From 5fb931daad8a7cd3304e5a7ad3c95cf4a84adfcb Mon Sep 17 00:00:00 2001
From: "mr. m" <91018726+mr-cheffy@users.noreply.github.com>
Date: Fri, 20 Mar 2026 16:56:06 +0100
Subject: [PATCH] gh-12841: Fixed creating an unexpected folder in a second
 window when a new space is created (gh-12857)

---
 build/windows/sign.ps1                     | 4 ++--
 configs/windows/mozconfig                  | 4 ++--
 src/zen/sessionstore/ZenWindowSync.sys.mjs | 6 ++++++
 3 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/build/windows/sign.ps1 b/build/windows/sign.ps1
index a5966550c..37d049316 100644
--- a/build/windows/sign.ps1
+++ b/build/windows/sign.ps1
@@ -142,9 +142,9 @@ function SignAndPackage($name) {
     $env:ZEN_SETUP_EXE_PATH="$PWD\windsign-temp\windows-x64-obj-$name\browser\installer\windows\instgen\setup.exe"
 
     if ($name -eq "arm64") {
-        $env:WIN32_REDIST_DIR="$PWD\win-cross\vs2026\VC\Redist\MSVC\14.38.33135\arm64\Microsoft.VC143.CRT"
+        $env:WIN32_REDIST_DIR="$PWD\win-cross\vs2026\VC\Redist\MSVC\14.50.35719\arm64\Microsoft.VC143.CRT"
     } else {
-        $env:WIN32_REDIST_DIR="$PWD\win-cross\vs2026\VC\Redist\MSVC\14.38.33135\x64\Microsoft.VC143.CRT"
+        $env:WIN32_REDIST_DIR="$PWD\win-cross\vs2026\VC\Redist\MSVC\14.50.35719\x64\Microsoft.VC143.CRT"
     }
 
     $env:MAR="..\\build\\windows\\mar.exe"
diff --git a/configs/windows/mozconfig b/configs/windows/mozconfig
index fd1e5bfb7..a341e5196 100644
--- a/configs/windows/mozconfig
+++ b/configs/windows/mozconfig
@@ -16,9 +16,9 @@ if test "$ZEN_CROSS_COMPILING"; then
   CROSS_COMPILE=1
 
   if test "$SURFER_COMPAT" = "aarch64"; then
-    export WIN32_REDIST_DIR="$(echo ~)/win-cross/vs2026/VC/Redist/MSVC/14.38.33135/arm64/Microsoft.VC143.CRT"
+    export WIN32_REDIST_DIR="$(echo ~)/win-cross/vs2026/VC/Redist/MSVC/14.50.35719/arm64/Microsoft.VC143.CRT"
   else
-    export WIN32_REDIST_DIR="$(echo ~)/win-cross/vs2026/VC/Redist/MSVC/14.38.33135/x64/Microsoft.VC143.CRT"
+    export WIN32_REDIST_DIR="$(echo ~)/win-cross/vs2026/VC/Redist/MSVC/14.50.35719/x64/Microsoft.VC143.CRT"
   fi
 fi
 
diff --git a/src/zen/sessionstore/ZenWindowSync.sys.mjs b/src/zen/sessionstore/ZenWindowSync.sys.mjs
index 166fe9d19..4118ff0ac 100644
--- a/src/zen/sessionstore/ZenWindowSync.sys.mjs
+++ b/src/zen/sessionstore/ZenWindowSync.sys.mjs
@@ -1495,6 +1495,12 @@ class nsZenWindowSync {
 
   on_TabGroupCreate(aEvent) {
     const tabGroup = aEvent.target;
+    // See gh-12841, when creating a new space, the tab group create
+    // event is fired for the zen-workspace-collapsible-pins element, but
+    // its not something we want to sync across windows, so we can just ignore it.
+    if (tabGroup.tagName === "zen-workspace-collapsible-pins") {
+      return;
+    }
     if (tabGroup.id && tabGroup.alreadySynced) {
       // This tab group was opened as part of a sync operation.
       return;