From a4386de00d656a59425152b33b416b1012135d75 Mon Sep 17 00:00:00 2001
From: "mr. m" <mr.m@tuta.com>
Date: Sat, 31 Jan 2026 18:29:37 +0100
Subject: [PATCH] fix: Fixed dragging tabs to different windows causing freeze,
 b=closes #12178, c=tabs

---
 .../sessionstore/ZenSessionManager.sys.mjs    | 15 ++++++++++++++
 src/zen/tabs/ZenPinnedTabManager.mjs          | 20 ++++++++++++++++++-
 surfer.json                                   |  2 +-
 3 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/src/zen/sessionstore/ZenSessionManager.sys.mjs b/src/zen/sessionstore/ZenSessionManager.sys.mjs
index 323b5872a..e965fd984 100644
--- a/src/zen/sessionstore/ZenSessionManager.sys.mjs
+++ b/src/zen/sessionstore/ZenSessionManager.sys.mjs
@@ -164,6 +164,21 @@ export class nsZenSessionManager {
       } catch {
         /* ignore errors reading recovery data */
       }
+      if (!data.recoverYData) {
+        try {
+          data.recoveryData = await IOUtils.readJSON(
+            PathUtils.join(
+              Services.dirsvc.get("ProfD", Ci.nsIFile).path,
+              "sessionstore-backups",
+              "recovery.jsonlz4"
+            ),
+            { decompress: true }
+          );
+          this.log("Recovered recovery data from sessionstore-backups");
+        } catch {
+          /* ignore errors reading recovery data */
+        }
+      }
       this._migrationData = data;
     } catch {
       /* ignore errors during migration */
diff --git a/src/zen/tabs/ZenPinnedTabManager.mjs b/src/zen/tabs/ZenPinnedTabManager.mjs
index ed812990f..33f76a1a9 100644
--- a/src/zen/tabs/ZenPinnedTabManager.mjs
+++ b/src/zen/tabs/ZenPinnedTabManager.mjs
@@ -563,7 +563,25 @@ class nsZenPinnedTabManager extends nsZenDOMOperatedFeature {
       return false;
     }
     movingTabs = movingTabs.map((tab) => {
-      return tab.ownerGlobal !== window ? gBrowser.adoptTab(tab) : tab;
+      let workspaceId;
+      if (tab.ownerGlobal !== window) {
+        if (
+          !tab.hasAttribute("zen-essential") &&
+          tab.getAttribute("zen-workspace-id") != gZenWorkspaces.activeWorkspace
+        ) {
+          workspaceId = gZenWorkspaces.activeWorkspace;
+          tab.ownerGlobal.gBrowser.selectedTab = tab.ownerGlobal.gBrowser._findTabToBlurTo(
+            tab,
+            movingTabs
+          );
+          tab.ownerGlobal.gZenWorkspaces.moveTabToWorkspace(tab, workspaceId);
+        }
+        tab = gBrowser.adoptTab(tab);
+        if (workspaceId) {
+          tab.setAttribute("zen-workspace-id", workspaceId);
+        }
+      }
+      return tab;
     });
     try {
       const pinnedTabsTarget = event.target.closest(
diff --git a/surfer.json b/surfer.json
index 5f1d833d3..9a8442f96 100644
--- a/surfer.json
+++ b/surfer.json
@@ -20,7 +20,7 @@
       "brandShortName": "Zen",
       "brandFullName": "Zen Browser",
       "release": {
-        "displayVersion": "1.18.3b",
+        "displayVersion": "1.18.4b",
         "github": {
           "repo": "zen-browser/desktop"
         },