        );
+      },
+      { once: true }
     );
   }
 

src/zen/share/ZenShareClient.sys.mjs

@@ -0,0 +1,238 @@
+// 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 { AppConstants } from "resource://gre/modules/AppConstants.sys.mjs";
+import { XPCOMUtils } from "resource://gre/modules/XPCOMUtils.sys.mjs";
+
+const lazy = {};
+
+ChromeUtils.defineESModuleGetters(lazy, {
+  JsonSchema: "resource://gre/modules/JsonSchema.sys.mjs",
+  clearTimeout: "resource://gre/modules/Timer.sys.mjs",
+  setTimeout: "resource://gre/modules/Timer.sys.mjs",
+});
+
+XPCOMUtils.defineLazyPreferenceGetter(
+  lazy,
+  "gBaseUrl",
+  "zen.share.base-url",
+  "",
+  null,
+  value => value.trim().replace(/\/+$/, "")
+);
+
+XPCOMUtils.defineLazyPreferenceGetter(
+  lazy,
+  "gSecretKey",
+  "zen.share.secret-key",
+  ""
+);
+
+const SCHEMA_URL = "resource:///modules/zen/share/share.schema.json";
+
+// The server rejects bigger bodies at 25 MiB.
+const MAX_SHARE_BYTES = 25 * 1024 * 1024;
+const MAX_NAME_LENGTH = 200;
+
+// Uploads can be tens of MiB, reads are small JSON.
+const CREATE_TIMEOUT_MS = 120000;
+const READ_TIMEOUT_MS = 30000;
+
+// Public share page paths: /{slug}/{XXXX-XXXX-XXXX-XXXX id}.
+const SHARE_PATH_RE =
+  /^\/(space|folder|split-view|split)\/([0-9A-Za-z]{4}-[0-9A-Za-z]{4}-[0-9A-Za-z]{4}-[0-9A-Za-z]{4})\/?$/;
+
+export class ZenShareError extends Error {
+  /**
+   * @param {string} code - One of "invalid-document", "auth", "too-large",
+   *      "rate-limited", "not-found", "network", "server".
+   * @param {string} message
+   */
+  constructor(code, message) {
+    super(message);
+    this.name = "ZenShareError";
+    this.code = code;
+  }
+}
+
+class nsZenShareClient {
+  #validatorPromise = null;
+
+  get #baseUrl() {
+    return lazy.gBaseUrl;
+  }
+
+  #authHeaders() {
+    // A secret key authorizes on its own and makes the share permanent. Never
+    // send both keys.
+    if (lazy.gSecretKey) {
+      return { "x-secret-key": lazy.gSecretKey };
+    }
+    return { "x-api-key": AppConstants.MOZ_MOZILLA_API_KEY };
+  }
+
+  #getValidator() {
+    if (!this.#validatorPromise) {
+      this.#validatorPromise = fetch(SCHEMA_URL, { credentials: "omit" })
+        .then(response => response.json())
+        .then(schema => new lazy.JsonSchema.Validator(schema));
+    }
+    return this.#validatorPromise;
+  }
+
+  /**
+   * Validates a share document against the schema.
+   *
+   * @param {object} doc
+   * @returns {Promise<{valid: boolean, errors: object[]}>}
+   */
+  async validateDocument(doc) {
+    const validator = await this.#getValidator();
+    return validator.validate(doc);
+  }
+
+  async #assertValidDocument(doc) {
+    const result = await this.validateDocument(doc);
+    if (!result.valid) {
+      console.error("ZenShare: document fails the schema", result.errors);
+      throw new ZenShareError(
+        "invalid-document",
+        "share document fails the schema"
+      );
+    }
+  }
+
+  async #request(url, options, timeoutMs = READ_TIMEOUT_MS) {
+    const controller = new AbortController();
+    const timer = lazy.setTimeout(() => controller.abort(), timeoutMs);
+    let response;
+    try {
+      response = await fetch(url, {
+        credentials: "omit",
+        signal: controller.signal,
+        ...options,
+      });
+    } catch (e) {
+      throw new ZenShareError(
+        "network",
+        `could not reach ${url}: ${e.message}`
+      );
+    } finally {
+      lazy.clearTimeout(timer);
+    }
+    if (response.ok) {
+      return response;
+    }
+    let message = `${response.status}`;
+    try {
+      message = (await response.json()).error || message;
+    } catch (e) {}
+    switch (response.status) {
+      case 401:
+      case 403:
+        throw new ZenShareError("auth", message);
+      case 404:
+        throw new ZenShareError("not-found", message);
+      case 413:
+        throw new ZenShareError("too-large", message);
+      case 429:
+        throw new ZenShareError("rate-limited", message);
+      case 400:
+      case 422:
+        throw new ZenShareError("invalid-document", message);
+      default:
+        throw new ZenShareError("server", message);
+    }
+  }
+
+  /**
+   * Uploads a share document.
+   *
+   * @param {object} doc - A document conforming to share.schema.json.
+   * @param {{name?: string}} options - Optional sharer display name, shown on
+   *   the share page as "A Space from {name}".
+   * @returns {Promise<object>} The create response, plus `link`: the absolute
+   *   public page URL to hand to the user.
+   */
+  async createShare(doc, { name } = {}) {
+    const base = this.#baseUrl;
+    const headers = this.#authHeaders();
+    await this.#assertValidDocument(doc);
+    const body = JSON.stringify(doc);
+    if (new TextEncoder().encode(body).length > MAX_SHARE_BYTES) {
+      throw new ZenShareError("too-large", "share document is over 25 MiB");
+    }
+    let url = `${base}/api/shares`;
+    if (name) {
+      url += `?name=${encodeURIComponent(name.slice(0, MAX_NAME_LENGTH))}`;
+    }
+    const response = await this.#request(
+      url,
+      {
+        method: "POST",
+        headers: { ...headers, "content-type": "application/json" },
+        body,
+      },
+      CREATE_TIMEOUT_MS
+    );
+    const created = await response.json();
+    return { ...created, link: base + created.webUrl };
+  }
+
+  /**
+   * Recognizes public share page URLs on the configured server.
+   *
+   * @param {string} spec
+   * @returns {?{type: string, id: string}} null when the URL is not a share
+   *   page (or no server is configured).
+   */
+  parseShareUrl(spec) {
+    let uri;
+    let baseUri;
+    try {
+      uri = Services.io.newURI(spec);
+      baseUri = Services.io.newURI(this.#baseUrl);
+    } catch (e) {
+      return null;
+    }
+    if (uri.prePath !== baseUri.prePath) {
+      return null;
+    }
+    const match = uri.filePath.match(SHARE_PATH_RE);
+    if (!match) {
+      return null;
+    }
+    const slug = match[1];
+    const type = slug === "split" ? "split-view" : slug;
+    return { type, id: match[2].toUpperCase() };
+  }
+
+  /**
+   * Fetches everything needed to preview and import a share: the validated
+   * document, plus the sharer's display name.
+   *
+   * @param {{id: string}} share - As returned by parseShareUrl.
+   * @returns {Promise<{doc: object, name: ?string}>}
+   */
+  async fetchSharePreview(share) {
+    const meta = await this.getShare(share.id);
+    await this.#assertValidDocument(meta.data);
+    return { doc: meta.data, name: meta.name || null };
+  }
+
+  /**
+   * Fetches a share with its metadata (authed):
+   * { id, name, createdAt, expiresAt, size, data }.
+   *
+   * @param {string} id
+   */
+  async getShare(id) {
+    const response = await this.#request(`${this.#baseUrl}/api/shares/${id}`, {
+      headers: this.#authHeaders(),
+    });
+    return response.json();
+  }
+}
+
+export const ZenShareClient = new nsZenShareClient();

