From cd0713a7ee728fbbfbdecdddf3f67bc7495e4ff1 Mon Sep 17 00:00:00 2001
From: "mr. m" <91018726+mr-cheffy@users.noreply.github.com>
Date: Sat, 21 Mar 2026 13:55:34 +0100
Subject: [PATCH] no-bug: Only animate tabs from other folders when adding them
 (gh-12868)

---
 src/zen/folders/ZenFolder.mjs | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/src/zen/folders/ZenFolder.mjs b/src/zen/folders/ZenFolder.mjs
index abd7e162e..0d33826c6 100644
--- a/src/zen/folders/ZenFolder.mjs
+++ b/src/zen/folders/ZenFolder.mjs
@@ -287,14 +287,20 @@ export class nsZenFolder extends MozTabbrowserTabGroup {
   }
 
   addTabs(tabs) {
+    let tabsFromOutside = [];
+    for (let tab of tabs) {
+      if (tab.group !== this) {
+        tabsFromOutside.push(tab);
+      }
+    }
     super.addTabs(tabs);
     if (
       this.collapsed &&
       !gZenFolders._sessionRestoring &&
       this.isLiveFolder &&
-      tabs.length
+      tabsFromOutside.length
     ) {
-      tabs.forEach(tab => {
+      tabsFromOutside.forEach(tab => {
         tab.setAttribute("folder-active", "true");
       });
       gZenFolders.animateCollapse(this);