From e34ed3e882af30a6fe96b802459ed9191fda9f5e Mon Sep 17 00:00:00 2001
From: "mr. m" <mr.m@tuta.com>
Date: Thu, 29 Jan 2026 07:39:09 +0100
Subject: [PATCH] feat: Fixed unpinning an essential tab directly from
 shortcuts, b=no-bug, c=folders, split-view, tabs, workspaces

---
 .../tabbrowser/content/tabbrowser-js.patch    | 157 +++++++++---------
 src/zen/folders/ZenFolders.mjs                |  72 ++++----
 src/zen/split-view/ZenViewSplitter.mjs        |  78 ++++-----
 src/zen/tabs/ZenPinnedTabManager.mjs          |   5 +-
 src/zen/workspaces/ZenWorkspaces.mjs          |   2 +-
 5 files changed, 163 insertions(+), 151 deletions(-)

diff --git a/src/browser/components/tabbrowser/content/tabbrowser-js.patch b/src/browser/components/tabbrowser/content/tabbrowser-js.patch
index 60652385a..6ac951dc8 100644
--- a/src/browser/components/tabbrowser/content/tabbrowser-js.patch
+++ b/src/browser/components/tabbrowser/content/tabbrowser-js.patch
@@ -1,5 +1,5 @@
 diff --git a/browser/components/tabbrowser/content/tabbrowser.js b/browser/components/tabbrowser/content/tabbrowser.js
-index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835d40793f4 100644
+index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..7f759f43a4aa1e0d96f8003a50c5df269ec4a131 100644
 --- a/browser/components/tabbrowser/content/tabbrowser.js
 +++ b/browser/components/tabbrowser/content/tabbrowser.js
 @@ -398,6 +398,7 @@
@@ -119,7 +119,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
  
        aTab.setAttribute("pinned", "true");
        this._updateTabBarForPinnedTabs();
-@@ -931,11 +994,18 @@
+@@ -931,11 +994,19 @@
        }
  
        this.#handleTabMove(aTab, () => {
@@ -133,13 +133,14 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
          // and back into arrowscrollbox.
          aTab.removeAttribute("pinned");
 -        this.tabContainer.arrowScrollbox.prepend(aTab);
++        aTab.removeAttribute("zen-essential");
 +        if (!handled) {
 +          gZenWorkspaces.activeWorkspaceStrip.prepend(aTab);
 +        }
        });
  
        aTab.style.marginInlineStart = "";
-@@ -1112,6 +1182,9 @@
+@@ -1112,6 +1183,9 @@
  
        let LOCAL_PROTOCOLS = ["chrome:", "about:", "resource:", "data:"];
  
@@ -149,7 +150,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
        if (
          aIconURL &&
          !LOCAL_PROTOCOLS.some(protocol => aIconURL.startsWith(protocol))
-@@ -1121,6 +1194,9 @@
+@@ -1121,6 +1195,9 @@
          );
          return;
        }
@@ -159,7 +160,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
  
        let browser = this.getBrowserForTab(aTab);
        browser.mIconURL = aIconURL;
-@@ -1393,7 +1469,6 @@
+@@ -1393,7 +1470,6 @@
  
        // Preview mode should not reset the owner
        if (!this._previewMode && !oldTab.selected) {
@@ -167,7 +168,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
        }
  
        let lastRelatedTab = this._lastRelatedTabMap.get(oldTab);
-@@ -1484,6 +1559,7 @@
+@@ -1484,6 +1560,7 @@
        if (!this._previewMode) {
          newTab.recordTimeFromUnloadToReload();
          newTab.updateLastAccessed();
@@ -175,7 +176,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
          oldTab.updateLastAccessed();
          // if this is the foreground window, update the last-seen timestamps.
          if (this.ownerGlobal == BrowserWindowTracker.getTopWindow()) {
-@@ -1636,6 +1712,9 @@
+@@ -1636,6 +1713,9 @@
        }
  
        let activeEl = document.activeElement;
@@ -185,7 +186,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
        // If focus is on the old tab, move it to the new tab.
        if (activeEl == oldTab) {
          newTab.focus();
-@@ -1959,6 +2038,11 @@
+@@ -1959,6 +2039,11 @@
      }
  