src/zen/share/ZenShareManager.mjs

@@ -0,0 +1,821 @@
+// 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 { nsZenDOMOperatedFeature } from "chrome://browser/content/zen-components/ZenCommonUtils.mjs";
+import { nsZenThemePicker } from "resource:///modules/zen/ZenGradientGenerator.mjs";
+
+const lazy = {};
+
+ChromeUtils.defineESModuleGetters(lazy, {
+  TabStateCache: "resource:///modules/sessionstore/TabStateCache.sys.mjs",
+  ZenShareClient: "resource:///modules/zen/share/ZenShareClient.sys.mjs",
+  ZenShareError: "resource:///modules/zen/share/ZenShareClient.sys.mjs",
+});
+
+const SHARE_DOCUMENT_VERSION = "1";
+
+const SHAREABLE_ICON_RE = /^(data:|chrome:)/;
+const FOLDER_ICON_RE = /^chrome:\/\//;
+
+/**
+ * Shares spaces, folders and split views through the share server, and
+ * imports them back from share links.
+ */
+class nsZenShareManager extends nsZenDOMOperatedFeature {
+  init() {
+    if (!this.enabled) {
+      for (const id of [
+        "context_zenShareWorkspace",
+        "context_zenShareFolder",
+      ]) {
+        document.getElementById(id)?.setAttribute("hidden", "true");
+      }
+      return;
+    }
+    delayedStartupPromise.then(() => {
+      gBrowser.addTabsProgressListener({
+        onLocationChange: (browser, webProgress, request, aLocation) => {
+          this.#onLocationChange(browser, webProgress, aLocation);
+        },
+      });
+    });
+  }
+
+  get enabled() {
+    return !gZenWorkspaces.privateWindowOrDisabled;
+  }
+
+  // Mark: sharing
+
+  async shareSpace(workspaceId) {
+    const workspace = gZenWorkspaces.getWorkspaceFromId(workspaceId);
+    const element = gZenWorkspaces.workspaceElement(workspaceId);
+    if (!workspace || !element) {
+      return;
+    }
+    const item = {
+      type: "space",
+      name: workspace.name || "Space",
+      items: [
+        ...this.#serializeItems(element.pinnedTabsContainer.children, {
+          pinned: true,
+        }),
+        ...this.#serializeItems(element.tabsContainer.children, {
+          pinned: false,
+        }),
+      ],
+    };
+    const theme = this.#serializeTheme(workspace.theme);
+    if (theme) {
+      item.theme = theme;
+    }
+    await this.#createAndCopyLink(item);
+  }
+
+  async shareFolder(folder) {
+    if (!folder?.isZenFolder) {
+      return;
+    }
+    await this.#createAndCopyLink(this.#serializeFolder(folder));
+  }
+
+  async shareSplitView(group) {
+    if (!group?.hasAttribute("split-view-group")) {
+      return;
+    }
+    const item = this.#serializeSplitGroup(group);
+    if (!item) {
+      this.#showCreateError(
+        new lazy.ZenShareError("empty", "nothing to share")
+      );
+      return;
+    }
+    await this.#createAndCopyLink(item);
+  }
+
+  #serializeSplitGroup(group) {
+    const tabs = group.tabs
+      .filter(tab => !tab.hasAttribute("zen-empty-tab"))
+      .map(tab => this.#serializeTab(tab, { pinned: tab.pinned }))
+      .filter(Boolean);
+    return tabs.length >= 2
+      ? { type: "splitView", tabs: tabs.slice(0, gZenViewSplitter.MAX_TABS) }
+      : null;
+  }
+
+  async #createAndCopyLink(item) {
+    if (!this.enabled) {
+      return;
+    }
+    if (!(await this.#confirmShare())) {
+      return;
+    }
+    try {
+      const created = await lazy.ZenShareClient.createShare(
+        { version: SHARE_DOCUMENT_VERSION, shared: item },
+        { name: this.#displayName() }
+      );
+      Cc["@mozilla.org/widget/clipboardhelper;1"]
+        .getService(Ci.nsIClipboardHelper)
+        .copyString(created.link);
+      // The description's l10n args come from the whole options object.
+      gZenUIManager.showToast("zen-share-link-copied-toast", {
+        descriptionId: created.expiresAt
+          ? "zen-share-link-expires-description"
+          : "zen-share-link-permanent-description",
+        date: created.expiresAt
+          ? new Date(created.expiresAt).toLocaleDateString()
+          : "",
+        timeout: 6000,
+      });
+    } catch (e) {
+      this.#showCreateError(e);
+    }
+  }
+
+  #displayName() {
+    return (
+      Services.prefs.getStringPref("zen.share.display-name", "") || undefined
+    );
+  }
+
+  async #confirmShare() {
+    if (
+      Services.prefs.getBoolPref("zen.share.dont-ask-before-sharing", false)
+    ) {
+      return true;
+    }
+    const args = {
+      accepted: false,
+      name: Services.prefs.getStringPref("zen.share.display-name", ""),
+    };
+    await gDialogBox.open(
+      "chrome://browser/content/zen-components/windows/zen-share-confirm.xhtml",
+      args
+    );
+    if (args.accepted) {
+      Services.prefs.setStringPref("zen.share.display-name", args.name);
+      if (args.dontAsk) {
+        Services.prefs.setBoolPref("zen.share.dont-ask-before-sharing", true);
+      }
+    }
+    return args.accepted;
+  }
+
+  #showCreateError(error) {
+    console.error("ZenShare: could not create share:", error);
+    const descriptions = {
+      auth: "zen-share-error-auth-description",
+      "too-large": "zen-share-error-too-large-description",
+      "rate-limited": "zen-share-error-rate-limited-description",
+      network: "zen-share-error-network-description",
+      empty: "zen-share-error-empty-description",
+    };
+    gZenUIManager.showToast("zen-share-error-toast", {
+      descriptionId:
+        descriptions[error.code] || "zen-share-error-server-description",
+      timeout: 6000,
+    });
+  }
+
+  // Mark: serialization
+
+  #serializeItems(children, { pinned }) {
+    const items = [];
+    for (const child of children) {
+      if (gBrowser.isTab(child)) {
+        if (
+          child.hasAttribute("zen-empty-tab") ||
+          child.hasAttribute("zen-glance-tab")
+        ) {
+          continue;
+        }
+        const tab = this.#serializeTab(child, { pinned });
+        if (tab) {
+          items.push(tab);
+        }
+      } else if (child.isZenFolder) {
+        items.push(this.#serializeFolder(child));
+      } else if (gBrowser.isTabGroup(child)) {
+        const split = child.hasAttribute("split-view-group")
+          ? this.#serializeSplitGroup(child)
+          : null;
+        if (split) {
+          items.push(split);
+          continue;
+        }
+        // Plain tab groups (and degenerate splits) keep their member tabs.
+        for (const tab of child.tabs) {
+          if (tab.hasAttribute("zen-empty-tab")) {
+            continue;
+          }
+          const serialized = this.#serializeTab(tab, { pinned });
+          if (serialized) {
+            items.push(serialized);
+          }
+        }
+      }
+    }
+    return items;
+  }
+
+  #serializeFolder(folder) {
+    const item = {
+      type: "folder",
+      name: folder.label || "Folder",
+      items: this.#serializeItems(folder.allItems, { pinned: false }),
+    };
+    const icon = folder.iconURL;
+    if (icon) {
+      item.icon = icon;
+    }
+    return item;
+  }
+
+  #serializeTab(tab, { pinned = false } = {}) {
+    const url = tab.linkedBrowser?.currentURI?.spec;
+    if (!url || !/^https?:\/\//.test(url)) {
+      return null;
+    }
+    const item = { type: "tab", url };
+    const label = tab.label;
+    if (label) {
+      item.label = label;
+    }
+    const image = this.#serializeIcon(tab);
+    if (image) {
+      item.image = image;
+    }
+    if (pinned) {
+      item.isPinned = true;
+    }
+    return item;
+  }
+
+  #serializeIcon(tab) {
+    let icon = tab.getAttribute("image") || "";
+    if (icon.startsWith("moz-remote-image:")) {
+      try {
+        icon =
+          new URLSearchParams(Services.io.newURI(icon).query).get("url") || "";
+      } catch (e) {
+        return "";
+      }
+    }
+    return SHAREABLE_ICON_RE.test(icon) ? icon : "";
+  }
+
+  #serializeTheme(theme) {
+    if (theme?.type !== "gradient" || !Array.isArray(theme.gradientColors)) {
+      return null;
+    }
+    const gradientColors = theme.gradientColors
+      .map(color => this.#serializeGradientColor(color))
+      .filter(Boolean);
+    if (!gradientColors.length) {
+      return null;
+    }
+    return { type: "gradient", gradientColors };
+  }
+
+  #serializeGradientColor(color) {
+    let c = color?.c;
+    if (typeof c === "string") {
+      c = this.#parseCssColor(c);
+    } else if (Array.isArray(c)) {
+      c = c.slice(0, 3).map(Number);
+    }
+    if (
+      !Array.isArray(c) ||
+      c.length !== 3 ||
+      c.some(n => !Number.isFinite(n))
+    ) {
+      return null;
+    }
+    const out = { c, type: typeof color.type === "string" ? color.type : "" };
+    if (typeof color.isCustom === "boolean") {
+      out.isCustom = color.isCustom;
+    }
+    if (typeof color.isPrimary === "boolean") {
+      out.isPrimary = color.isPrimary;
+    }
+    if (typeof color.algorithm === "string") {
+      out.algorithm = color.algorithm;
+    }
+    if (color.lightness !== undefined && color.lightness !== null) {
+      out.lightness = String(color.lightness);
+    }
+    if (
+      Number.isFinite(color.position?.x) &&
+      Number.isFinite(color.position?.y)
+    ) {
+      out.position = { x: color.position.x, y: color.position.y };
+    }
+    return out;
+  }
+
+  #parseCssColor(value) {
+    const hex = value.trim().match(/^#([0-9a-f]{3}|[0-9a-f]{6})$/i)?.[1];
+    if (hex) {
+      const full =
+        hex.length === 3 ? [...hex].map(ch => ch + ch).join("") : hex;
+      return [0, 2, 4].map(i => parseInt(full.slice(i, i + 2), 16));
+    }
+    const numbers = value
+      .match(/\d+(\.\d+)?/g)
+      ?.slice(0, 3)
+      .map(Number);
+    return numbers?.length === 3 ? numbers : null;
+  }
+
+  // Mark: importing
+
+  #stylesLoaded = false;
+
+  // The overlay styles are only needed once a share link is opened.
+  #ensureStyles() {
+    if (this.#stylesLoaded) {
+      return;
+    }
+    this.#stylesLoaded = true;
+    window.windowUtils.loadSheetUsingURIString(
+      "chrome://browser/content/zen-styles/zen-share.css",
+      window.windowUtils.AUTHOR_SHEET
+    );
+  }
+
+  #setHostTabSubtitle(browser, subtitle) {
+    const tab = gBrowser.getTabForBrowser(browser);
+    if (!tab) {
+      return;
+    }
+    tab.setAttribute("zen-show-sublabel", subtitle);
+    document.l10n.setArgs(tab.querySelector(".zen-tab-sublabel"), {
+      tabSubtitle: subtitle,
+    });
+  }
+
+  #clearHostTabSubtitle(browser) {
+    const tab = gBrowser.getTabForBrowser(browser);
+    if (!tab?.hasAttribute("zen-show-sublabel")) {
+      return;
+    }
+    tab.removeAttribute("zen-show-sublabel");
+    document.l10n.setArgs(tab.querySelector(".zen-tab-sublabel"), {
+      tabSubtitle: "zen-default-pinned",
+    });
+  }
+
+  #onLocationChange(browser, webProgress, aLocation) {
+    if (!webProgress.isTopLevel) {
+      return;
+    }
+    if (browser._zenShareOverlay) {
+      browser._zenShareOverlay.remove();
+      delete browser._zenShareOverlay;
+      browser.removeAttribute("zen-share-overlay-showing");
+      this.#clearHostTabSubtitle(browser);
+    }
+    const share = lazy.ZenShareClient.parseShareUrl(aLocation.spec);
+    if (!share) {
+      return;
+    }
+    if (share.type === "split-view") {
+      // Split views are light enough to open right away, no preview step.
+      this.#openSharedSplitView(browser, share);
+    } else {
+      this.#showImportOverlay(browser, share);
+    }
+  }
+
+  async #openSharedSplitView(browser, share) {
+    let item;
+    const shareTab = gBrowser.getTabForBrowser(browser);
+    shareTab.style.display = "none";
+    const failure = () => {
+      shareTab.style.removeProperty("display");
+    };
+    try {
+      const { doc } = await lazy.ZenShareClient.fetchSharePreview(share);
+      item = doc.shared?.type === "splitView" ? doc.shared : null;
+    } catch (e) {
+      console.error("ZenShare: could not load shared split view:", e);
+      const descriptions = {
+        "not-found": "zen-share-import-error-dead-description",
+        "invalid-document": "zen-share-import-error-invalid-description",
+      };
+      gZenUIManager.showToast("zen-share-import-error-toast", {
+        descriptionId:
+          descriptions[e.code] || "zen-share-error-network-description",
+        timeout: 6000,
+      });
+      failure();
+      return;
+    }
+    if (!item) {
+      failure();
+      return;
+    }
+    const workspaceId = gZenWorkspaces.activeWorkspace;
+    const pinned = item.tabs.every(child => child.isPinned);
+    const tabs = item.tabs.map(child => {
+      // Eager browsers so every pane renders as soon as the split shows.
+      const tab = this.#importTab(child, workspaceId, { lazyBrowser: false });
+      if (pinned) {
+        gBrowser.pinTab(tab);
+      }
+      this.#placeTab(tab, workspaceId, pinned);
+      return tab;
+    });
+    gZenViewSplitter.splitTabs(tabs, "grid", 0);
+    gBrowser.removeTab(shareTab, {
+      closeWindowWithLastTab: false,
+      skipSessionStore: true,
+    });
+    // Shake the new split group in the sidebar.
+    const group = tabs[0]?.group;
+    if (group?.hasAttribute("split-view-group")) {
+      requestAnimationFrame(() => {
+        gZenUIManager.motion
+          .animate(
+            group,
+            { x: [-28, 0] },
+            { type: "spring", bounce: 0.9, duration: 1.4 }
+          )
+          .then(() => {
+            group.style.removeProperty("transform");
+          });
+      });
+    }
+  }
+
+  async #showImportOverlay(browser, share) {
+    const stack = browser.closest(".browserStack");
+    if (!stack) {
+      return;
+    }
+    this.#ensureStyles();
+    // Only the status text shows until the preview loads.
+    const overlay = window.MozXULElement.parseXULToFragment(`
+      <html:div class="zen-share-overlay">
+        <html:div class="zen-share-overlay-card">
+          <html:div class="zen-share-overlay-items"/>
+          <html:div class="zen-share-overlay-status"
+                    data-l10n-id="zen-share-overlay-loading"/>
+          <html:div class="zen-share-overlay-footer" hidden="hidden">
+            <html:div class="zen-share-overlay-badge-stack">
+              <html:div class="zen-share-overlay-badge-sheet second"/>
+              <html:div class="zen-share-overlay-badge-sheet first"/>
+              <html:div class="zen-share-overlay-badge">
+                <html:img class="zen-share-overlay-badge-icon"
+                          draggable="false"/>
+                <html:div class="zen-share-overlay-badge-text">
+                  <html:div class="zen-share-overlay-badge-title"/>
+                  <html:div class="zen-share-overlay-badge-subtitle"/>
+                </html:div>
+              </html:div>
+            </html:div>
+          </html:div>
+        </html:div>
+        <html:button class="zen-big-accent-button primary zen-share-overlay-add"
+                     hidden="hidden" disabled="disabled"/>
+      </html:div>
+    `).firstElementChild;
+    const items = overlay.querySelector(".zen-share-overlay-items");
+    const statusEl = overlay.querySelector(".zen-share-overlay-status");
+    const footer = overlay.querySelector(".zen-share-overlay-footer");
+    const badgeIcon = overlay.querySelector(".zen-share-overlay-badge-icon");
+    const badgeTitle = overlay.querySelector(".zen-share-overlay-badge-title");
+    const badgeSubtitle = overlay.querySelector(
+      ".zen-share-overlay-badge-subtitle"
+    );
+    const button = overlay.querySelector(".zen-share-overlay-add");
+
+    stack.appendChild(overlay);
+    browser._zenShareOverlay = overlay;
+    browser.setAttribute("zen-share-overlay-showing", "true");
+
+    let preview;
+    try {
+      preview = await lazy.ZenShareClient.fetchSharePreview(share);
+    } catch (e) {
+      console.error("ZenShare: could not load share preview:", e);
+      const descriptions = {
+        "not-found": "zen-share-import-error-dead-description",
+        "invalid-document": "zen-share-import-error-invalid-description",
+      };
+      document.l10n.setAttributes(
+        statusEl,
+        descriptions[e.code] || "zen-share-error-network-description"
+      );
+      return;
+    }
+    if (browser._zenShareOverlay !== overlay) {
+      // Navigated away while loading.
+      return;
+    }
+    const { doc, name: sharerName } = preview;
+    const first = doc.shared;
+    const type = first.type;
+
+    badgeTitle.textContent = first.name;
+    this.#renderPreviewRows(items, first.items);
+    if (type === "folder") {
+      // The real zen folder icon, with the shared custom icon when set.
+      const folderIcon = this.#buildFolderIcon(first.icon);
+      folderIcon.classList.add("zen-share-overlay-badge-icon");
+      folderIcon.setAttribute("state", "open");
+      badgeIcon.replaceWith(folderIcon);
+    } else {
+      badgeIcon.src = "chrome://browser/skin/zen-icons/duplicate-tab.svg";
+    }
+    if (sharerName) {
+      document.l10n.setAttributes(
+        badgeSubtitle,
+        `zen-share-overlay-from-${type}`,
+        { name: sharerName }
+      );
+    } else {
+      document.l10n.setAttributes(
+        badgeSubtitle,
+        "zen-share-overlay-shared-with-you"
+      );
+    }
+    // Mirror the badge subtitle under the tab's label, like live folders do.
+    const [tabSubtitle] = await document.l10n.formatValues([
+      sharerName
+        ? { id: `zen-share-overlay-from-${type}`, args: { name: sharerName } }
+        : { id: "zen-share-overlay-shared-with-you" },
+    ]);
+    this.#setHostTabSubtitle(browser, tabSubtitle);
+    statusEl.remove();
+    footer.hidden = false;
+    document.l10n.setAttributes(button, `zen-share-overlay-add-${type}`);
+    button.hidden = false;
+    button.disabled = false;
+    button.addEventListener("click", async () => {
+      button.disabled = true;
+      try {
+        await this.#importDocument(doc);
+        gZenUIManager.showToast("zen-share-imported-toast");
+        const tab = gBrowser.getTabForBrowser(browser);
+        if (tab) {
+          gBrowser.removeTab(tab, {
+            closeWindowWithLastTab: false,
+            skipSessionStore: true,
+          });
+        }
+      } catch (e) {
+        console.error("ZenShare: could not import share:", e);
+        gZenUIManager.showToast("zen-share-import-error-toast", {
+          timeout: 6000,
+        });
+        button.disabled = false;
+      }
+    });
+  }
+
+  #renderPreviewRows(container, entries) {
+    for (const entry of entries) {
+      if (entry.type === "folder") {
+        container.appendChild(this.#buildFolderRow(entry));
+      } else if (entry.type === "splitView") {
+        const split = window.MozXULElement.parseXULToFragment(`
+          <html:div class="zen-share-overlay-split"/>
+        `).firstElementChild;
+        for (const tab of entry.tabs) {
+          split.appendChild(this.#buildTabRow(tab));
+        }
+        container.appendChild(split);
+      } else {
+        container.appendChild(this.#buildTabRow(entry));
+      }
+    }
+  }
+
+  #buildTabRow(entry) {
+    const row = window.MozXULElement.parseXULToFragment(`
+      <html:div class="zen-share-overlay-row">
+        <html:img class="zen-share-overlay-row-icon" draggable="false"/>
+        <html:div class="zen-share-overlay-row-label"/>
+      </html:div>
+    `).firstElementChild;
+    row.title = entry.url;
+    row.querySelector(".zen-share-overlay-row-icon").src =
+      entry.image && SHAREABLE_ICON_RE.test(entry.image)
+        ? entry.image
+        : `page-icon:${entry.url}`;
+    row.querySelector(".zen-share-overlay-row-label").textContent =
+      entry.label || entry.url;
+    row.addEventListener("click", () => {
+      const stackRect = row.closest(".browserStack").getBoundingClientRect();
+      const data = {
+        url: entry.url,
+        clientX: stackRect.width / 2,
+        clientY: stackRect.height / 2,
+        width: 0,
+        height: 0,
+        triggeringPrincipal:
+          Services.scriptSecurityManager.getSystemPrincipal(),
+      };
+      gZenGlanceManager.lastLinkClickData = data;
+      gZenGlanceManager.openGlance(data);
+    });
+    return row;
+  }
+
+  #buildFolderRow(entry) {
+    const wrapper = window.MozXULElement.parseXULToFragment(`
+      <html:div class="zen-share-overlay-folder" collapsed="true">
+        <html:div class="zen-share-overlay-row">
+          <html:div class="zen-share-overlay-row-label"/>
+        </html:div>
+        <html:div class="zen-share-overlay-children-clip">
+          <html:div class="zen-share-overlay-children"/>
+        </html:div>
+      </html:div>
+    `).firstElementChild;
+    const row = wrapper.querySelector(".zen-share-overlay-row");
+    const label = row.querySelector(".zen-share-overlay-row-label");
+    label.textContent = entry.name;
+    const icon = this.#buildFolderIcon(entry.icon);
+    row.insertBefore(icon, label);
+    this.#renderPreviewRows(
+      wrapper.querySelector(".zen-share-overlay-children"),
+      entry.items
+    );
+    row.addEventListener("click", () => {
+      const collapsed = wrapper.toggleAttribute("collapsed");
+      if (collapsed) {
+        icon.removeAttribute("state");
+      } else {
+        icon.setAttribute("state", "open");
+      }
+    });
+    return wrapper;
+  }
+
+  #buildFolderIcon(customIcon) {
+    const { nsZenFolder } = ChromeUtils.importESModule(
+      "chrome://browser/content/zen-components/ZenFolder.mjs",
+      { global: "current" }
+    );
+    const svg = nsZenFolder.rawIcon.cloneNode(true);
+    svg.classList.add("zen-share-overlay-folder-icon");
+    if (customIcon && FOLDER_ICON_RE.test(customIcon)) {
+      svg.querySelector(".icon image").setAttribute("href", customIcon);
+    }
+    return svg;
+  }
+
+  async #importDocument(doc) {
+    const item = doc.shared;
+    switch (item.type) {
+      case "space":
+        await this.#importSpace(item);
+        break;
+      case "folder":
+        this.#importFolder(item, gZenWorkspaces.activeWorkspace);
+        break;
+      case "splitView":
+        this.#importSplitView(item);
+        break;
+    }
+  }
+
+  async #importSpace(item) {
+    const workspace = await gZenWorkspaces.createAndSaveWorkspace(
+      item.name,
+      undefined,
+      false,
+      0,
+      {
+        beforeChangeCallback: async newWorkspace => {
+          for (const child of item.items) {
+            if (child.type === "tab") {
+              const tab = this.#importTab(child, newWorkspace.uuid);
+              if (child.isPinned) {
+                gBrowser.pinTab(tab);
+              }
+              this.#placeTab(tab, newWorkspace.uuid, !!child.isPinned);
+            } else if (child.type === "folder") {
+              this.#importFolder(child, newWorkspace.uuid);
+            } else if (child.type === "splitView") {
+              this.#importSplitView(child, newWorkspace.uuid);
+            }
+          }
+        },
+      }
+    );
+    if (!workspace) {
+      return;
+    }
+    workspace.name = item.name;
+    const theme = item.theme;
+    if (theme) {
+      workspace.theme = nsZenThemePicker.getTheme(
+        theme.gradientColors.map(color => this.#importGradientColor(color))
+      );
+    }
+    gZenWorkspaces.saveWorkspace(workspace);
+    gZenThemePicker.onWorkspaceChange(workspace);
+    gZenStartup.playWindowSweepAnimation();
+  }
+
+  #importGradientColor(color) {
+    if (color.isCustom) {
+      const [r, g, b] = color.c;
+      return { ...color, c: `rgb(${r}, ${g}, ${b})` };
+    }
+    return color;
+  }
+
+  #importFolder(item, workspaceId, parentFolder = null) {
+    const folder = gZenFolders.createFolder([], {
+      label: item.name,
+      collapsed: true,
+      workspaceId,
+      insertAfter: parentFolder
+        ? parentFolder.groupContainer.lastElementChild
+        : null,
+    });
+    if (item.icon && FOLDER_ICON_RE.test(item.icon)) {
+      gZenFolders.setFolderUserIcon(folder, item.icon);
+    }
+    for (const child of item.items) {
+      if (child.type === "tab") {
+        const tab = this.#importTab(child, workspaceId);
+        gBrowser.pinTab(tab);
+        folder.addTabs([tab]);
+      } else if (child.type === "folder") {
+        this.#importFolder(child, workspaceId, folder);
+      } else if (child.type === "splitView") {
+        this.#importSplitView(child, workspaceId, folder);
+      }
+    }
+    return folder;
+  }
+
+  #importSplitView(item, workspaceId, folder = null) {
+    workspaceId ??= gZenWorkspaces.activeWorkspace;
+    const pinned = item.tabs.every(child => child.isPinned);
+    const tabs = item.tabs.map(child => {
+      const tab = this.#importTab(child, workspaceId);
+      if (folder) {
+        gBrowser.pinTab(tab);
+        folder.addTabs([tab]);
+      } else {
+        if (pinned) {
+          gBrowser.pinTab(tab);
+        }
+        this.#placeTab(tab, workspaceId, pinned);
+      }
+      return tab;
+    });
+    gZenViewSplitter.splitTabs(tabs, "grid", -1);
+  }
+
+  // Deterministic placement at the end of the right section;
+  // moveTabToWorkspace's anchor follows the new-tab-button position pref.
+  #placeTab(tab, workspaceId, pinned) {
+    const element = gZenWorkspaces.workspaceElement(workspaceId);
+    const container = pinned
+      ? element.pinnedTabsContainer
+      : element.tabsContainer;
+    const anchor = pinned
+      ? container.querySelector(".pinned-tabs-container-separator")
+      : container.querySelector("#tabbrowser-arrowscrollbox-periphery");
+    gBrowser.zenHandleTabMove(tab, () => {
+      tab.setAttribute("zen-workspace-id", workspaceId);
+      container.insertBefore(tab, anchor);
+    });
+  }
+
+  #importTab(item, workspaceId, { lazyBrowser = true } = {}) {
+    const tab = gBrowser.addTrustedTab(item.url, {
+      createLazyBrowser: lazyBrowser,
+      inBackground: true,
+      skipAnimation: true,
+      skipBackgroundNotify: true,
+      lazyTabTitle: item.label || undefined,
+      skipRoute: true,
+    });
+    if (workspaceId) {
+      tab.setAttribute("zen-workspace-id", workspaceId);
+    }
+    if (item.image && SHAREABLE_ICON_RE.test(item.image)) {
+      try {
+        gBrowser.setIcon(tab, item.image);
+        lazy.TabStateCache.update(tab.linkedBrowser.permanentKey, {
+          image: null,
+        });
+      } catch (e) {
+        console.error("ZenShare: could not set imported tab icon:", e);
+      }
+    }
+    return tab;
+  }
+}
+
+window.gZenShareManager = new nsZenShareManager();

