From dd26ec1171f5f038a60cad7a06a8471643cd4075 Mon Sep 17 00:00:00 2001
From: "mr. m" <mr.m@tuta.com>
Date: Wed, 18 Feb 2026 12:52:26 +0100
Subject: [PATCH] fix: Fixed tabs becoming empty tabs when switching between
 windows, b=bug #12421, c=no-component

---
 .../sessionstore/ZenSessionManager.sys.mjs    |  6 +-----
 src/zen/sessionstore/ZenWindowSync.sys.mjs    | 20 ++++++++++---------
 2 files changed, 12 insertions(+), 14 deletions(-)

diff --git a/src/zen/sessionstore/ZenSessionManager.sys.mjs b/src/zen/sessionstore/ZenSessionManager.sys.mjs
index 0bcaedc4f..70b456703 100644
--- a/src/zen/sessionstore/ZenSessionManager.sys.mjs
+++ b/src/zen/sessionstore/ZenSessionManager.sys.mjs
@@ -30,10 +30,6 @@ XPCOMUtils.defineLazyPreferenceGetter(
   3
 );
 
-const SHOULD_LOG_TAB_ENTRIES = Services.prefs.getBoolPref(
-  "zen.session-store.log-tab-entries",
-  false
-);
 const SHOULD_BACKUP_FILE = Services.prefs.getBoolPref("zen.session-store.backup-file", true);
 const FILE_NAME = "zen-sessions.jsonlz4";
 
@@ -236,7 +232,7 @@ export class nsZenSessionManager {
       this._shouldRunMigration = true;
       await this.#getDataFromDBForMigration();
     }
-    if (SHOULD_LOG_TAB_ENTRIES) {
+    if (Services.prefs.getBoolPref("zen.session-store.log-tab-entries", false)) {
       for (const tab of this.#sidebar.tabs || []) {
         this.log("Tab entry in session file:", tab);
       }
diff --git a/src/zen/sessionstore/ZenWindowSync.sys.mjs b/src/zen/sessionstore/ZenWindowSync.sys.mjs
index 4c2acef32..f825ef4e8 100644
--- a/src/zen/sessionstore/ZenWindowSync.sys.mjs
+++ b/src/zen/sessionstore/ZenWindowSync.sys.mjs
@@ -715,7 +715,7 @@ class nsZenWindowSync {
         return;
       }
       lazy.TabStateCache.update(aOurTab.linkedBrowser.permanentKey, {
-        history: tabStateEntries,
+        history: Cu.cloneInto(tabStateEntries, {}),
       });
     };
     // Running `swapBrowsersAndCloseOther` doesn't expect us to use the tab after
@@ -815,17 +815,19 @@ class nsZenWindowSync {
         });
 
         let promise = this.#createPseudoImageForBrowser(otherBrowser, mySrc);
-
         await Promise.all([promiseToWait, promise]);
         callback();
-        otherBrowser.setAttribute("zen-pseudo-hidden", "true");
-        ourBrowser.removeAttribute("zen-pseudo-hidden");
-        this.#maybeRemovePseudoImageForBrowser(ourBrowser);
-      } else {
-        ourBrowser.removeAttribute("zen-pseudo-hidden");
-        this.#maybeRemovePseudoImageForBrowser(ourBrowser);
+        lazy.setTimeout(() => {
+          otherBrowser.setAttribute("zen-pseudo-hidden", "true");
+          ourBrowser.removeAttribute("zen-pseudo-hidden");
+          this.#maybeRemovePseudoImageForBrowser(ourBrowser);
+          ourBrowser.focus();
+          resolve();
+        });
+        return;
       }
-
+      ourBrowser.removeAttribute("zen-pseudo-hidden");
+      this.#maybeRemovePseudoImageForBrowser(ourBrowser);
       resolve();
     });
   }