      _setTabLabel(aTab, aLabel, { beforeTabOpen, isContentTitle, isURL } = {}) {
@@ -197,7 +198,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
        if (!aLabel || aLabel.includes("about:reader?")) {
          return false;
        }
-@@ -2067,7 +2151,7 @@
+@@ -2067,7 +2152,7 @@
          newIndex = this.selectedTab._tPos + 1;
        }
  
@@ -206,7 +207,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
          if (this.isTabGroupLabel(targetTab)) {
            throw new Error(
              "Replacing a tab group label with a tab is not supported"
-@@ -2342,6 +2426,7 @@
+@@ -2342,6 +2427,7 @@
        uriIsAboutBlank,
        userContextId,
        skipLoad,
@@ -214,7 +215,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
      } = {}) {
        let b = document.createXULElement("browser");
        // Use the JSM global to create the permanentKey, so that if the
-@@ -2415,8 +2500,7 @@
+@@ -2415,8 +2501,7 @@
          // we use a different attribute name for this?
          b.setAttribute("name", name);
        }
@@ -224,7 +225,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
          b.setAttribute("transparent", "true");
        }
  
-@@ -2581,7 +2665,7 @@
+@@ -2581,7 +2666,7 @@
  
        let panel = this.getPanel(browser);
        let uniqueId = this._generateUniquePanelID();
@@ -233,7 +234,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
        aTab.linkedPanel = uniqueId;
  
        // Inject the <browser> into the DOM if necessary.
-@@ -2640,8 +2724,8 @@
+@@ -2640,8 +2725,8 @@
        // If we transitioned from one browser to two browsers, we need to set
        // hasSiblings=false on both the existing browser and the new browser.
        if (this.tabs.length == 2) {
@@ -244,7 +245,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
        } else {
          aTab.linkedBrowser.browsingContext.hasSiblings = this.tabs.length > 1;
        }
-@@ -2828,7 +2912,6 @@
+@@ -2828,7 +2913,6 @@
              this.selectedTab = this.addTrustedTab(BROWSER_NEW_TAB_URL, {
                tabIndex: tab._tPos + 1,
                userContextId: tab.userContextId,
@@ -252,7 +253,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
                focusUrlBar: true,
              });
              resolve(this.selectedBrowser);
-@@ -2938,6 +3021,9 @@
+@@ -2938,6 +3022,9 @@
          schemelessInput,
          hasValidUserGestureActivation = false,
          textDirectiveUserActivation = false,
@@ -262,7 +263,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
        } = {}
      ) {
        // all callers of addTab that pass a params object need to pass
-@@ -2948,10 +3034,17 @@
+@@ -2948,10 +3035,17 @@
          );
        }
  
@@ -280,7 +281,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
        // If we're opening a foreground tab, set the owner by default.
        ownerTab ??= inBackground ? null : this.selectedTab;
  
-@@ -2959,6 +3052,7 @@
+@@ -2959,6 +3053,7 @@
        if (this.selectedTab.owner) {
          this.selectedTab.owner = null;
        }
@@ -288,7 +289,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
  
        // Find the tab that opened this one, if any. This is used for
        // determining positioning, and inherited attributes such as the
-@@ -3011,6 +3105,22 @@
+@@ -3011,6 +3106,22 @@
            noInitialLabel,
            skipBackgroundNotify,
          });
@@ -311,7 +312,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
          if (insertTab) {
            // Insert the tab into the tab container in the correct position.
            this.#insertTabAtIndex(t, {
-@@ -3019,6 +3129,7 @@
+@@ -3019,6 +3130,7 @@
              ownerTab,
              openerTab,
              pinned,
@@ -319,7 +320,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
              bulkOrderedOpen,
              tabGroup: tabGroup ?? openerTab?.group,
            });
-@@ -3037,6 +3148,7 @@
+@@ -3037,6 +3149,7 @@
            openWindowInfo,
            skipLoad,
            triggeringRemoteType,
@@ -327,7 +328,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
          }));
  
          if (focusUrlBar) {
-@@ -3161,6 +3273,12 @@
+@@ -3161,6 +3274,12 @@
          }
        }
  