src/zen/share/jar.inc.mn

@@ -0,0 +1,7 @@
+# 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/.
+
+*       content/browser/zen-styles/zen-share.css                                (../../zen/share/zen-share.css)
+*       content/browser/zen-components/windows/zen-share-confirm.xhtml          (../../zen/share/zen-share-confirm.inc.xhtml)
+        content/browser/zen-components/windows/zen-share-confirm.js             (../../zen/share/zen-share-confirm.js)

src/zen/share/moz.build

@@ -4,4 +4,6 @@
 
 EXTRA_JS_MODULES.zen.share += [
   "share.schema.json",
+  "ZenShareClient.sys.mjs",
+  "ZenShareManager.mjs",
 ]

src/zen/share/share.schema.json

@@ -7,11 +7,7 @@
       "type": "string"
     },
     "shared": {
-      "type": "array",
-      "minItems": 1,
-      "items": {
-        "$ref": "#/$defs/shareable"
-      }
+      "$ref": "#/$defs/shareable"
     }
   },
   "required": ["shared"],
@@ -22,21 +18,10 @@
       "oneOf": [
         { "$ref": "#/$defs/space" },
         { "$ref": "#/$defs/folder" },
-        { "$ref": "#/$defs/splitView" },
-        { "$ref": "#/$defs/gradientPreset" }
+        { "$ref": "#/$defs/splitView" }
       ]
     },
 
-    "gradientPreset": {
-      "type": "object",
-      "properties": {
-        "type": { "const": "gradientPreset" },
-        "theme": { "$ref": "#/$defs/theme" }
-      },
-      "required": ["type", "theme"],
-      "additionalProperties": false
-    },
-
     "space": {
       "type": "object",
       "properties": {
@@ -144,11 +129,19 @@
     },
 
     "spaceItem": {
-      "oneOf": [{ "$ref": "#/$defs/tab" }, { "$ref": "#/$defs/folder" }]
+      "oneOf": [
+        { "$ref": "#/$defs/tab" },
+        { "$ref": "#/$defs/folder" },
+        { "$ref": "#/$defs/splitView" }
+      ]
     },
 
     "folderItem": {
-      "oneOf": [{ "$ref": "#/$defs/tab" }, { "$ref": "#/$defs/folder" }]
+      "oneOf": [
+        { "$ref": "#/$defs/tab" },
+        { "$ref": "#/$defs/folder" },
+        { "$ref": "#/$defs/splitView" }
+      ]
     }
   }
 }

src/zen/share/zen-share-confirm.inc.xhtml

@@ -0,0 +1,60 @@
+#filter substitution
+<?xml version="1.0"?>
+
+# -*- Mode: HTML -*-
+#
+# 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/.
+
+<!DOCTYPE window>
+
+<window
+  xmlns:html="http://www.w3.org/1999/xhtml"
+  xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
+  id="zenShareConfirmDialog"
+>
+  <dialog
+    buttons="accept,cancel"
+    data-l10n-id="zen-share-confirm-dialog"
+    data-l10n-attrs="buttonlabelaccept"
+  >
+    <linkset>
+      <html:link
+        rel="stylesheet"
+        href="chrome://global/skin/global.css"
+        type="text/css"
+      />
+      <html:link
+        rel="stylesheet"
+        href="chrome://browser/content/zen-styles/zen-theme.css"
+        type="text/css"
+      />
+      <html:link rel="localization" href="browser/zen-share.ftl" />
+    </linkset>
+
+    <script src="chrome://browser/content/zen-components/windows/zen-share-confirm.js"></script>
+
+    <vbox style="padding-inline: 12px;">
+      <html:h2
+        data-l10n-id="zen-share-confirm-title"
+      ></html:h2>
+      <description data-l10n-id="zen-share-confirm-description" />
+      <description
+        style="margin: 12px 0 16px;"
+        data-l10n-id="zen-share-confirm-anonymous"
+      />
+      <html:input
+        style="margin-bottom: 12px;"
+        id="zen-share-confirm-name"
+        type="text"
+        maxlength="200"
+        data-l10n-id="zen-share-confirm-name-input"
+      />
+      <checkbox
+        id="zen-share-confirm-dont-ask"
+        data-l10n-id="zen-share-confirm-dont-ask"
+      />
+    </vbox>
+  </dialog>
+</window>

src/zen/share/zen-share-confirm.js

@@ -0,0 +1,27 @@
+/* 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/. */
+
+"use strict";
+
+{
+  const args = window.arguments?.[0] || {};
+
+  window.addEventListener(
+    "load",
+    () => {
+      const nameInput = document.getElementById("zen-share-confirm-name");
+      nameInput.value = args.name || "";
+      nameInput.focus();
+
+      document.addEventListener("dialogaccept", () => {
+        args.accepted = true;
+        args.name = nameInput.value.trim();
+        args.dontAsk = document.getElementById(
+          "zen-share-confirm-dont-ask"
+        ).checked;
+      });
+    },
+    { once: true }
+  );
+}

src/zen/share/zen-share.css

@@ -0,0 +1,259 @@
+/* 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-share-overlay {
+  position: absolute;
+  inset: 0;
+  z-index: 5;
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  justify-content: center;
+  gap: 28px;
+  padding: 32px;
+  background: var(--zen-transparent-browser-background);
+}
+
+browser[zen-share-overlay-showing] {
+  -moz-subtree-hidden-only-visually: 1;
+}
+
+.zen-share-overlay-card {
+  display: flex;
+  flex-direction: column;
+  width: 325px;
+  max-height: 76%;
+  border-radius: 30px;
+  background: var(--zen-dialog-background);
+  box-shadow:
+    0 1px 3px rgba(0, 0, 0, 0.07),
+    0 14px 40px -10px rgba(0, 0, 0, 0.28);
+  overflow: hidden;
+  animation: zen-share-overlay-enter 0.35s cubic-bezier(0.2, 0.8, 0.2, 1) both;
+}
+
+.zen-share-overlay-add {
+  min-width: 260px;
+  max-width: 100%;
+  padding: 16px 48px;
+  border-radius: 18px;
+  font-size: 1.1em;
+  animation: zen-share-overlay-enter 0.35s cubic-bezier(0.2, 0.8, 0.2, 1) 0.06s
+    both;
+
+  &[disabled] {
+    opacity: 0.5;
+    pointer-events: none;
+  }
+}
+
+@keyframes zen-share-overlay-enter {
+  from {
+    opacity: 0;
+    transform: translateY(14px) scale(0.98);
+  }
+}
+
+.zen-share-overlay-items {
+  display: flex;
+  flex-direction: column;
+  gap: 8px;
+  overflow-y: auto;
+  scrollbar-width: none;
+  padding: 22px 20px 16px;
+  mask-image: linear-gradient(
+    transparent,
+    black 24px,
+    black calc(100% - 20px),
+    transparent
+  );
+}
+
+.zen-share-overlay-row {
+  display: flex;
+  align-items: center;
+  gap: 14px;
+  padding: 10px 14px;
+  border-radius: 12px;
+  min-width: 0;
+
+  &:hover {
+    background: color-mix(in srgb, currentColor 7%, transparent);
+  }
+
+  &:active {
+    background: color-mix(in srgb, currentColor 11%, transparent);
+  }
+}
+
+.zen-share-overlay-row-icon {
+  width: 18px;
+  height: 18px;
+  flex-shrink: 0;
+  border-radius: 4px;
+}
+
+.zen-share-overlay-folder-icon {
+  width: 24px;
+  height: 24px;
+  flex-shrink: 0;
+  margin: -3px;
+
+%include ../folders/zen-folder-icon.inc.css
+
+  /* The dots stand in for the icon on active sidebar folders; the preview
+   * always shows the plain folder. */
+  & .dots {
+    opacity: 0;
+  }
+}
+
+.zen-share-overlay-row-label {
+  font-size: 1.1em;
+  font-weight: 500;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+
+.zen-share-overlay-split {
+  display: flex;
+  gap: 10px;
+  min-width: 0;
+
+  & .zen-share-overlay-row {
+    flex: 1 1 0;
+    padding: 6px 14px;
+    border-radius: 8px;
+  }
+
+  & .zen-share-overlay-row:not(:first-child) {
+    position: relative;
+
+    &::before {
+      content: "";
+      position: absolute;
+      inset-block: 6px;
+      inset-inline-start: -5.5px;
+      width: 1px;
+      background: var(--zen-colors-border);
+    }
+  }
+}
+
+.zen-share-overlay-children-clip {
+  display: grid;
+  grid-template-rows: 1fr;
+  transition: grid-template-rows 0.25s cubic-bezier(0.2, 0.8, 0.2, 1);
+}
+
+.zen-share-overlay-folder[collapsed] > .zen-share-overlay-children-clip {
+  grid-template-rows: 0fr;
+}
+
+.zen-share-overlay-children {
+  display: flex;
+  flex-direction: column;
+  gap: 8px;
+  margin-inline-start: 28px;
+  min-height: 0;
+  overflow: hidden;
+}
+
+.zen-share-overlay-status {
+  padding: 28px;
+  text-align: center;
+  opacity: 0.7;
+}
+
+.zen-share-overlay-footer {
+  position: relative;
+  isolation: isolate;
+  display: flex;
+  align-items: center;
+  margin-top: auto;
+  padding: 22px 20px 20px;
+  border-top: 2px dashed
+    color-mix(in srgb, var(--zen-primary-color) 22%, var(--zen-colors-border));
+  background: color-mix(
+    in srgb,
+    var(--zen-primary-color) 7%,
+    var(--zen-dialog-background)
+  );
+}
+
+.zen-share-overlay-badge-stack {
+  position: relative;
+  flex: 1;
+  min-width: 0;
+}
+
+.zen-share-overlay-badge {
+  position: relative;
+  z-index: 2;
+  display: flex;
+  align-items: center;
+  gap: 14px;
+  min-width: 0;
+  padding: 14px 18px;
+  border-radius: 18px;
+  border: 1px solid
+    light-dark(
+      color-mix(in srgb, currentColor 12%, var(--zen-colors-border)),
+      color-mix(in srgb, currentColor 8%, transparent)
+    );
+  background: light-dark(#ffffff, #1c1c1e);
+  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.07);
+}
+
+.zen-share-overlay-badge-sheet {
+  position: absolute;
+  height: 26px;
+  border-radius: 14px;
+  border: 1px solid
+    light-dark(
+      color-mix(in srgb, currentColor 12%, var(--zen-colors-border)),
+      color-mix(in srgb, currentColor 8%, transparent)
+    );
+  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.07);
+
+  &.first {
+    z-index: 1;
+    inset-inline: 10px;
+    top: -7px;
+    background: color-mix(in srgb, currentColor 2%, light-dark(#ffffff, #1c1c1e));
+  }
+
+  &.second {
+    z-index: 0;
+    inset-inline: 22px;
+    top: -13px;
+    background: color-mix(in srgb, currentColor 4%, light-dark(#ffffff, #1c1c1e));
+  }
+}
+
+.zen-share-overlay-badge-icon {
+  width: 26px;
+  height: 26px;
+  flex-shrink: 0;
+  -moz-context-properties: fill;
+  fill: color-mix(in srgb, var(--zen-accent-button-color) 60%, currentColor);
+}
+
+.zen-share-overlay-badge-text {
+  min-width: 0;
+  color: color-mix(in srgb, var(--zen-accent-button-color) 30%, currentColor);
+}
+
+.zen-share-overlay-badge-title {
+  font-weight: 600;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+
+.zen-share-overlay-badge-subtitle {
+  opacity: 0.6;
+  font-size: smaller;
+}

