From bcdd9c0567ce02b4c2f82d2a84b974b140ba9c5c Mon Sep 17 00:00:00 2001
From: Andrey Bochkarev <50177704+octaviusz@users.noreply.github.com>
Date: Fri, 9 Jan 2026 03:38:02 +0300
Subject: [PATCH] fix: Fix indentation and `activeTabs` on new folder tab,
 p=#11846

---
 src/zen/folders/ZenFolders.mjs | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/zen/folders/ZenFolders.mjs b/src/zen/folders/ZenFolders.mjs
index 90722e5ed..49ba35bc5 100644
--- a/src/zen/folders/ZenFolders.mjs
+++ b/src/zen/folders/ZenFolders.mjs
@@ -219,7 +219,12 @@ class nsZenFolders extends nsZenDOMOperatedFeature {
     const isActiveFolder = group?.activeGroups?.length > 0;
 
     if (isActiveFolder) {
-      group.activeTabs = [...new Set([...group.activeTabs, tab])].sort((a, b) => a._tPos > b._tPos);
+      for (const folder of group.activeGroups) {
+        folder.activeTabs = [...new Set([...folder.activeTabs, tab])].sort(
+          (a, b) => a._tPos > b._tPos
+        );
+        this.setFolderIndentation([tab], folder, /* for collapse = */ true);
+      }
     }
 
     if (group.hasAttribute('split-view-group') && group.hasAttribute('zen-pinned-changed')) {