@@ -340,7 +341,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
        // Additionally send pinned tab events
        if (pinned) {
          this.#notifyPinnedStatus(t);
-@@ -3375,6 +3493,7 @@
+@@ -3375,6 +3494,7 @@
          isAdoptingGroup = false,
          isUserTriggered = false,
          telemetryUserCreateSource = "unknown",
@@ -348,7 +349,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
        } = {}
      ) {
        if (
-@@ -3385,9 +3504,6 @@
+@@ -3385,9 +3505,6 @@
              !this.isSplitViewWrapper(tabOrSplitView)
          )
        ) {
@@ -358,7 +359,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
        }
  
        if (!color) {
-@@ -3408,9 +3524,14 @@
+@@ -3408,9 +3525,14 @@
          label,
          isAdoptingGroup
        );
@@ -375,7 +376,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
        );
        group.addTabs(tabsAndSplitViews);
  
-@@ -3531,7 +3652,7 @@
+@@ -3531,7 +3653,7 @@
        }
  
        this.#handleTabMove(tab, () =>
@@ -384,7 +385,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
        );
      }
  
-@@ -3599,6 +3720,7 @@
+@@ -3599,6 +3721,7 @@
          color: group.color,
          insertBefore: newTabs[0],
          isAdoptingGroup: true,
@@ -392,7 +393,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
        });
      }
  
-@@ -3746,6 +3868,7 @@
+@@ -3746,6 +3869,7 @@
          openWindowInfo,
          skipLoad,
          triggeringRemoteType,
@@ -400,7 +401,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
        }
      ) {
        // If we don't have a preferred remote type (or it is `NOT_REMOTE`), and
-@@ -3815,6 +3938,7 @@
+@@ -3815,6 +3939,7 @@
            openWindowInfo,
            name,
            skipLoad,
@@ -408,7 +409,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
          });
        }
  
-@@ -4003,7 +4127,7 @@
+@@ -4003,7 +4128,7 @@
          // Add a new tab if needed.
          if (!tab) {
            let createLazyBrowser =
@@ -417,7 +418,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
  
            let url = "about:blank";
            if (tabData.entries?.length) {
-@@ -4040,8 +4164,10 @@
+@@ -4040,8 +4165,10 @@
              insertTab: false,
              skipLoad: true,
              preferredRemoteType,
@@ -429,7 +430,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
            if (select) {
              tabToSelect = tab;
            }
-@@ -4053,7 +4179,8 @@
+@@ -4053,7 +4180,8 @@
            this.pinTab(tab);
            // Then ensure all the tab open/pinning information is sent.
            this._fireTabOpen(tab, {});
@@ -439,7 +440,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
            let { groupId } = tabData;
            const tabGroup = tabGroupWorkingData.get(groupId);
            // if a tab refers to a tab group we don't know, skip any group
-@@ -4067,7 +4194,10 @@
+@@ -4067,7 +4195,10 @@
                  tabGroup.stateData.id,
                  tabGroup.stateData.color,
                  tabGroup.stateData.collapsed,
@@ -451,7 +452,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
                );
                tabsFragment.appendChild(tabGroup.node);
              }
-@@ -4112,9 +4242,23 @@
+@@ -4112,9 +4243,23 @@
        // to remove the old selected tab.
        if (tabToSelect) {
          let leftoverTab = this.selectedTab;
@@ -475,7 +476,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
  
        if (tabs.length > 1 || !tabs[0].selected) {
          this._updateTabsAfterInsert();
-@@ -4305,11 +4449,14 @@
+@@ -4305,11 +4450,14 @@
        if (ownerTab) {
          tab.owner = ownerTab;
        }
@@ -491,7 +492,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
          if (
            !bulkOrderedOpen &&
            ((openerTab &&
-@@ -4321,7 +4468,7 @@
+@@ -4321,7 +4469,7 @@
            let lastRelatedTab =
              openerTab && this._lastRelatedTabMap.get(openerTab);
            let previousTab = lastRelatedTab || openerTab || this.selectedTab;
@@ -500,7 +501,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
              tabGroup = previousTab.group;
            }
            if (
-@@ -4337,7 +4484,7 @@
+@@ -4337,7 +4485,7 @@
                  previousTab.splitview
                ) + 1;
            } else if (previousTab.visible) {
@@ -509,7 +510,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
            } else if (previousTab == FirefoxViewHandler.tab) {
              elementIndex = 0;
            }
-@@ -4365,14 +4512,14 @@
+@@ -4365,14 +4513,14 @@
        }
        // Ensure index is within bounds.
        if (tab.pinned) {
@@ -528,7 +529,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
  
        if (pinned && !itemAfter?.pinned) {
          itemAfter = null;
-@@ -4385,7 +4532,7 @@
+@@ -4385,7 +4533,7 @@
  
        this.tabContainer._invalidateCachedTabs();
  