src/zen/spaces/ZenSpaceIcons.mjs

@@ -110,7 +110,7 @@ class nsZenWorkspaceIcons extends MozXULElement {
     button.setAttribute("zen-workspace-id", workspace.uuid);
     button.setAttribute("context", "zenWorkspaceMoreActions");
     const icon = document.createXULElement("label");
-    icon.setAttribute("class", "zen-workspace-icon");
+    icon.setAttribute("class", "zen-workspace-icon no-squircles");
     const isSvgIcon = workspace.icon && workspace.icon.endsWith(".svg");
     if (gZenWorkspaces.workspaceHasIcon(workspace)) {
       if (isSvgIcon) {

src/zen/spaces/ZenSpaceManager.mjs

@@ -432,8 +432,9 @@ class nsZenWorkspaces {
     // Set a hidden state if the essentials section is not supposed
     // to be shown on the current workspace, else remove the hidden state
     if (
-      this.containerSpecificEssentials &&
-      this.getActiveWorkspaceFromCache()?.containerTabId != container
+      this.activeWorkspace === this.creatingWorkspaceId ||
+      (this.containerSpecificEssentials &&
+        this.getActiveWorkspaceFromCache()?.containerTabId + 0 != container)
     ) {
       essentialsContainer.setAttribute("hidden", "true");
     } else {
@@ -872,7 +873,7 @@ class nsZenWorkspaces {
       ) {
         this.log(`Found tab to select: ${this._tabToSelect}, ${tabs.length}`);
         let tabToUse = gZenGlanceManager.getTabOrGlanceParent(
-          tabs[this._tabToSelect + 1] || this._emptyTab
+          tabs[this._tabToSelect] || this._emptyTab
         );
         gBrowser.selectedTab = tabToUse;
         this._removedByStartupPage = true;
@@ -2341,9 +2342,13 @@ class nsZenWorkspaces {
       )
     ) {
       tabToSelect = lastSelectedTab;
+    } else if (!onInit && !tabToSelect) {
+      // Create new tab if needed and no suitable tab was found
+      tabToSelect = this._emptyTab;
     }
     // Find first suitable tab
-    else {
+    // If we found a tab to select, select it
+    if (!tabToSelect || tabToSelect.closing) {
       tabToSelect = gBrowser.visibleTabs.find(tab => !tab.pinned);
       if (!tabToSelect && gBrowser.visibleTabs.length) {
         tabToSelect = gBrowser.visibleTabs[gBrowser.visibleTabs.length - 1];
@@ -2354,12 +2359,6 @@ class nsZenWorkspaces {
       }
     }
 
-    // If we found a tab to select, select it
-    if (!onInit && !tabToSelect) {
-      // Create new tab if needed and no suitable tab was found
-      const newTab = this.selectEmptyTab();
-      tabToSelect = newTab;
-    }
     if (tabToSelect && !onInit) {
       tabToSelect._visuallySelected = true;
     }
@@ -2890,6 +2889,12 @@ class nsZenWorkspaces {
     });
   }
 
+  contextShareWorkspace() {
+    const workspaceId =
+      this.#contextMenuData?.workspaceId || this.activeWorkspace;
+    gZenShareManager.shareSpace(workspaceId);
+  }
+
   async contextDeleteWorkspace() {
     const workspaceId =
       this.#contextMenuData?.workspaceId || this.activeWorkspace;
@@ -2906,7 +2911,10 @@ class nsZenWorkspaces {
   }
 
   findTabToBlur(tab) {
-    if ((!this._shouldChangeToTab(tab) || !tab) && this._emptyTab) {
+    if (
+      (!tab || !this._shouldChangeToTab(tab) || !gBrowser.tabs.includes(tab)) &&
+      this._emptyTab
+    ) {
       return this._emptyTab;
     }
     return tab;
@@ -3283,7 +3291,7 @@ class nsZenWorkspaces {
     if (!(!event || event.target === window)) {
       return;
     }
-    gZenUIManager.updateTabsToolbar();
+    gZenUIManager.updateTabsToolbar(!!event);
     // Check if workspace icons overflow the parent container
     let parent = this.workspaceIcons;
     if (!parent || this._processingResize) {

src/zen/spaces/zen-workspaces.css

@@ -30,9 +30,9 @@
 
   & toolbarbutton {
     margin: 0;
-    max-width: 28px;
+    max-width: 30px;
     border-radius: var(--toolbarbutton-border-radius);
-    height: 28px;
+    height: 30px;
     display: flex;
     justify-content: center;
     padding: 0 !important;
@@ -58,8 +58,8 @@
       }
 
       &[no-icon='true'] {
-        width: 6px;
-        height: 6px;
+        width: 8px;
+        height: 8px;
         background: light-dark(rgba(0, 0, 0, 0.4), rgba(255, 255, 255, 0.4));
         border-radius: 50%;
       }
@@ -329,7 +329,6 @@ zen-workspace {
     color-mix(in srgb, rgba(255, 255, 255, 0.18) 95%, var(--zen-primary-color))
   ) !important;
   --tab-box-shadow-selected: 0 0.8px 1.5px 0px light-dark(rgba(0, 0, 0, 0.15), rgba(0, 0, 0, 0.05)) !important;
-  --tab-selected-textcolor: color-mix(in srgb, var(--toolbox-textcolor) 95%, var(--zen-primary-color)) !important;
 
   @media not (prefers-reduced-motion: reduce) {
     transition: padding-top 0.1s;
@@ -405,6 +404,7 @@ zen-workspace {
 
   :root:not(:is([animating-background], [swipe-gesture])) #navigator-toolbox:not([movingtab]) &:not([active]) {
     -moz-subtree-hidden-only-visually: 1;
+    content-visibility: hidden;
   }
 }
 

src/zen/split-view/ZenViewSplitter.mjs

@@ -336,7 +336,9 @@ class nsZenViewSplitter extends nsZenDOMOperatedFeature {
       if (
         !gBrowser.isTab(draggedTab) ||
         gBrowser.selectedTab.hasAttribute("zen-empty-tab") ||
-        draggedTab.documentGlobal !== window
+        draggedTab.documentGlobal !== window ||
+        // See gh-15329.
+        draggedTab.multiselected
       ) {
         return;
       }
@@ -1184,6 +1186,8 @@ class nsZenViewSplitter extends nsZenDOMOperatedFeature {
     document.l10n.setAttributes(splitTabCommand, "tab-zen-split-tabs", {
       tabCount: isExistingSplitView ? -1 : selectedTabs.length,
     });
+    document.getElementById("context_zenShareSplitView").hidden =
+      !gZenShareManager.enabled || !isExistingSplitView;
     if (isExistingSplitView) {
       splitTabCommand.removeAttribute("hidden");
       return;
@@ -1204,6 +1208,10 @@ class nsZenViewSplitter extends nsZenDOMOperatedFeature {
                 data-lazy-l10n-id="tab-zen-split-tabs"
                 data-l10n-args='{"tabCount": 1}'
                 command="cmd_zenSplitViewContextMenu"/>
+      <menuitem id="context_zenShareSplitView"
+                data-lazy-l10n-id="zen-share-split-view"
+                hidden="true"
+                command="cmd_zenCtxShareSplitView"/>
     `);
     document.getElementById("context_moveTabToSplitView").before(element);
   }
@@ -1252,6 +1260,16 @@ class nsZenViewSplitter extends nsZenDOMOperatedFeature {
     this.splitTabs([currentTab, newTab], undefined, 1);
   }
 
+  /**
+   * Shares the split view of the context tab.
+   */
+  contextShareSplitView() {
+    const group = TabContextMenu.contextTab?.group;
+    if (group?.hasAttribute("split-view-group")) {
+      gZenShareManager.shareSplitView(group);
+    }
+  }
+
   /**
    * Splits the selected tabs.
    *

src/zen/sync/ZenSpacesSync.sys.mjs

@@ -75,10 +75,9 @@ class ZenSpacesSyncStore extends Store {
 }
 
 /**
- * Tracker for the Spaces engine. There is no per-event bookkeeping: every
- * time fresh sidebar data is collected (or a container changes), the model
- * diffs the current projections against the last-uploaded snapshot; the
- * score is only bumped when something actually differs.
+ * Tracker for the Spaces engine. The model diffs the current projections
+ * against the last-uploaded snapshot. The score is only bumped when
+ * something actually differs.
  */
 class ZenSpacesSyncTracker extends Tracker {
   _ignoreAll = false;

src/zen/sync/ZenSpacesSyncApplier.sys.mjs

@@ -11,10 +11,20 @@ import {
   ZenSpacesSyncModel,
 } from "resource:///modules/zen/ZenSpacesSyncModel.sys.mjs";
 
+import { XPCOMUtils } from "resource://gre/modules/XPCOMUtils.sys.mjs";
+
 const lazy = {};
 
+XPCOMUtils.defineLazyPreferenceGetter(
+  lazy,
+  "syncNormalTabs",
+  "zen.spaces-sync.normal-tabs",
+  false
+);
+
 ChromeUtils.defineESModuleGetters(lazy, {
   SessionSaver: "resource:///modules/sessionstore/SessionSaver.sys.mjs",
+  SessionStore: "resource:///modules/sessionstore/SessionStore.sys.mjs",
   E10SUtils: "resource://gre/modules/E10SUtils.sys.mjs",
   TabStateCache: "resource:///modules/sessionstore/TabStateCache.sys.mjs",
   ZenWindowSync: "resource:///modules/zen/ZenWindowSync.sys.mjs",
@@ -84,6 +94,11 @@ class nsZenSpacesSyncApplier {
       if (!data) {
         continue;
       }
+      if (data.pinned === false && !lazy.syncNormalTabs) {
+        // Normal-tab syncing is off here: leave the record untouched and
+        // unacknowledged, like an unknown kind.
+        continue;
+      }
       const entry = { key: record.id, data, record };
       switch (record.cleartext.kind) {
         case RECORD_KINDS.CONTAINER:
@@ -141,6 +156,7 @@ class nsZenSpacesSyncApplier {
         fail(entry.record, noWindow);
       }
     } else {
+      await lazy.SessionStore.promiseAllWindowsRestored;
       await win.gZenWorkspaces.promiseInitialized;
       this.#maybePlayFirstSyncAnimation(win);
       // A sync apply is a materialization just like session restore,
@@ -510,9 +526,6 @@ class nsZenSpacesSyncApplier {
         if (!folder?.isZenFolder) {
           continue;
         }
-        // Members without their own tombstone survive: unpack, then delete
-        // the (now empty) folder.
-        await folder.unpackTabs();
         await folder.delete();
       } catch (e) {
         fail(record, e);
@@ -567,7 +580,9 @@ class nsZenSpacesSyncApplier {
       if (data.workspaceUuid) {
         tab.setAttribute("zen-workspace-id", data.workspaceUuid);
       }
-      win.gBrowser.pinTab(tab);
+      if (data.pinned !== false) {
+        win.gBrowser.pinTab(tab);
+      }
       if (data.workspaceUuid) {
         win.gZenWorkspaces.moveTabToWorkspace(tab, data.workspaceUuid);
       }
@@ -593,7 +608,10 @@ class nsZenSpacesSyncApplier {
     const identityChanged =
       initial?.entry?.url !== data.url ||
       (initial?.entry?.title || "") !== (data.title || "");
-    if (identityChanged || syncableIconUrl(initial?.image || "") !== icon) {
+    if (
+      data.pinned !== false &&
+      (identityChanged || syncableIconUrl(initial?.image || "") !== icon)
+    ) {
       lazy.ZenWindowSync.setPinnedInitialState(
         tab,
         { url: data.url, title: data.title || "" },
@@ -633,7 +651,7 @@ class nsZenSpacesSyncApplier {
         );
         win.gBrowser.setIcon(tab, icon);
         lazy.TabStateCache.update(tab.linkedBrowser.permanentKey, {
-          image: null,
+          image: icon || null,
         });
       } catch (e) {
         console.error("ZenSpacesSync: failed to set tab icon", e);
@@ -745,6 +763,17 @@ class nsZenSpacesSyncApplier {
       // The split record governs placement of its members.
       return;
     }
+    const wantPinned = data.pinned !== false;
+    if (wantPinned !== tab.pinned) {
+      if (wantPinned) {
+        win.gBrowser.pinTab(tab);
+      } else {
+        win.gBrowser.unpinTab(tab);
+        // Pin identity would otherwise freeze the projection of what is now
+        // a normal tab.
+        delete tab._zenPinnedInitialState;
+      }
+    }
     this.#applyFolderMembership(win, tab, data.folderId);
     if (
       !data.folderId &&

src/zen/sync/ZenSpacesSyncModel.sys.mjs

@@ -22,6 +22,13 @@ XPCOMUtils.defineLazyPreferenceGetter(
   false
 );
 
+XPCOMUtils.defineLazyPreferenceGetter(
+  lazy,
+  "syncNormalTabs",
+  "zen.spaces-sync.normal-tabs",
+  false
+);
+
 /**
  * Debug logging for the whole Spaces sync pipeline.
  *
@@ -258,19 +265,31 @@ class nsZenSpacesSyncModel {
 
   /* Mark: projections */
 
-  #isSyncableTab(tabData) {
+  #isTabRecordMaterial(tabData) {
     return !!(
       tabData &&
       tabData.zenSyncId &&
-      (tabData.pinned || tabData.zenEssential) &&
       !tabData.zenIsEmpty &&
       !tabData.zenIsGlance &&
       !tabData.zenLiveFolderItemId
     );
   }
 
+  #isSyncableTab(tabData) {
+    return (
+      this.#isTabRecordMaterial(tabData) &&
+      (!!tabData.pinned || !!tabData.zenEssential || lazy.syncNormalTabs)
+    );
+  }
+
   #tabIdentity(tabData) {
-    const initial = tabData._zenPinnedInitialState;
+    // Pin identity freezes url/title at pin time. A normal tab's identity
+    // follows its live entry (a leftover initial state from a past pin must
+    // not shadow it).
+    const initial =
+      tabData.pinned || tabData.zenEssential
+        ? tabData._zenPinnedInitialState
+        : null;
     let url = initial?.entry?.url;
     let title = initial?.entry?.title;
     if (!url || url === "about:blank") {
@@ -473,6 +492,7 @@ class nsZenSpacesSyncModel {
             create: true,
           }),
           essential,
+          pinned: !!(tab.pinned || tab.zenEssential),
           workspaceUuid: essential ? null : tab.zenWorkspace || null,
           folderId: ctx.folderOf(tab.groupId || null),
           staticLabel:
@@ -494,8 +514,52 @@ class nsZenSpacesSyncModel {
     const map = new Map();
     const pending = new Set();
     const ctx = this.#projectionContext(sidebar);
-    const { tabs, folders, splits, splitParents, splitWs } = ctx;
+    const spaces = sidebar.spaces || [];
 
+    this.#collectHeldIds(ctx, sidebar, pending);
+    this.#projectContainers(map);
+    this.#projectSpaces(map, ctx, spaces);
+    this.#projectFolders(map, ctx, pending);
+    this.#projectTabs(map, ctx);
+    this.#projectSplits(map, ctx);
+    this.#projectLayout(map, ctx, spaces);
+
+    this.#cache = { stamp, map, pending };
+    return map;
+  }
+
+  /**
+   * Items excluded only by the normal-tabs option are held back, not
+   * deleted. Flipping the option off must not tombstone them remotely.
+   *
+   * @param {object} ctx - The projection context.
+   * @param {object} sidebar - The collected sidebar data.
+   * @param {Set<string>} pending - Receives the held-back ids.
+   */
+  #collectHeldIds(ctx, sidebar, pending) {
+    if (lazy.syncNormalTabs) {
+      return;
+    }
+    const held = new Set();
+    for (const tab of ctx.allTabs) {
+      if (this.#isTabRecordMaterial(tab) && !this.#isSyncableTab(tab)) {
+        held.add(tab.zenSyncId);
+        pending.add(tab.zenSyncId);
+      }
+    }
+    for (const split of sidebar.splitViewData || []) {
+      if (
+        split?.groupId &&
+        !ctx.splitIds.has(split.groupId) &&
+        Array.isArray(split.tabs) &&
+        split.tabs.some(id => held.has(id))
+      ) {
+        pending.add(split.groupId);
+      }
+    }
+  }
+
+  #projectContainers(map) {
     for (const identity of lazy.ContextualIdentityService.getPublicIdentities()) {
       if (!identity.name) {
         continue;
@@ -516,8 +580,9 @@ class nsZenSpacesSyncModel {
         },
       });
     }
+  }
 
-    const spaces = sidebar.spaces || [];
+  #projectSpaces(map, ctx, spaces) {
     for (const space of spaces) {
       if (!space?.uuid) {
         continue;
@@ -537,8 +602,10 @@ class nsZenSpacesSyncModel {
         },
       });
     }
+  }
 
-    for (const folder of folders) {
+  #projectFolders(map, ctx, pending) {
+    for (const folder of ctx.folders) {
       const fid = folder.id;
       let live = null;
       if (folder.isLiveFolder) {
@@ -565,44 +632,46 @@ class nsZenSpacesSyncModel {
         },
       });
     }
+  }
 
-    this.#projectTabs(map, ctx);
-
-    for (const split of splits) {
+  #projectSplits(map, ctx) {
+    const tabById = new Map(ctx.tabs.map(t => [t.zenSyncId, t]));
+    for (const split of ctx.splits) {
+      const member = tabById.get(split.tabs[0]);
       map.set(split.groupId, {
         kind: RECORD_KINDS.SPLIT,
         data: {
           splitId: split.groupId,
           gridType: split.gridType || "grid",
+          pinned: !!(member?.pinned || member?.zenEssential),
           tabs: [...split.tabs],
-          workspaceUuid: splitWs.get(split.groupId) ?? null,
-          folderId: splitParents.get(split.groupId) || null,
+          workspaceUuid: ctx.splitWs.get(split.groupId) ?? null,
+          folderId: ctx.splitParents.get(split.groupId) || null,
         },
       });
     }
+  }
 
-    if (spaces.length) {
-      const essentials = {};
-      for (const tab of tabs) {
-        if (!tab.zenEssential) {
-          continue;
-        }
-        const key =
-          this.guidForContextId(tab.userContextId, { create: true }) ||
-          "default";
-        (essentials[key] ||= []).push(tab.zenSyncId);
+  #projectLayout(map, ctx, spaces) {
+    if (!spaces.length) {
+      return;
+    }
+    const essentials = {};
+    for (const tab of ctx.tabs) {
+      if (!tab.zenEssential) {
+        continue;
       }
-      map.set(LAYOUT_RECORD_ID, {
-        kind: RECORD_KINDS.LAYOUT,
-        data: {
-          spaces: spaces.map(s => s.uuid).filter(Boolean),
-          essentials,
-        },
-      });
+      const key =
+        this.guidForContextId(tab.userContextId, { create: true }) || "default";
+      (essentials[key] ||= []).push(tab.zenSyncId);
     }
-
-    this.#cache = { stamp, map, pending };
-    return map;
+    map.set(LAYOUT_RECORD_ID, {
+      kind: RECORD_KINDS.LAYOUT,
+      data: {
+        spaces: spaces.map(s => s.uuid).filter(Boolean),
+        essentials,
+      },
+    });
   }
 
   /**

src/zen/tabs/ZenPinnedTabManager.mjs

@@ -356,7 +356,7 @@ class nsZenPinnedTabManager extends nsZenDOMOperatedFeature {
         alwaysUnload &&
         ["close", "reset", "switch", "reset-switch"].includes(behavior)
       ) {
-        behavior = behavior.contains("reset")
+        behavior = behavior.includes("reset")
           ? "reset-unload-switch"
           : "unload-switch";
       }
@@ -680,7 +680,7 @@ class nsZenPinnedTabManager extends nsZenDOMOperatedFeature {
             }
             gBrowser.setIcon(tab, icon);
             lazy.TabStateCache.update(tab.permanentKey, {
-              image: null,
+              image: icon || null,
             });
           },
         });

src/zen/tabs/zen-tabs/vertical-tabs.css

@@ -1059,7 +1059,6 @@
 
 #tabs-newtab-button {
   display: none;
-  font-weight: 500;
   -moz-user-focus: ignore !important;
 }
 
@@ -1342,7 +1341,7 @@
   }
 }
 
-#tabs-newtab-button:not([in-urlbar="true"]) label,
+#tabs-newtab-button:not([in-urlbar="true"]),
 .zen-current-workspace-indicator-name {
   color: color-mix(in srgb, currentColor 70%, transparent);
 }

src/zen/tests/container_essentials/browser_container_specific_essentials.js

@@ -46,3 +46,38 @@ add_task(async function test_Check_Creation() {
 
   await gZenWorkspaces.removeWorkspace(newWorkspaceUUID);
 });
+
+add_task(async function test_Essentials_Hidden_Workspace_Creation() {
+  const originalWorkspace = gZenWorkspaces.getActiveWorkspace();
+
+  const essentialTab = BrowserTestUtils.addTab(gBrowser, "about:blank", {
+    skipAnimation: true,
+    userContextId: 0,
+  });
+  gZenPinnedTabManager.addToEssentials(essentialTab);
+  const essentialsContainer = essentialTab.parentNode;
+
+  await gZenWorkspaces.createAndSaveWorkspace(
+    "Empty Container Workspace",
+    undefined,
+    false,
+    1
+  );
+  const emptyWorkspace = gZenWorkspaces.getActiveWorkspace();
+
+  // The temporary creation workspace uses container 0, which previously
+  // caused the container 0 Essentials to reappear over the form.
+  await gZenWorkspaces.openWorkspaceCreation();
+
+  const creationForm = document.querySelector("zen-workspace-creation");
+  ok(creationForm, "Workspace creation form is shown");
+  ok(
+    BrowserTestUtils.isHidden(essentialsContainer),
+    "Essentials remain hidden while creating a workspace"
+  );
+
+  await creationForm.onCancelButtonCommand();
+  await gZenWorkspaces.changeWorkspace(originalWorkspace);
+  await gZenWorkspaces.removeWorkspace(emptyWorkspace.uuid);
+  await BrowserTestUtils.removeTab(essentialTab);
+});

src/zen/tests/device_sync/browser.toml

@@ -0,0 +1,19 @@
+# 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/.
+
+[DEFAULT]
+prefs = [
+  "zen.window-sync.enabled=true",
+  "zen.urlbar.replace-newtab=false",
+  "zen.spaces-sync.first-sync-animation-shown=true",
+]
+support-files = [
+  "head.js",
+]
+
+["browser_folder_delete.js"]
+
+["browser_normal_tabs_apply.js"]
+
+["browser_normal_tabs_projection.js"]

src/zen/tests/device_sync/browser_folder_delete.js

@@ -0,0 +1,100 @@
+/* Any copyright is dedicated to the Public Domain.
+   https://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+async function applyFolderWithMembers(fid, memberIds) {
+  const failed = await ZenSpacesSyncApplier.applyBatch([
+    folderRecord(fid),
+    ...memberIds.map(id => tabRecord(id, { pinned: true, folderId: fid })),
+  ]);
+  Assert.deepEqual(failed, [], "The folder batch should apply cleanly");
+  const folder = document.getElementById(fid);
+  Assert.ok(folder?.isZenFolder, "The folder should materialize");
+  for (const id of memberIds) {
+    Assert.equal(
+      document.getElementById(id)?.group,
+      folder,
+      `member ${id} should live in the folder`
+    );
+  }
+}
+
+add_task(async function test_FolderTombstoneWithMemberTombstones() {
+  await gZenWorkspaces.promiseInitialized;
+  const fid = "test-sync-del-a-folder";
+  const members = ["test-sync-del-a-1", "test-sync-del-a-2"];
+  await applyFolderWithMembers(fid, members);
+
+  const failed = await ZenSpacesSyncApplier.applyBatch([
+    tombstone(fid),
+    ...members.map(tombstone),
+  ]);
+  Assert.deepEqual(failed, [], "The tombstone batch should apply cleanly");
+  await TestUtils.waitForCondition(
+    () => !document.getElementById(fid),
+    "waiting for the folder to be removed"
+  );
+  for (const id of members) {
+    Assert.ok(!document.getElementById(id), `member ${id} should be gone`);
+  }
+
+  for (const id of [fid, ...members]) {
+    ZenSpacesSyncModel.noteApplied(id, null);
+  }
+});
+
+add_task(async function test_FolderTombstoneAloneDeletesMembers() {
+  await gZenWorkspaces.promiseInitialized;
+  const fid = "test-sync-del-b-folder";
+  const members = ["test-sync-del-b-1", "test-sync-del-b-2"];
+  await applyFolderWithMembers(fid, members);
+
+  const failed = await ZenSpacesSyncApplier.applyBatch([tombstone(fid)]);
+  Assert.deepEqual(failed, [], "The tombstone batch should apply cleanly");
+  await TestUtils.waitForCondition(
+    () => !document.getElementById(fid),
+    "waiting for the folder to be removed"
+  );
+  for (const id of members) {
+    const tab = document.getElementById(id);
+    Assert.ok(!tab, `member ${id} should be deleted, not orphaned as pinned`);
+  }
+
+  for (const id of [fid, ...members]) {
+    ZenSpacesSyncModel.noteApplied(id, null);
+  }
+});
+
+add_task(async function test_MemberMovedOutSurvivesFolderTombstone() {
+  await gZenWorkspaces.promiseInitialized;
+  const fid = "test-sync-del-c-folder";
+  const stays = "test-sync-del-c-stays";
+  const moved = "test-sync-del-c-moved";
+  await applyFolderWithMembers(fid, [stays, moved]);
+
+  const failed = await ZenSpacesSyncApplier.applyBatch([
+    tabRecord(moved, { pinned: true, folderId: null }),
+    tombstone(fid),
+  ]);
+  Assert.deepEqual(failed, [], "The batch should apply cleanly");
+  await TestUtils.waitForCondition(
+    () => !document.getElementById(fid),
+    "waiting for the folder to be removed"
+  );
+  const movedTab = document.getElementById(moved);
+  Assert.ok(movedTab, "the moved-out member should survive");
+  Assert.ok(!movedTab.group?.isZenFolder, "and no longer be in a folder");
+  Assert.ok(
+    !document.getElementById(stays),
+    "the member with no surviving record should be deleted"
+  );
+
+  ZenSpacesSyncModel.noteApplied(moved, null);
+  for (const id of [fid, stays]) {
+    ZenSpacesSyncModel.noteApplied(id, null);
+  }
+  if (movedTab) {
+    BrowserTestUtils.removeTab(movedTab);
+  }
+});

src/zen/tests/device_sync/browser_normal_tabs_apply.js

@@ -0,0 +1,129 @@
+/* Any copyright is dedicated to the Public Domain.
+   https://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+add_task(async function test_ApplySkippedWhileOptionOff() {
+  await gZenWorkspaces.promiseInitialized;
+  const id = "test-spaces-sync-normal-off";
+  const failed = await ZenSpacesSyncApplier.applyBatch([
+    tabRecord(id, { pinned: false }),
+  ]);
+  Assert.deepEqual(
+    failed,
+    [],
+    "A skipped normal-tab record should not be reported as failed"
+  );
+  Assert.ok(
+    !document.getElementById(id),
+    "No tab should materialize while the option is off"
+  );
+});
+
+add_task(async function test_ApplyCreatesUnpinnedTab() {
+  await SpecialPowers.pushPrefEnv({ set: [[NORMAL_TABS_PREF, true]] });
+  const id = "test-spaces-sync-normal-on";
+  const failed = await ZenSpacesSyncApplier.applyBatch([
+    tabRecord(id, { pinned: false }),
+  ]);
+  Assert.deepEqual(failed, [], "The record should apply cleanly");
+
+  const tab = document.getElementById(id);
+  Assert.ok(gBrowser.isTab(tab), "The tab should materialize");
+  Assert.ok(!tab.pinned, "The tab should not be pinned");
+  Assert.equal(
+    tab.getAttribute("zen-workspace-id"),
+    gZenWorkspaces.activeWorkspace,
+    "The tab should land in the record's workspace"
+  );
+  Assert.ok(
+    !tab._zenPinnedInitialState,
+    "A normal tab should carry no pin identity"
+  );
+
+  ZenSpacesSyncModel.noteApplied(id, null);
+  BrowserTestUtils.removeTab(tab);
+  await SpecialPowers.popPrefEnv();
+});
+
+add_task(async function test_UpdateRetargetsUnloadedNormalTab() {
+  await SpecialPowers.pushPrefEnv({ set: [[NORMAL_TABS_PREF, true]] });
+  const id = "test-spaces-sync-retarget";
+  let failed = await ZenSpacesSyncApplier.applyBatch([
+    tabRecord(id, { pinned: false, url: "https://example.com/first" }),
+  ]);
+  Assert.deepEqual(failed, [], "The record should apply cleanly");
+  const tab = document.getElementById(id);
+  Assert.ok(!tab.linkedPanel, "The synced tab should stay unloaded");
+
+  failed = await ZenSpacesSyncApplier.applyBatch([
+    tabRecord(id, { pinned: false, url: "https://example.com/second" }),
+  ]);
+  Assert.deepEqual(failed, [], "The navigation record should apply cleanly");
+  Assert.ok(!tab.linkedPanel, "The tab should stay unloaded after retarget");
+  const state = JSON.parse(SessionStore.getTabState(tab));
+  Assert.equal(
+    state.entries.at(-1)?.url,
+    "https://example.com/second",
+    "The unloaded tab's state should point at the new url"
+  );
+
+  ZenSpacesSyncModel.noteApplied(id, null);
+  BrowserTestUtils.removeTab(tab);
+  await SpecialPowers.popPrefEnv();
+});
+
+add_task(async function test_UpdateRetargetsDiscardedNormalTab() {
+  await SpecialPowers.pushPrefEnv({ set: [[NORMAL_TABS_PREF, true]] });
+  const tab = await openSyncableTab("https://example.com/?loadedfirst");
+  const id = tab.id;
+  await BrowserTestUtils.switchTab(gBrowser, gBrowser.tabs[0]);
+  gBrowser.discardBrowser(tab);
+  Assert.ok(!tab.linkedPanel, "The tab should be discarded");
+
+  const failed = await ZenSpacesSyncApplier.applyBatch([
+    tabRecord(id, { pinned: false, url: "https://example.com/?remotenav" }),
+  ]);
+  Assert.deepEqual(failed, [], "The navigation record should apply cleanly");
+  Assert.ok(!tab.linkedPanel, "The tab should stay unloaded after retarget");
+  const state = JSON.parse(SessionStore.getTabState(tab));
+  Assert.equal(
+    state.entries.at(-1)?.url,
+    "https://example.com/?remotenav",
+    "The discarded tab's state should point at the new url"
+  );
+
+  ZenSpacesSyncModel.noteApplied(id, null);
+  BrowserTestUtils.removeTab(tab);
+  await SpecialPowers.popPrefEnv();
+});
+
+add_task(async function test_ApplyPinStateTransition() {
+  await SpecialPowers.pushPrefEnv({ set: [[NORMAL_TABS_PREF, true]] });
+  const id = "test-spaces-sync-transition";
+  let failed = await ZenSpacesSyncApplier.applyBatch([
+    tabRecord(id, { pinned: true }),
+  ]);
+  Assert.deepEqual(failed, [], "The pinned record should apply cleanly");
+  const tab = document.getElementById(id);
+  Assert.ok(gBrowser.isTab(tab), "The tab should materialize");
+  Assert.ok(tab.pinned, "A pinned record should materialize pinned");
+  await TestUtils.waitForCondition(
+    () => tab._zenPinnedInitialState,
+    "waiting for the pin identity to settle"
+  );
+
+  failed = await ZenSpacesSyncApplier.applyBatch([
+    tabRecord(id, { pinned: false }),
+  ]);
+  Assert.deepEqual(failed, [], "The demoting record should apply cleanly");
+  Assert.ok(!tab.pinned, "A record demotion should unpin the tab");
+  Assert.ok(
+    !tab._zenPinnedInitialState,
+    "Demotion should clear the pin identity"
+  );
+
+  ZenSpacesSyncModel.noteApplied(id, null);
+  BrowserTestUtils.removeTab(tab);
+  await SpecialPowers.popPrefEnv();
+});