@@ -537,7 +538,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
          if (
            (this.isTab(itemAfter) && itemAfter.group == tabGroup) ||
            this.isSplitViewWrapper(itemAfter)
-@@ -4416,7 +4563,11 @@
+@@ -4416,7 +4564,11 @@
          const tabContainer = pinned
            ? this.tabContainer.pinnedTabsContainer
            : this.tabContainer;
@@ -549,7 +550,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
        }
  
        if (tab.group?.collapsed) {
-@@ -4431,6 +4582,7 @@
+@@ -4431,6 +4583,7 @@
        if (pinned) {
          this._updateTabBarForPinnedTabs();
        }
@@ -557,7 +558,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
  
        TabBarVisibility.update();
      }
-@@ -4983,6 +5135,7 @@
+@@ -4983,6 +5136,7 @@
          telemetrySource,
        } = {}
      ) {
@@ -565,7 +566,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
        // When 'closeWindowWithLastTab' pref is enabled, closing all tabs
        // can be considered equivalent to closing the window.
        if (
-@@ -5072,6 +5225,7 @@
+@@ -5072,6 +5226,7 @@
          if (lastToClose) {
            this.removeTab(lastToClose, aParams);
          }
@@ -573,7 +574,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
        } catch (e) {
          console.error(e);
        }
-@@ -5110,6 +5264,12 @@
+@@ -5110,6 +5265,12 @@
          aTab._closeTimeNoAnimTimerId = Glean.browserTabclose.timeNoAnim.start();
        }
  
@@ -586,7 +587,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
        // Handle requests for synchronously removing an already
        // asynchronously closing tab.
        if (!animate && aTab.closing) {
-@@ -5124,6 +5284,9 @@
+@@ -5124,6 +5285,9 @@
        // state).
        let tabWidth = window.windowUtils.getBoundsWithoutFlushing(aTab).width;
        let isLastTab = this.#isLastTabInWindow(aTab);
@@ -596,7 +597,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
        if (
          !this._beginRemoveTab(aTab, {
            closeWindowFastpath: true,
-@@ -5172,7 +5335,13 @@
+@@ -5172,7 +5336,13 @@
          // We're not animating, so we can cancel the animation stopwatch.
          Glean.browserTabclose.timeAnim.cancel(aTab._closeTimeAnimTimerId);
          aTab._closeTimeAnimTimerId = null;
@@ -611,7 +612,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
          return;
        }
  
-@@ -5306,7 +5475,7 @@
+@@ -5306,7 +5476,7 @@
            closeWindowWithLastTab != null
              ? closeWindowWithLastTab
              : !window.toolbar.visible ||
@@ -620,7 +621,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
  
          if (closeWindow) {
            // We've already called beforeunload on all the relevant tabs if we get here,
-@@ -5330,6 +5499,7 @@
+@@ -5330,6 +5500,7 @@
  
          newTab = true;
        }
@@ -628,7 +629,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
        aTab._endRemoveArgs = [closeWindow, newTab];
  
        // swapBrowsersAndCloseOther will take care of closing the window without animation.
-@@ -5370,13 +5540,7 @@
+@@ -5370,13 +5541,7 @@
        aTab._mouseleave();
  
        if (newTab) {
@@ -643,7 +644,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
        } else {
          TabBarVisibility.update();
        }
-@@ -5509,6 +5673,7 @@
+@@ -5509,6 +5674,7 @@
          this.tabs[i]._tPos = i;
        }
  
@@ -651,7 +652,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
        if (!this._windowIsClosing) {
          // update tab close buttons state
          this.tabContainer._updateCloseButtons();
-@@ -5732,6 +5897,7 @@
+@@ -5732,6 +5898,7 @@
        }
  
        let excludeTabs = new Set(aExcludeTabs);
@@ -659,7 +660,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
  