src/zen/tests/device_sync/browser_normal_tabs_projection.js

@@ -0,0 +1,81 @@
+/* Any copyright is dedicated to the Public Domain.
+   https://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+add_task(async function test_ProjectionGatedByPref() {
+  await gZenWorkspaces.promiseInitialized;
+  const pinnedTab = await openSyncableTab("https://example.com/?pinned", {
+    pinned: true,
+  });
+  const normalTab = await openSyncableTab("https://example.com/?normal");
+
+  let projections = await collectProjections();
+  const pinnedRecord = projections.get(pinnedTab.id);
+  Assert.ok(pinnedRecord, "Pinned tab should project with the option off");
+  Assert.equal(
+    pinnedRecord.data.pinned,
+    true,
+    "Pinned tab record should carry pinned: true"
+  );
+  Assert.ok(
+    !projections.get(normalTab.id),
+    "Normal tab should not project with the option off"
+  );
+
+  await SpecialPowers.pushPrefEnv({ set: [[NORMAL_TABS_PREF, true]] });
+  ZenSpacesSyncModel.invalidate();
+  projections = ZenSpacesSyncModel.projections();
+
+  const record = projections.get(normalTab.id);
+  Assert.ok(record, "Normal tab should project with the option on");
+  Assert.equal(
+    record.data.pinned,
+    false,
+    "Normal tab record should carry pinned: false"
+  );
+  Assert.equal(
+    record.data.workspaceUuid,
+    gZenWorkspaces.activeWorkspace,
+    "Normal tab record should name its workspace"
+  );
+  const space = projections.get(gZenWorkspaces.activeWorkspace);
+  Assert.ok(
+    space?.data?.children?.includes(normalTab.id),
+    "The space's child order should include the normal tab"
+  );
+
+  await SpecialPowers.popPrefEnv();
+  BrowserTestUtils.removeTab(normalTab);
+  BrowserTestUtils.removeTab(pinnedTab);
+});
+
+add_task(async function test_DisablingOptionHoldsBackInsteadOfTombstoning() {
+  await gZenWorkspaces.promiseInitialized;
+  await SpecialPowers.pushPrefEnv({ set: [[NORMAL_TABS_PREF, true]] });
+  const normalTab = await openSyncableTab("https://example.com/?heldback");
+
+  await collectProjections();
+  ZenSpacesSyncModel.markUploaded([normalTab.id]);
+  let changes = ZenSpacesSyncModel.computeChangedIDs();
+  Assert.ok(
+    !(normalTab.id in changes),
+    "An uploaded normal tab should report no pending change"
+  );
+
+  await SpecialPowers.popPrefEnv();
+  ZenSpacesSyncModel.invalidate();
+  Assert.ok(
+    !ZenSpacesSyncModel.projections().get(normalTab.id),
+    "Normal tab should stop projecting once the option is off"
+  );
+  changes = ZenSpacesSyncModel.computeChangedIDs();
+  Assert.ok(
+    !(normalTab.id in changes),
+    "Disabling the option should not tombstone the tab"
+  );
+
+  // Drop the snapshot entry so this task leaves no sync state behind.
+  ZenSpacesSyncModel.noteApplied(normalTab.id, null);
+  BrowserTestUtils.removeTab(normalTab);
+});

src/zen/tests/device_sync/head.js

@@ -0,0 +1,108 @@
+/* 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/. */
+
+"use strict";
+
+const { ZenSpacesSyncModel } = ChromeUtils.importESModule(
+  "resource:///modules/zen/ZenSpacesSyncModel.sys.mjs"
+);
+const { ZenSpacesSyncApplier } = ChromeUtils.importESModule(
+  "resource:///modules/zen/ZenSpacesSyncApplier.sys.mjs"
+);
+const { SessionSaver } = ChromeUtils.importESModule(
+  "resource:///modules/sessionstore/SessionSaver.sys.mjs"
+);
+const { TabStateFlusher } = ChromeUtils.importESModule(
+  "resource:///modules/sessionstore/TabStateFlusher.sys.mjs"
+);
+const { TestUtils } = ChromeUtils.importESModule(
+  "resource://testing-common/TestUtils.sys.mjs"
+);
+const { E10SUtils } = ChromeUtils.importESModule(
+  "resource://gre/modules/E10SUtils.sys.mjs"
+);
+const { PromiseTestUtils } = ChromeUtils.importESModule(
+  "resource://testing-common/PromiseTestUtils.sys.mjs"
+);
+
+PromiseTestUtils.allowMatchingRejectionsGlobally(/menu-bookmark-tab/);
+
+const NORMAL_TABS_PREF = "zen.spaces-sync.normal-tabs";
+
+/**
+ * Runs a full session save (which collects the sidebar data) and returns
+ * fresh sync projections built from it.
+ */
+async function collectProjections() {
+  await SessionSaver.run();
+  ZenSpacesSyncModel.invalidate();
+  return ZenSpacesSyncModel.projections();
+}
+
+async function openSyncableTab(url, { pinned = false } = {}) {
+  const tab = await BrowserTestUtils.openNewForegroundTab(gBrowser, url);
+  if (pinned) {
+    gBrowser.pinTab(tab);
+  }
+  await TabStateFlusher.flush(tab.linkedBrowser);
+  ok(tab.id, "the tab should have a sync id");
+  return tab;
+}
+
+function tabRecord(
+  id,
+  {
+    pinned,
+    url = "https://example.com/",
+    current = null,
+    workspaceUuid,
+    folderId = null,
+  } = {}
+) {
+  return {
+    id,
+    deleted: false,
+    cleartext: {
+      kind: "tab",
+      data: {
+        tabId: id,
+        url,
+        title: "Synced tab",
+        current,
+        icon: null,
+        containerGuid: null,
+        essential: false,
+        pinned,
+        workspaceUuid: workspaceUuid ?? gZenWorkspaces.activeWorkspace,
+        folderId,
+        staticLabel: null,
+        hasStaticIcon: false,
+        defaultContainer: false,
+      },
+    },
+  };
+}
+
+function folderRecord(id, { name = "Synced folder", workspaceUuid } = {}) {
+  return {
+    id,
+    deleted: false,
+    cleartext: {
+      kind: "folder",
+      data: {
+        folderId: id,
+        name,
+        icon: null,
+        workspaceUuid: workspaceUuid ?? gZenWorkspaces.activeWorkspace,
+        parentFolderId: null,
+        live: null,
+        children: [],
+      },
+    },
+  };
+}
+
+function tombstone(id) {
+  return { id, deleted: true };
+}

src/zen/tests/folders/browser_folder_owner_tabs.js

@@ -3,7 +3,7 @@
 
 "use strict";
 
-add_task(async function test_Duplicate_Tab_Inside_Folder() {
+add_task(async function test_Owned_Tab_Inside_Folder() {
   await SpecialPowers.pushPrefEnv({
     set: [["zen.folders.owned-tabs-in-folder", true]],
   });
@@ -40,7 +40,7 @@ add_task(async function test_Duplicate_Tab_Inside_Folder() {
   await SpecialPowers.popPrefEnv();
 });
 
-add_task(async function test_Duplicate_Tab_Inside_Folder_Unpinned() {
+add_task(async function test_Owned_Tab_Inside_Folder_Unpinned() {
   await SpecialPowers.pushPrefEnv({
     set: [["zen.folders.owned-tabs-in-folder", false]],
   });
@@ -72,3 +72,56 @@ add_task(async function test_Duplicate_Tab_Inside_Folder_Unpinned() {
   await removeFolder(folder);
   await SpecialPowers.popPrefEnv();
 });
+
+add_task(async function test_Duplicate_Tab_Inside_Folder_Pref_Enabled() {
+  await SpecialPowers.pushPrefEnv({
+    set: [["zen.folders.owned-tabs-in-folder", true]],
+  });
+  const selectedTab = gBrowser.selectedTab;
+  const tab = BrowserTestUtils.addTab(gBrowser, "about:blank");
+  const folder = await gZenFolders.createFolder([tab], {
+    renameFolder: false,
+  });
+  gBrowser.selectedTab = tab;
+
+  const newTab = gBrowser.duplicateTab(tab);
+  await BrowserTestUtils.waitForEvent(newTab, "SSTabRestored");
+
+  Assert.equal(
+    folder.tabs.length,
+    3,
+    "Folder contains its empty tab, original tab, and duplicated tab"
+  );
+  Assert.equal(newTab.group, folder, "Duplicated tab remains in the folder");
+
+  gBrowser.selectedTab = selectedTab;
+  await removeFolder(folder);
+  await SpecialPowers.popPrefEnv();
+});
+
+add_task(async function test_Duplicate_Tab_Inside_Folder_Pref_Disabled() {
+  await SpecialPowers.pushPrefEnv({
+    set: [["zen.folders.owned-tabs-in-folder", false]],
+  });
+  const selectedTab = gBrowser.selectedTab;
+  const tab = BrowserTestUtils.addTab(gBrowser, "about:blank");
+  const folder = await gZenFolders.createFolder([tab], {
+    renameFolder: false,
+  });
+  gBrowser.selectedTab = tab;
+
+  const newTab = gBrowser.duplicateTab(tab);
+  await BrowserTestUtils.waitForEvent(newTab, "SSTabRestored");
+
+  Assert.equal(
+    folder.tabs.length,
+    2,
+    "Folder contains its empty tab and original tab"
+  );
+  ok(!newTab.group, "Duplicated tab remains outside the folder");
+
+  gBrowser.selectedTab = selectedTab;
+  BrowserTestUtils.removeTab(newTab);
+  await removeFolder(folder);
+  await SpecialPowers.popPrefEnv();
+});

src/zen/tests/moz.build

@@ -6,12 +6,14 @@ BROWSER_CHROME_MANIFESTS += [
     "boosts/browser.toml",
     "compact_mode/browser.toml",
     "container_essentials/browser.toml",
+    "device_sync/browser.toml",
     "folders/browser.toml",
     "glance/browser.toml",
     "live-folders/browser.toml",
     "media/browser.toml",
     "pinned/browser.toml",
     "popover/browser.toml",
+    "share/browser.toml",
     "site_control/browser.toml",
     "space_routing/browser.toml",
     "spaces/browser.toml",

src/zen/tests/share/browser.toml

@@ -0,0 +1,22 @@
+# 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/.
+
+[DEFAULT]
+prefs = [
+  "zen.share.base-url=https://example.com",
+  "zen.share.dont-ask-before-sharing=true",
+]
+support-files = [
+  "head.js",
+]
+
+["browser_share_client.js"]
+
+["browser_share_import.js"]
+
+["browser_share_serialize.js"]
+
+["browser_share_split_link.js"]
+
+["browser_share_url_parsing.js"]

src/zen/tests/share/browser_share_client.js

@@ -0,0 +1,160 @@
+/* Any copyright is dedicated to the Public Domain.
+   https://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+const { HttpServer } = ChromeUtils.importESModule(
+  "resource://testing-common/httpd.sys.mjs"
+);
+
+const VALID_DOC = {
+  version: "1",
+  shared: {
+    type: "space",
+    name: "Test",
+    items: [{ type: "tab", url: "https://example.com/", label: "T" }],
+  },
+};
+
+let server;
+let base;
+
+let lastRequest = null;
+let nextResponse = null;
+
+function readBody(request) {
+  return NetUtil.readInputStreamToString(
+    request.bodyInputStream,
+    request.bodyInputStream.available()
+  );
+}
+
+add_setup(async function () {
+  server = new HttpServer();
+  server.registerPathHandler("/api/shares", (request, response) => {
+    lastRequest = {
+      method: request.method,
+      query: request.queryString,
+      apiKey: request.hasHeader("x-api-key")
+        ? request.getHeader("x-api-key")
+        : null,
+      secretKey: request.hasHeader("x-secret-key")
+        ? request.getHeader("x-secret-key")
+        : null,
+      body: readBody(request),
+    };
+    if (nextResponse) {
+      response.setStatusLine(request.httpVersion, nextResponse.status, "Err");
+      response.setHeader("Content-Type", "application/json");
+      response.write(nextResponse.body);
+      nextResponse = null;
+      return;
+    }
+    response.setStatusLine(request.httpVersion, 201, "Created");
+    response.setHeader("Content-Type", "application/json");
+    response.write(
+      JSON.stringify({
+        id: SHARE_ID,
+        name: null,
+        createdAt: new Date().toISOString(),
+        expiresAt: null,
+        size: 10,
+        url: `/api/shares/${SHARE_ID}`,
+        webUrl: `/space/${SHARE_ID}`,
+      })
+    );
+  });
+  server.registerPrefixHandler("/api/shares/", (request, response) => {
+    if (request.path.endsWith("/GONE-GONE-GONE-GONE")) {
+      response.setStatusLine(request.httpVersion, 404, "Not Found");
+      response.setHeader("Content-Type", "application/json");
+      response.write(JSON.stringify({ error: "share not found" }));
+      return;
+    }
+    response.setStatusLine(request.httpVersion, 200, "OK");
+    response.setHeader("Content-Type", "application/json");
+    response.write(
+      JSON.stringify({
+        id: SHARE_ID,
+        name: "John Zen",
+        createdAt: new Date().toISOString(),
+        expiresAt: null,
+        size: 10,
+        data: request.path.endsWith("/BADD-BADD-BADD-BADD")
+          ? { shared: [] }
+          : VALID_DOC,
+      })
+    );
+  });
+  server.start(-1);
+  base = `http://localhost:${server.identity.primaryPort}`;
+  await SpecialPowers.pushPrefEnv({
+    set: [["zen.share.base-url", base]],
+  });
+  registerCleanupFunction(() => new Promise(resolve => server.stop(resolve)));
+});
+
+add_task(async function test_create_share() {
+  const created = await ZenShareClient.createShare(VALID_DOC, {
+    name: "John Zen",
+  });
+  Assert.equal(lastRequest.secretKey, null, "no secret key by default");
+  Assert.deepEqual(
+    JSON.parse(lastRequest.body),
+    VALID_DOC,
+    "the body is the bare document"
+  );
+  Assert.equal(
+    created.link,
+    `${base}/space/${SHARE_ID}`,
+    "link is the absolute public page url"
+  );
+});
+
+add_task(async function test_secret_key_replaces_api_key() {
+  await SpecialPowers.pushPrefEnv({
+    set: [["zen.share.secret-key", "shhh"]],
+  });
+  await ZenShareClient.createShare(VALID_DOC);
+  Assert.equal(lastRequest.secretKey, "shhh", "secret key is sent");
+  Assert.equal(
+    lastRequest.apiKey,
+    null,
+    "the api key is never sent next to a secret key"
+  );
+  await SpecialPowers.popPrefEnv();
+});
+
+add_task(async function test_invalid_document_never_uploads() {
+  lastRequest = null;
+  await Assert.rejects(
+    ZenShareClient.createShare({ shared: [] }),
+    e => e.code === "invalid-document",
+    "an array shared value fails the schema"
+  );
+  await Assert.rejects(
+    ZenShareClient.createShare({
+      shared: { type: "space", name: "x", items: [], extra: true },
+    }),
+    e => e.code === "invalid-document",
+    "additionalProperties are rejected locally"
+  );
+  Assert.equal(lastRequest, null, "invalid documents never hit the server");
+});
+
+add_task(async function test_fetch_share_preview() {
+  const preview = await ZenShareClient.fetchSharePreview({ id: SHARE_ID });
+  Assert.equal(preview.name, "John Zen", "the sharer name comes back");
+  Assert.deepEqual(preview.doc, VALID_DOC, "the document comes back");
+
+  await Assert.rejects(
+    ZenShareClient.fetchSharePreview({ id: "GONE-GONE-GONE-GONE" }),
+    e => e.code === "not-found",
+    "dead shares map to not-found"
+  );
+  await Assert.rejects(
+    ZenShareClient.fetchSharePreview({ id: "BADD-BADD-BADD-BADD" }),
+    e => e.code === "invalid-document",
+    "downloaded documents are validated too"
+  );
+});