        // If this tab has a successor, it should be selectable, since
        // hiding or closing a tab removes that tab as a successor.
-@@ -5744,15 +5910,22 @@
+@@ -5744,15 +5911,22 @@
          !excludeTabs.has(aTab.owner) &&
          Services.prefs.getBoolPref("browser.tabs.selectOwnerOnClose")
        ) {
@@ -684,7 +685,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
        let tab = this.tabContainer.findNextTab(aTab, {
          direction: 1,
          filter: _tab => remainingTabs.includes(_tab),
-@@ -5766,7 +5939,7 @@
+@@ -5766,7 +5940,7 @@
        }
  
        if (tab) {
@@ -693,7 +694,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
        }
  
        // If no qualifying visible tab was found, see if there is a tab in
-@@ -5787,7 +5960,7 @@
+@@ -5787,7 +5961,7 @@
          });
        }
  
@@ -702,7 +703,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
      }
  
      _blurTab(aTab) {
-@@ -5798,7 +5971,7 @@
+@@ -5798,7 +5972,7 @@
       * @returns {boolean}
       *   False if swapping isn't permitted, true otherwise.
       */
@@ -711,7 +712,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
        // Do not allow transfering a private tab to a non-private window
        // and vice versa.
        if (
-@@ -5852,6 +6025,7 @@
+@@ -5852,6 +6026,7 @@
        // fire the beforeunload event in the process.  Close the other
        // window if this was its last tab.
        if (
@@ -719,7 +720,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
          !remoteBrowser._beginRemoveTab(aOtherTab, {
            adoptedByTab: aOurTab,
            closeWindowWithLastTab: true,
-@@ -5863,7 +6037,7 @@
+@@ -5863,7 +6038,7 @@
        // If this is the last tab of the window, hide the window
        // immediately without animation before the docshell swap, to avoid
        // about:blank being painted.
@@ -728,7 +729,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
        if (closeWindow) {
          let win = aOtherTab.ownerGlobal;
          win.windowUtils.suppressAnimation(true);
-@@ -5987,11 +6161,13 @@
+@@ -5987,11 +6162,13 @@
        }
  
        // Finish tearing down the tab that's going away.
@@ -742,7 +743,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
  
        this.setTabTitle(aOurTab);
  
-@@ -6193,10 +6369,10 @@
+@@ -6193,10 +6370,10 @@
        SessionStore.deleteCustomTabValue(aTab, "hiddenBy");
      }
  
@@ -755,7 +756,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
          aTab.selected ||
          aTab.closing ||
          // Tabs that are sharing the screen, microphone or camera cannot be hidden.
-@@ -6254,7 +6430,8 @@
+@@ -6254,7 +6431,8 @@
       *
       * @param {MozTabbrowserTab|MozTabbrowserTabGroup|MozTabbrowserTabGroup.labelElement} aTab
       */
@@ -765,7 +766,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
        if (this.tabs.length == 1) {
          return null;
        }
-@@ -6278,12 +6455,14 @@
+@@ -6278,12 +6456,14 @@
        }
  
        // tell a new window to take the "dropped" tab
@@ -781,7 +782,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
      }
  
      /**
-@@ -6388,7 +6567,7 @@
+@@ -6388,7 +6568,7 @@
       *   `true` if element is a `<tab-group>`
       */
      isTabGroup(element) {
@@ -790,7 +791,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
      }
  
      /**
-@@ -6473,8 +6652,8 @@
+@@ -6473,8 +6653,8 @@
        }
  
        // Don't allow mixing pinned and unpinned tabs.
@@ -801,7 +802,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
        } else {
          tabIndex = Math.max(tabIndex, this.pinnedTabCount);
        }
-@@ -6500,10 +6679,16 @@
+@@ -6500,10 +6680,16 @@
        this.#handleTabMove(
          element,
          () => {
@@ -820,7 +821,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
            if (neighbor && this.isTab(element) && tabIndex > element._tPos) {
              neighbor.after(element);
            } else {
-@@ -6561,23 +6746,31 @@
+@@ -6561,23 +6747,31 @@
      #moveTabNextTo(element, targetElement, moveBefore = false, metricsContext) {
        if (this.isTabGroupLabel(targetElement)) {
          targetElement = targetElement.group;
@@ -858,7 +859,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
        } else if (!element.pinned && targetElement && targetElement.pinned) {
          // If the caller asks to move an unpinned element next to a pinned
          // tab, move the unpinned element to be the first unpinned element
-@@ -6590,14 +6783,34 @@
+@@ -6590,14 +6784,34 @@
          //    move the tab group right before the first unpinned tab.
          // 4. Moving a tab group and the first unpinned tab is grouped:
          //    move the tab group right before the first unpinned tab's tab group.
@@ -894,7 +895,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
          element.pinned
            ? this.tabContainer.pinnedTabsContainer
            : this.tabContainer;
-@@ -6606,7 +6819,7 @@
+@@ -6606,7 +6820,7 @@
          element,
          () => {
            if (moveBefore) {
@@ -903,7 +904,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
            } else if (targetElement) {
              targetElement.after(element);
            } else {
-@@ -6676,10 +6889,10 @@
+@@ -6676,10 +6890,10 @@
       * @param {TabMetricsContext} [metricsContext]
       */
      moveTabToExistingGroup(aTab, aGroup, metricsContext) {
@@ -916,7 +917,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
          return;
        }
        if (aTab.group && aTab.group.id === aGroup.id) {
-@@ -6751,6 +6964,7 @@
+@@ -6751,6 +6965,7 @@
  