src/zen/tests/share/browser_share_import.js

@@ -0,0 +1,200 @@
+/* Any copyright is dedicated to the Public Domain.
+   https://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+let initialWorkspace;
+
+const SPACE_DOC = {
+  version: "1",
+  shared: {
+    type: "space",
+    name: "Imported Space",
+    theme: {
+      type: "gradient",
+      gradientColors: [
+        { c: [217, 105, 24], type: "explicit", isPrimary: true },
+        { c: [16, 32, 48], type: "custom", isCustom: true },
+      ],
+    },
+    items: [
+      {
+        type: "folder",
+        name: "Research",
+        icon: "chrome://browser/skin/zen-icons/selectable/star.svg",
+        items: [
+          { type: "tab", url: "https://example.com/sub", label: "Sub tab" },
+        ],
+      },
+      {
+        type: "tab",
+        url: "https://example.com/pinned",
+        label: "Pinned tab",
+        isPinned: true,
+      },
+      {
+        type: "splitView",
+        tabs: [
+          {
+            type: "tab",
+            url: "https://example.com/left",
+            label: "Left",
+            isPinned: true,
+          },
+          {
+            type: "tab",
+            url: "https://example.com/right",
+            label: "Right",
+            isPinned: true,
+          },
+        ],
+      },
+      { type: "tab", url: "https://example.com/loose", label: "Loose" },
+    ],
+  },
+};
+
+add_setup(async function () {
+  initialWorkspace = gZenWorkspaces.activeWorkspace;
+  await SpecialPowers.pushPrefEnv({
+    set: [["zen.view.show-newtab-button-top", true]],
+  });
+  registerCleanupFunction(() => cleanupSpaces(initialWorkspace));
+});
+
+add_task(async function test_overlay_preview() {
+  const restore = stubSharePreview(SPACE_DOC, "John Zen");
+  const { tab, overlay } = await openShareOverlay(
+    `${SHARE_BASE}/space/${SHARE_ID}`
+  );
+
+  Assert.ok(
+    tab.linkedBrowser.hasAttribute("zen-share-overlay-showing"),
+    "the share page is visually hidden behind the overlay"
+  );
+  Assert.equal(
+    overlay.querySelector(".zen-share-overlay-badge-title").textContent,
+    "Imported Space"
+  );
+  Assert.ok(
+    tab.hasAttribute("zen-show-sublabel"),
+    "the host tab gets the shared-by sublabel"
+  );
+
+  // Navigating away tears the overlay down and clears the sublabel.
+  const loaded = BrowserTestUtils.browserLoaded(tab.linkedBrowser);
+  BrowserTestUtils.startLoadingURIString(
+    tab.linkedBrowser,
+    "https://example.com/"
+  );
+  await loaded;
+  await TestUtils.waitForCondition(
+    () => !tab.linkedBrowser._zenShareOverlay,
+    "overlay is removed on navigation"
+  );
+  Assert.ok(
+    !tab.hasAttribute("zen-show-sublabel"),
+    "the sublabel is cleared on navigation"
+  );
+
+  BrowserTestUtils.removeTab(tab);
+  restore();
+});
+
+add_task(async function test_import_space() {
+  const restore = stubSharePreview(SPACE_DOC, "John Zen");
+  let sweepPlayed = false;
+  const restoreSweep = stubMethod(
+    gZenStartup,
+    "playWindowSweepAnimation",
+    () => (sweepPlayed = true)
+  );
+
+  const { tab, overlay } = await openShareOverlay(
+    `${SHARE_BASE}/space/${SHARE_ID}`
+  );
+  await importFromOverlay(tab, overlay);
+  await TestUtils.waitForCondition(
+    () => gZenWorkspaces.activeWorkspace !== initialWorkspace,
+    "the imported space becomes active"
+  );
+
+  const workspace = gZenWorkspaces.getActiveWorkspaceFromCache();
+  Assert.equal(workspace.name, "Imported Space", "the shared name wins");
+  Assert.deepEqual(
+    workspace.theme.gradientColors[0].c,
+    [217, 105, 24],
+    "the shared theme is applied"
+  );
+  Assert.equal(
+    workspace.theme.gradientColors[1].c,
+    "rgb(16, 32, 48)",
+    "custom colors go back to css strings locally"
+  );
+  Assert.ok(sweepPlayed, "importing a space plays the startup sweep");
+
+  const element = gZenWorkspaces.workspaceElement(workspace.uuid);
+  const pinnedKinds = [...element.pinnedTabsContainer.children]
+    .map(child => {
+      if (child.matches?.("zen-folder")) {
+        return "folder:" + child.label;
+      }
+      if (child.matches?.("tab-group[split-view-group]")) {
+        return "split";
+      }
+      return gBrowser.isTab(child) ? "tab:" + child.label : null;
+    })
+    .filter(Boolean);
+  Assert.deepEqual(
+    pinnedKinds,
+    ["folder:Research", "tab:Pinned tab", "split"],
+    "pinned items import in document order despite the new-tab-top pref"
+  );
+
+  const folder = element.querySelector("zen-folder");
+  Assert.ok(folder.collapsed, "imported folders start collapsed");
+  Assert.equal(
+    folder.iconURL,
+    "chrome://browser/skin/zen-icons/selectable/star.svg",
+    "the folder icon is restored"
+  );
+
+  const split = element.pinnedTabsContainer.querySelector(
+    "tab-group[split-view-group]"
+  );
+  Assert.ok(
+    split.tabs.every(t => t.pinned),
+    "an all-pinned shared split imports pinned"
+  );
+
+  const loose = [...element.tabsContainer.children].find(
+    child => gBrowser.isTab(child) && child.label === "Loose"
+  );
+  Assert.ok(loose, "unpinned tabs land in the normal section");
+  Assert.ok(!loose.pinned, "and stay unpinned");
+
+  restoreSweep();
+  restore();
+  await cleanupSpaces(initialWorkspace);
+});
+
+add_task(async function test_dead_link_shows_error() {
+  const restore = stubMethod(ZenShareClient, "fetchSharePreview", async () => {
+    throw new ZenShareError("not-found", "share not found");
+  });
+  const tab = gBrowser.addTrustedTab(`${SHARE_BASE}/space/${SHARE_ID}`, {
+    inBackground: false,
+  });
+  gBrowser.selectedTab = tab;
+  await TestUtils.waitForCondition(() => {
+    const status = tab.linkedBrowser._zenShareOverlay?.querySelector(
+      ".zen-share-overlay-status"
+    );
+    return (
+      status?.getAttribute("data-l10n-id") ===
+      "zen-share-import-error-dead-description"
+    );
+  }, "the dead-link message shows in the overlay");
+  BrowserTestUtils.removeTab(tab);
+  restore();
+});

src/zen/tests/share/browser_share_serialize.js

@@ -0,0 +1,129 @@
+/* Any copyright is dedicated to the Public Domain.
+   https://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+let initialWorkspace;
+
+function captureShare(action) {
+  return new Promise(resolve => {
+    const restore = stubMethod(ZenShareClient, "createShare", async doc => {
+      restore();
+      resolve(doc);
+      return {
+        id: SHARE_ID,
+        expiresAt: null,
+        webUrl: `/space/${SHARE_ID}`,
+        link: `${SHARE_BASE}/space/${SHARE_ID}`,
+      };
+    });
+    action();
+  });
+}
+
+add_setup(async function () {
+  initialWorkspace = gZenWorkspaces.activeWorkspace;
+  registerCleanupFunction(() => cleanupSpaces(initialWorkspace));
+});
+
+add_task(async function test_space_serialization() {
+  await gZenWorkspaces.createAndSaveWorkspace("Serialize Me");
+  const uuid = gZenWorkspaces.activeWorkspace;
+
+  const folderTab = makeLazyTab("https://folder.example.com/", "Folder tab");
+  const folder = gZenFolders.createFolder([folderTab], { label: "Docs" });
+  gZenFolders.setFolderUserIcon(
+    folder,
+    "chrome://browser/skin/zen-icons/selectable/star.svg"
+  );
+  const pinnedTab = makeLazyTab("https://pinned.example.com/", "Pinned");
+  gBrowser.pinTab(pinnedTab);
+  const splitA = makeLazyTab("https://a.example.com/", "Split A");
+  const splitB = makeLazyTab("https://b.example.com/", "Split B");
+  gBrowser.pinTab(splitA);
+  gBrowser.pinTab(splitB);
+  gZenViewSplitter.splitTabs([splitA, splitB], "grid", -1);
+  // Normal section: a plain tab and one that must not be shared.
+  makeLazyTab("https://normal.example.com/", "Normal");
+  makeLazyTab("about:preferences", "Internal");
+
+  const workspace = gZenWorkspaces.getActiveWorkspaceFromCache();
+  workspace.theme = {
+    type: "gradient",
+    opacity: 0.7,
+    texture: 0.3,
+    gradientColors: [
+      { c: [10, 20, 30], type: "explicit", isPrimary: true, lightness: "50" },
+      { c: "#102030", isCustom: true, type: "custom" },
+      { c: "color-mix(in srgb, red, blue)", isCustom: true, type: "custom" },
+    ],
+  };
+
+  const doc = await captureShare(() => gZenShareManager.shareSpace(uuid));
+  const item = doc.shared;
+
+  Assert.equal(item.type, "space");
+  Assert.equal(item.name, "Serialize Me");
+  Assert.deepEqual(
+    item.items.map(i => i.type),
+    ["folder", "tab", "splitView", "tab"],
+    "pinned items come first, in strip order; internal urls are dropped"
+  );
+
+  const [folderItem, pinnedItem, splitItem, normalItem] = item.items;
+  Assert.equal(folderItem.name, "Docs");
+  Assert.equal(
+    folderItem.icon,
+    "chrome://browser/skin/zen-icons/selectable/star.svg",
+    "the custom folder icon is shared"
+  );
+  Assert.equal(folderItem.items.length, 1, "folder keeps its tab");
+  Assert.ok(pinnedItem.isPinned, "loose pinned tabs carry isPinned");
+  Assert.ok(
+    splitItem.tabs.every(t => t.isPinned),
+    "split members carry their real pinned state"
+  );
+  Assert.ok(!normalItem.isPinned, "normal tabs carry no pinned flag");
+
+  const theme = item.theme;
+  Assert.ok(!("opacity" in theme), "theme opacity is stripped");
+  Assert.ok(!("texture" in theme), "theme texture is stripped");
+  Assert.equal(
+    theme.gradientColors.length,
+    2,
+    "unparseable custom colors are dropped"
+  );
+  Assert.deepEqual(
+    theme.gradientColors[1].c,
+    [16, 32, 48],
+    "custom css color strings become [r, g, b]"
+  );
+
+  const validation = await ZenShareClient.validateDocument(doc);
+  Assert.ok(
+    validation.valid,
+    "the serialized document passes the schema: " +
+      JSON.stringify(validation.errors ?? [])
+  );
+
+  await cleanupSpaces(initialWorkspace);
+});
+
+add_task(async function test_share_split_view_requires_two_tabs() {
+  let created = false;
+  const restore = stubMethod(ZenShareClient, "createShare", async () => {
+    created = true;
+    return { expiresAt: null, webUrl: "/x", link: "x" };
+  });
+  const restoreToast = stubMethod(gZenUIManager, "showToast", () => {});
+  const tab = makeLazyTab("https://only.example.com/", "Only");
+  const fakeGroup = {
+    hasAttribute: name => name === "split-view-group",
+    tabs: [tab],
+  };
+  await gZenShareManager.shareSplitView(fakeGroup);
+  Assert.ok(!created, "a split with fewer than two tabs is not shared");
+  restore();
+  restoreToast();
+  BrowserTestUtils.removeTab(tab);
+});

src/zen/tests/share/browser_share_split_link.js

@@ -0,0 +1,112 @@
+/* Any copyright is dedicated to the Public Domain.
+   https://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+let initialWorkspace;
+
+function splitDoc(pinned) {
+  return {
+    shared: {
+      type: "splitView",
+      tabs: [
+        {
+          type: "tab",
+          url: "https://example.com/one",
+          label: "One",
+          ...(pinned && { isPinned: true }),
+        },
+        {
+          type: "tab",
+          url: "https://example.com/two",
+          label: "Two",
+          ...(pinned && { isPinned: true }),
+        },
+      ],
+    },
+  };
+}
+
+function waitForSplitGroups(count) {
+  return TestUtils.waitForCondition(
+    () =>
+      document.querySelectorAll("tab-group[split-view-group]").length >= count,
+    `${count} split group(s) should exist`
+  );
+}
+
+add_setup(async function () {
+  initialWorkspace = gZenWorkspaces.activeWorkspace;
+  registerCleanupFunction(() => cleanupSpaces(initialWorkspace));
+});
+
+add_task(async function test_pinned_split_link_opens_directly() {
+  const restore = stubSharePreview(splitDoc(true));
+  const shareTab = gBrowser.addTrustedTab(`${SHARE_BASE}/split/${SHARE_ID}`, {
+    inBackground: false,
+  });
+  gBrowser.selectedTab = shareTab;
+
+  await waitForSplitGroups(1);
+  await TestUtils.waitForCondition(
+    () => !gBrowser.tabs.includes(shareTab),
+    "the share tab closes once the split opens"
+  );
+
+  const group = document.querySelector("tab-group[split-view-group]");
+  Assert.ok(gZenViewSplitter.splitViewActive, "the split view is active");
+  Assert.ok(
+    group.tabs.every(t => t.pinned),
+    "an all-pinned shared split opens pinned"
+  );
+  Assert.ok(
+    group.closest(".zen-workspace-pinned-tabs-section"),
+    "and lives in the pinned section"
+  );
+
+  restore();
+  await cleanupSpaces(initialWorkspace);
+});
+
+add_task(async function test_unpinned_split_link_stays_normal() {
+  const restore = stubSharePreview(splitDoc(false));
+  const shareTab = gBrowser.addTrustedTab(`${SHARE_BASE}/split/${SHARE_ID}`, {
+    inBackground: false,
+  });
+  gBrowser.selectedTab = shareTab;
+
+  await waitForSplitGroups(1);
+  const group = document.querySelector("tab-group[split-view-group]");
+  Assert.ok(
+    group.tabs.every(t => !t.pinned),
+    "an unpinned shared split opens unpinned"
+  );
+  Assert.ok(
+    group.closest(".zen-workspace-normal-tabs-section"),
+    "and lives in the normal section"
+  );
+
+  restore();
+  await cleanupSpaces(initialWorkspace);
+});
+
+add_task(async function test_failed_split_link_restores_tab() {
+  const restore = stubMethod(ZenShareClient, "fetchSharePreview", async () => {
+    throw new ZenShareError("not-found", "share not found");
+  });
+  const restoreToast = stubMethod(gZenUIManager, "showToast", () => {});
+  const shareTab = gBrowser.addTrustedTab(`${SHARE_BASE}/split/${SHARE_ID}`, {
+    inBackground: false,
+  });
+  gBrowser.selectedTab = shareTab;
+
+  await TestUtils.waitForCondition(
+    () => gBrowser.selectedTab === shareTab && !shareTab.hidden,
+    "the share tab is shown again when the split fails to load"
+  );
+  Assert.ok(gBrowser.tabs.includes(shareTab), "the tab is not closed");
+
+  restoreToast();
+  restore();
+  BrowserTestUtils.removeTab(shareTab);
+});