        let state = {
          tabIndex: tab._tPos,
@@ -924,7 +925,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
        };
        if (tab.visible) {
          state.elementIndex = tab.elementIndex;
-@@ -6777,7 +6991,7 @@
+@@ -6777,7 +6992,7 @@
        let changedTabGroup =
          previousTabState.tabGroupId != currentTabState.tabGroupId;
  
@@ -933,7 +934,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
          tab.dispatchEvent(
            new CustomEvent("TabMove", {
              bubbles: true,
-@@ -6818,6 +7032,10 @@
+@@ -6818,6 +7033,10 @@
  
        moveActionCallback();
  
@@ -944,7 +945,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
        // Clear tabs cache after moving nodes because the order of tabs may have
        // changed.
        this.tabContainer._invalidateCachedTabs();
-@@ -6869,6 +7087,18 @@
+@@ -6869,6 +7088,18 @@
       *    The new tab in the current window, null if the tab couldn't be adopted.
       */
      adoptTab(aTab, { elementIndex, tabIndex, selectTab = false } = {}) {
@@ -963,7 +964,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
        // Swap the dropped tab with a new one we create and then close
        // it in the other window (making it seem to have moved between
        // windows). We also ensure that the tab we create to swap into has
-@@ -6910,6 +7140,8 @@
+@@ -6910,6 +7141,8 @@
          params.userContextId = aTab.getAttribute("usercontextid");
        }
        let newTab = this.addWebTab("about:blank", params);
@@ -972,7 +973,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
        let newBrowser = this.getBrowserForTab(newTab);
  
        aTab.container.tabDragAndDrop.finishAnimateTabMove();
-@@ -7718,7 +7950,7 @@
+@@ -7718,7 +7951,7 @@
              // preventDefault(). It will still raise the window if appropriate.
              break;
            }
@@ -981,7 +982,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
            window.focus();
            aEvent.preventDefault();
            break;
-@@ -7735,7 +7967,6 @@
+@@ -7735,7 +7968,6 @@
          }
          case "TabGroupCollapse":
            aEvent.target.tabs.forEach(tab => {
@@ -989,7 +990,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
            });
            break;
          case "TabGroupCreateByUser":
-@@ -7895,7 +8126,9 @@
+@@ -7895,7 +8127,9 @@
  
          let filter = this._tabFilters.get(tab);
          if (filter) {
@@ -999,7 +1000,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
  
            let listener = this._tabListeners.get(tab);
            if (listener) {
-@@ -8698,6 +8931,7 @@
+@@ -8698,6 +8932,7 @@
              aWebProgress.isTopLevel
            ) {
              this.mTab.setAttribute("busy", "true");
@@ -1007,7 +1008,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
              gBrowser._tabAttrModified(this.mTab, ["busy"]);
              this.mTab._notselectedsinceload = !this.mTab.selected;
            }
-@@ -8778,6 +9012,7 @@
+@@ -8778,6 +9013,7 @@
          // known defaults. Note we use the original URL since about:newtab
          // redirects to a prerendered page.
          const shouldRemoveFavicon =
@@ -1015,7 +1016,7 @@ index 0eaca7a58e0026237b71b2ad515efe84d9e8c779..632f78baf6a27ca90a0415c182476835
            !this.mBrowser.mIconURL &&
            !ignoreBlank &&
            !(originalLocation.spec in FAVICON_DEFAULTS);
-@@ -9803,7 +10038,7 @@ var TabContextMenu = {
+@@ -9803,7 +10039,7 @@ var TabContextMenu = {
      );
      contextUnpinSelectedTabs.hidden =
        !this.contextTab.pinned || !this.multiselected;
diff --git a/src/zen/folders/ZenFolders.mjs b/src/zen/folders/ZenFolders.mjs
index 3cdd78027..31f06293c 100644
--- a/src/zen/folders/ZenFolders.mjs
+++ b/src/zen/folders/ZenFolders.mjs
@@ -1038,43 +1038,47 @@ class nsZenFolders extends nsZenDOMOperatedFeature {
     const tabFolderWorkingData = new Map();
 
     for (const folderData of data) {
-      const workingData = {
-        stateData: folderData,
-        node: null,
-        containingTabsFragment: document.createDocumentFragment(),
-      };
-      tabFolderWorkingData.set(folderData.id, workingData);
+      try {
+        const workingData = {
+          stateData: folderData,
+          node: null,
+          containingTabsFragment: document.createDocumentFragment(),
+        };
+        tabFolderWorkingData.set(folderData.id, workingData);
 
-      const oldGroup = document.getElementById(folderData.id);
-      folderData.emptyTabIds.forEach((id) => {
-        oldGroup?.querySelector(`tab[id="${id}"]`)?.setAttribute("zen-empty-tab", true);
-      });
-      if (gBrowser.isTabGroup(oldGroup)) {
-        if (!folderData.splitViewGroup) {
-          const folder = this._createFolderNode({
-            id: folderData.id,
-            label: folderData.name,
-            collapsed: folderData.collapsed,
-            pinned: folderData.pinned,
-            saveOnWindowClose: folderData.saveOnWindowClose,
-            workspaceId: folderData.workspaceId,
-          });
-          folder.setAttribute("id", folderData.id);
-          workingData.node = folder;
-          oldGroup.before(folder);
-        } else {
-          workingData.node = oldGroup;
-        }
-        while (oldGroup.tabs.length) {
-          const tab = oldGroup.tabs[0];
-          if (folderData.workspaceId) {
-            tab.setAttribute("zen-workspace-id", folderData.workspaceId);
+        const oldGroup = document.getElementById(folderData.id);
+        folderData.emptyTabIds.forEach((id) => {
+          oldGroup?.querySelector(`tab[id="${id}"]`)?.setAttribute("zen-empty-tab", true);
+        });
+        if (gBrowser.isTabGroup(oldGroup)) {
+          if (!folderData.splitViewGroup) {
+            const folder = this._createFolderNode({
+              id: folderData.id,
+              label: folderData.name,
+              collapsed: folderData.collapsed,
+              pinned: folderData.pinned,
+              saveOnWindowClose: folderData.saveOnWindowClose,
+              workspaceId: folderData.workspaceId,
+            });
+            folder.setAttribute("id", folderData.id);
+            workingData.node = folder;
+            oldGroup.before(folder);
+          } else {
+            workingData.node = oldGroup;
+          }
+          while (oldGroup.tabs.length) {
+            const tab = oldGroup.tabs[0];
+            if (folderData.workspaceId) {
+              tab.setAttribute("zen-workspace-id", folderData.workspaceId);
+            }
+            workingData.containingTabsFragment.appendChild(tab);
+          }
+          if (!folderData.splitViewGroup) {
+            oldGroup.remove();
           }
-          workingData.containingTabsFragment.appendChild(tab);
-        }
-        if (!folderData.splitViewGroup) {
-          oldGroup.remove();
         }
+      } catch (e) {
+        console.error("Error restoring Zen Folders session data:", e);
       }
     }
 
diff --git a/src/zen/split-view/ZenViewSplitter.mjs b/src/zen/split-view/ZenViewSplitter.mjs
index 203646ed2..d7d4dd3bd 100644
--- a/src/zen/split-view/ZenViewSplitter.mjs
+++ b/src/zen/split-view/ZenViewSplitter.mjs
@@ -2093,48 +2093,52 @@ class nsZenViewSplitter extends nsZenDOMOperatedFeature {
     this._sessionRestoring = true;
 