src/zen/tests/share/browser_share_url_parsing.js

@@ -0,0 +1,56 @@
+/* Any copyright is dedicated to the Public Domain.
+   https://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+add_task(async function test_slugs_and_types() {
+  for (const [slug, type] of [
+    ["space", "space"],
+    ["folder", "folder"],
+    ["split-view", "split-view"],
+    // "split" is the canonical server slug for split views.
+    ["split", "split-view"],
+  ]) {
+    const share = ZenShareClient.parseShareUrl(
+      `${SHARE_BASE}/${slug}/${SHARE_ID}`
+    );
+    Assert.equal(share?.type, type, `${slug} maps to ${type}`);
+    Assert.equal(share?.id, SHARE_ID, `${slug} keeps the id`);
+  }
+});
+
+add_task(async function test_id_normalization() {
+  const share = ZenShareClient.parseShareUrl(
+    `${SHARE_BASE}/space/aaaa-bbbb-cccc-dddd`
+  );
+  Assert.equal(share?.id, SHARE_ID, "ids are matched case-insensitively");
+});
+
+add_task(async function test_query_and_fragment_tolerated() {
+  Assert.ok(
+    ZenShareClient.parseShareUrl(`${SHARE_BASE}/space/${SHARE_ID}/`),
+    "trailing slash is accepted"
+  );
+  Assert.ok(
+    ZenShareClient.parseShareUrl(`${SHARE_BASE}/space/${SHARE_ID}?utm=x`),
+    "query strings are ignored"
+  );
+  Assert.ok(
+    ZenShareClient.parseShareUrl(`${SHARE_BASE}/space/${SHARE_ID}#frag`),
+    "fragments are ignored"
+  );
+});
+
+add_task(async function test_rejections() {
+  for (const spec of [
+    `https://not-the-server.com/space/${SHARE_ID}`,
+    `${SHARE_BASE}/space/aRO9GBjhTOTZ`, // the old 12-char id format
+    `${SHARE_BASE}/space/AAAA-BBBB-CCCC`, // too few groups
+    `${SHARE_BASE}/nonsense/${SHARE_ID}`,
+    `${SHARE_BASE}/space/${SHARE_ID}/extra`,
+    `${SHARE_BASE}/space/`,
+    "not a url",
+  ]) {
+    Assert.equal(ZenShareClient.parseShareUrl(spec), null, `rejects ${spec}`);
+  }
+});

src/zen/tests/share/head.js

@@ -0,0 +1,88 @@
+/* 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/. */
+
+"use strict";
+
+const { ZenShareClient, ZenShareError } = ChromeUtils.importESModule(
+  "resource:///modules/zen/share/ZenShareClient.sys.mjs"
+);
+
+const SHARE_BASE = "https://example.com";
+const SHARE_ID = "AAAA-BBBB-CCCC-DDDD";
+
+/**
+ * Replaces a method on an object until the current test file ends.
+ *
+ * @returns {Function} Restores the original immediately.
+ */
+function stubMethod(object, name, replacement) {
+  const original = object[name];
+  object[name] = replacement;
+  const restore = () => (object[name] = original);
+  registerCleanupFunction(restore);
+  return restore;
+}
+
+function stubSharePreview(doc, name = null) {
+  return stubMethod(ZenShareClient, "fetchSharePreview", async () => ({
+    doc,
+    name,
+  }));
+}
+
+function makeLazyTab(url, label) {
+  return gBrowser.addTrustedTab(url, {
+    createLazyBrowser: true,
+    inBackground: true,
+    skipAnimation: true,
+    lazyTabTitle: label,
+    skipRoute: true,
+  });
+}
+
+/** Opens a share link and waits for its overlay to finish loading. */
+async function openShareOverlay(spec) {
+  const tab = gBrowser.addTrustedTab(spec, { inBackground: false });
+  gBrowser.selectedTab = tab;
+  await TestUtils.waitForCondition(() => {
+    const overlay = tab.linkedBrowser._zenShareOverlay;
+    return overlay && !overlay.querySelector(".zen-share-overlay-status");
+  }, "share overlay should finish loading");
+  return { tab, overlay: tab.linkedBrowser._zenShareOverlay };
+}
+
+/** Clicks the overlay's import button and waits for the tab to close. */
+async function importFromOverlay(tab, overlay) {
+  const closed = BrowserTestUtils.waitForTabClosing(tab);
+  overlay.querySelector(".zen-share-overlay-add").click();
+  await closed;
+}
+
+/** Removes every workspace except the one passed, and all leftover tabs,
+ * folders and splits of the surviving workspace. */
+async function cleanupSpaces(keepUuid) {
+  for (const workspace of gZenWorkspaces.getWorkspaces()) {
+    if (workspace.uuid !== keepUuid) {
+      await gZenWorkspaces.removeWorkspace(workspace.uuid);
+    }
+  }
+  const element = gZenWorkspaces.workspaceElement(keepUuid);
+  for (const folder of [...element.querySelectorAll("zen-folder")]) {
+    await folder.delete();
+  }
+  // A fresh keeper tab lets every test tab go, including the last pinned
+  // split member that would otherwise survive and leak into the next task.
+  const keeper = BrowserTestUtils.addTab(gBrowser, "about:blank", {
+    skipAnimation: true,
+  });
+  for (const tab of [...gBrowser.tabs]) {
+    if (tab !== keeper && !tab.hasAttribute("zen-empty-tab")) {
+      BrowserTestUtils.removeTab(tab);
+    }
+  }
+  await TestUtils.waitForCondition(
+    () => !document.querySelector("tab-group[split-view-group]"),
+    "no split groups should survive cleanup"
+  );
+}

src/zen/tests/welcome/browser_welcome.js

@@ -95,6 +95,12 @@ add_task(async function test_Welcome_Steps() {
   await goNextWelcomePage("zen-generic-next");
   ok(true, "Welcome Search Step Test Finished");
 
+  await TestUtils.waitForCondition(
+    () => currentPageContent()?.getAttribute("page") === "essentials",
+    "the ad blocking page to be skipped when uBlock is unavailable"
+  );
+  ok(true, "Welcome Block Ads Step Test Finished");
+
   const essentials = currentPageContent().querySelectorAll(
     "#zen-welcome-essentials .zen-welcome-essential"
   );

src/zen/vendor/motion.dep

@@ -1,2 +1,2 @@
 // Ignore license in this file
-https://cdn.jsdelivr.net/npm/motion@latest/dist/motion.js: v12.23.11
+https://cdn.jsdelivr.net/npm/motion@latest/dist/motion.js: v13.2.0

src/zen/welcome/ZenWelcome.mjs

@@ -6,6 +6,10 @@
   let lazy = {};
 
   ChromeUtils.defineESModuleGetters(lazy, {
+    AddonManager: "resource://gre/modules/AddonManager.sys.mjs",
+    CustomizableUI:
+      "moz-src:///browser/components/customizableui/CustomizableUI.sys.mjs",
+    AddonRepository: "resource://gre/modules/addons/AddonRepository.sys.mjs",
     SearchService: "moz-src:///toolkit/components/search/SearchService.sys.mjs",
   });
 
@@ -26,11 +30,33 @@
     { url: "https://figma.com", icon: "figma", color: "#f24e1e" },
   ];
 
+  const kAdBlockerId = "uBlock0@raymondhill.net";
+
   const gChoices = {
     setDefaultBrowser: false,
     essentials: new Set(),
+    blockAds: true,
   };
 
+  let _adBlocker;
+
+  async function fetchAdBlocker() {
+    if (_adBlocker !== undefined) {
+      return _adBlocker;
+    }
+    try {
+      const [found, installed] = await Promise.all([
+        lazy.AddonRepository.getAddonsByIDs([kAdBlockerId]),
+        lazy.AddonManager.getAddonsByIDs([kAdBlockerId]),
+      ]);
+      _adBlocker = installed[0] || !found[0]?.sourceURI ? null : found[0];
+    } catch (ex) {
+      console.error(ex);
+      _adBlocker = null;
+    }
+    return _adBlocker;
+  }
+
   function clearBrowserElements() {
     for (const element of document.getElementById("browser").children) {
       if (kZenElementsToIgnore.includes(element.id)) {
@@ -131,6 +157,44 @@
     return label;
   }
 
+  const _startedInstalls = new Set();
+
+  function unpinInstalledAddon(addon) {
+    const widgetId =
+      addon.id.toLowerCase().replace(/[^a-z0-9_-]/g, "_") + "-browser-action";
+    try {
+      if (lazy.CustomizableUI.getPlacementOfWidget(widgetId)) {
+        lazy.CustomizableUI.addWidgetToArea(
+          widgetId,
+          lazy.CustomizableUI.AREA_ADDONS
+        );
+      }
+    } catch (ex) {
+      console.error(ex);
+    }
+  }
+
+  function installAddons(addons) {
+    for (const addon of addons) {
+      if (_startedInstalls.has(addon.id)) {
+        continue;
+      }
+      _startedInstalls.add(addon.id);
+      (async () => {
+        try {
+          const install = await lazy.AddonManager.getInstallForURL(
+            addon.sourceURI.spec,
+            { name: addon.name, icons: addon.icons }
+          );
+          await install.install();
+          unpinInstalledAddon(addon);
+        } catch (ex) {
+          console.error(`Failed to install ${addon.id}`, ex);
+        }
+      })();
+    }
+  }
+
   function removeVideoBackground() {
     const video = document.getElementById("zen-welcome-video");
     if (!video) {
@@ -207,6 +271,12 @@
 
     #show(index, direction) {
       const previous = this.currentPage;
+      while (this.#pages[index]?.skip?.()) {
+        index += direction;
+      }
+      if (index < 0) {
+        return;
+      }
       this.#index = index;
       const page = this.currentPage;
       if (!page) {
@@ -269,7 +339,7 @@
       if (page.id) {
         content.setAttribute("page", page.id);
       }
-      page.render(content);
+      page.render(content, this);
       this.contentContainer.appendChild(content);
       this.#content = content;
       animate(content, { opacity: [0, 1] }, kFade);
@@ -281,8 +351,8 @@
       for (const button of this.currentPage.buttons) {
         const element = document.createElement("button");
         element.className = button.primary
-          ? "zen-welcome-button primary"
-          : "zen-welcome-button";
+          ? "zen-big-accent-button primary"
+          : "zen-big-accent-button";
         document.l10n.setAttributes(element, button.l10n);
         element.addEventListener("click", () => {
           if (button.onclick?.(this) !== false) {
@@ -324,6 +394,8 @@
       await animate(`#browser > *:not(${elementsToIgnore})`, {
         opacity: [0, 1],
       });
+      _adBlocker = undefined;
+      _startedInstalls.clear();
     }
 
     async #applyChoices() {
@@ -558,6 +630,46 @@
           }
         },
       },
+      {
+        id: "block-ads",
+        title: "zen-welcome-block-ads-title",
+        descriptions: ["zen-welcome-block-ads-description"],
+        buttons: [kNextButton],
+        // Nothing to offer once we know the add-on can't be installed.
+        skip() {
+          return _adBlocker === null;
+        },
+        async render(content, pages) {
+          content.appendChild(
+            createOption({
+              id: "zen-welcome-block-ads-yes",
+              group: "zen-welcome-block-ads",
+              l10n: "zen-welcome-block-ads-yes",
+              checked: gChoices.blockAds,
+            })
+          );
+          content.appendChild(
+            createOption({
+              id: "zen-welcome-block-ads-no",
+              group: "zen-welcome-block-ads",
+              l10n: "zen-welcome-block-ads-no",
+              checked: !gChoices.blockAds,
+            })
+          );
+          // The lookup is warmed at startup, so this usually settled long ago.
+          if ((await fetchAdBlocker()) === null && content.isConnected) {
+            pages.next();
+          }
+        },
+        commit(content) {
+          gChoices.blockAds = content.querySelector(
+            "#zen-welcome-block-ads-yes"
+          ).checked;
+          if (gChoices.blockAds && _adBlocker) {
+            installAddons([_adBlocker]);
+          }
+        },
+      },
       {
         id: "essentials",
         title: "zen-welcome-essentials-title",
@@ -768,6 +880,7 @@
   }
 
   function startZenWelcome() {
+    fetchAdBlocker();
     clearBrowserElements();
     centerWindowOnScreen();
     initializeZenWelcome();

src/zen/welcome/zen-welcome.css

@@ -40,14 +40,7 @@
 }
 
 #zen-welcome {
-  --zen-welcome-accent: light-dark(
-    oklch(from var(--zen-primary-color) clamp(0.35, l, 0.6) c h),
-    oklch(from var(--zen-primary-color) clamp(0.7, l, 0.85) c h)
-  );
-  --zen-welcome-accent-button: light-dark(
-    oklch(from var(--zen-primary-color) clamp(0.35, l, 0.6) c h),
-    oklch(from var(--zen-primary-color) clamp(0.55, l, 0.7) c h)
-  );
+  --zen-welcome-accent: var(--zen-accent-button-color);
   --zen-welcome-sidebar-bg: light-dark(#ffffff, #1c1c1e);
   --zen-welcome-content-bg: light-dark(#f6f6f8f5, #2b2b30ed);
   --zen-welcome-surface-bg: light-dark(#ffffff, #1c1c1e);
@@ -62,39 +55,6 @@
   );
 }
 
-.zen-welcome-button {
-  appearance: none;
-  border: none;
-  border-radius: 12px;
-  padding: 1.2rem 1rem;
-  background: transparent;
-  color: var(--zen-welcome-accent);
-  font: inherit;
-  font-size: 1.2rem;
-  font-weight: 600;
-  cursor: pointer;
-  will-change: transform;
-  transition: scale 0.15s ease-out;
-
-  &:hover {
-    scale: 1.03;
-    filter: brightness(1.1);
-  }
-
-  &:active {
-    scale: 1;
-  }
-
-  &.primary {
-    background: var(--zen-welcome-accent-button);
-    color: white;
-
-    &:hover {
-      filter: brightness(1.1);
-    }
-  }
-}
-
 #zen-welcome-start {
   flex-direction: column;
   -moz-window-dragging: drag;

src/zen/zen.globals.mjs

@@ -40,6 +40,8 @@ export default [
 
   "gZenViewSplitter",
 
+  "gZenShareManager",
+
   "gZenSpaceRoutingManager",
 
   "Ci",