     for (const groupData of data) {
-      const group = document.getElementById(groupData.groupId);
-      if (!gBrowser.isTabGroup(group)) {
-        continue;
-      }
-
-      // Backwards compatibility
-      group.setAttribute("split-view-group", "true");
-      if (!groupData?.layoutTree) {
-        this.splitTabs(group.tabs, group.gridType);
-        delete this._sessionRestoring;
-        return;
-      }
-
-      const deserializeNode = (nodeData) => {
-        if (nodeData.type === "leaf") {
-          const tab = document.getElementById(nodeData.tabId);
-          if (!tab) {
-            return null;
-          }
-          return new nsSplitLeafNode(tab, nodeData.sizeInParent);
+      try {
+        const group = document.getElementById(groupData.groupId);
+        if (!gBrowser.isTabGroup(group)) {
+          continue;
         }
 
-        const splitter = new nsSplitNode(nodeData.direction, nodeData.sizeInParent);
-        splitter._children = [];
-
-        for (const childData of nodeData.children) {
-          const childNode = deserializeNode(childData);
-          if (childNode) {
-            childNode.parent = splitter;
-            splitter._children.push(childNode);
-          }
+        // Backwards compatibility
+        group.setAttribute("split-view-group", "true");
+        if (!groupData?.layoutTree) {
+          this.splitTabs(group.tabs, group.gridType);
+          delete this._sessionRestoring;
+          return;
         }
 
-        return splitter;
-      };
+        const deserializeNode = (nodeData) => {
+          if (nodeData.type === "leaf") {
+            const tab = document.getElementById(nodeData.tabId);
+            if (!tab) {
+              return null;
+            }
+            return new nsSplitLeafNode(tab, nodeData.sizeInParent);
+          }
 
-      const layout = deserializeNode(groupData.layoutTree);
-      const splitData = this.splitTabs(group.tabs, groupData.gridType, -1);
-      if (splitData) {
-        splitData.layoutTree = layout;
-      } else {
-        gBrowser.removeTabGroup(group);
+          const splitter = new nsSplitNode(nodeData.direction, nodeData.sizeInParent);
+          splitter._children = [];
+
+          for (const childData of nodeData.children) {
+            const childNode = deserializeNode(childData);
+            if (childNode) {
+              childNode.parent = splitter;
+              splitter._children.push(childNode);
+            }
+          }
+
+          return splitter;
+        };
+
+        const layout = deserializeNode(groupData.layoutTree);
+        const splitData = this.splitTabs(group.tabs, groupData.gridType, -1);
+        if (splitData) {
+          splitData.layoutTree = layout;
+        } else {
+          gBrowser.removeTabGroup(group);
+        }
+      } catch (e) {
+        console.error("Error restoring split view session data:", e);
       }
     }
 
diff --git a/src/zen/tabs/ZenPinnedTabManager.mjs b/src/zen/tabs/ZenPinnedTabManager.mjs
index 6f5fc1b6f..ed812990f 100644
--- a/src/zen/tabs/ZenPinnedTabManager.mjs
+++ b/src/zen/tabs/ZenPinnedTabManager.mjs
@@ -603,7 +603,10 @@ class nsZenPinnedTabManager extends nsZenDOMOperatedFeature {
         let isRegularTabs = false;
         // Check for essentials container
         if (essentialTabsTarget) {
-          if (!draggedTab.hasAttribute("zen-essential") && !draggedTab?.group) {
+          if (
+            !draggedTab.hasAttribute("zen-essential") &&
+            !draggedTab?.group?.hasAttribute("split-view-group")
+          ) {
             moved = true;
             isVertical = false;
             hasActuallyMoved = this.addToEssentials(draggedTab);
diff --git a/src/zen/workspaces/ZenWorkspaces.mjs b/src/zen/workspaces/ZenWorkspaces.mjs
index b679f7328..ab27d0c9e 100644
--- a/src/zen/workspaces/ZenWorkspaces.mjs
+++ b/src/zen/workspaces/ZenWorkspaces.mjs
@@ -807,7 +807,7 @@ class nsZenWorkspaces {
         chromeFlags & Ci.nsIWebBrowserChrome.CHROME_MENUBAR;
       return this._shouldHaveWorkspaces;
     }
-    return this._shouldHaveWorkspaces;
+    return this._shouldHaveWorkspaces && !document.documentElement.hasAttribute("taskbartab");
   }
 
   get isPrivateWindow() {