From 7046d16956d8e9f28d49aef64eeb3a2f509deb43 Mon Sep 17 00:00:00 2001
From: "mr. m" <91018726+mr-cheffy@users.noreply.github.com>
Date: Fri, 17 Apr 2026 13:32:22 +0200
Subject: [PATCH] gh-13149: Fixed WS marking tabs as inactive in certain cases
 (gh-13298)

---
 scripts/mar_sign.sh                        | 20 ++++++++++++++++----
 src/zen/sessionstore/ZenWindowSync.sys.mjs | 10 ++++++++++
 2 files changed, 26 insertions(+), 4 deletions(-)

diff --git a/scripts/mar_sign.sh b/scripts/mar_sign.sh
index fb47c6a80..e0c02802b 100644
--- a/scripts/mar_sign.sh
+++ b/scripts/mar_sign.sh
@@ -47,10 +47,22 @@ import_cert() {
     echo "Error: public_key.der not found. Run with -g first." >&2
     exit 1
   fi
-  echo "Importing certificate into $UPDATER_CERT_DIR/release_primary.der"
-  cp "$CERT_PATH_DIR/public_key.der" "$UPDATER_CERT_DIR/release_primary.der"
-  echo "Importing certificate into $UPDATER_CERT_DIR/release_secondary.der"
-  cp "$CERT_PATH_DIR/public_key.der" "$UPDATER_CERT_DIR/release_secondary.der"
+  files=(
+    "$UPDATER_CERT_DIR/release_primary.der"
+    "$UPDATER_CERT_DIR/release_secondary.der"
+    "$UPDATER_CERT_DIR/dep1.der"
+    "$UPDATER_CERT_DIR/dep2.der"
+    "$UPDATER_CERT_DIR/xpcshellCertificate.der"
+  )
+  for file in "${files[@]}"; do
+    if [ ! -f "$file" ]; then
+      echo "Error: $file not found. Make sure the updater certificates exist." >&2
+      exit 1
+    fi
+    rm -f "$file"
+    echo "Copying $CERT_PATH_DIR/public_key.der to $file"
+    cp "$CERT_PATH_DIR/public_key.der" "$file"
+  done
   echo "Done. Rebuild the updater to embed the new certificate."
 }
 
diff --git a/src/zen/sessionstore/ZenWindowSync.sys.mjs b/src/zen/sessionstore/ZenWindowSync.sys.mjs
index 564693dca..8612601c4 100644
--- a/src/zen/sessionstore/ZenWindowSync.sys.mjs
+++ b/src/zen/sessionstore/ZenWindowSync.sys.mjs
@@ -795,6 +795,16 @@ class nsZenWindowSync {
       );
       return false;
     }
+    // Theoretical case where we are trying to swap two tabs in the same window.
+    // There has been some reports of this happening in the wild, and while it shouldn't
+    // cause any critical issues, it can cause some weird states and we should avoid it.
+    // For example, see gh-13149
+    if (aOtherTab.ownerGlobal === aOurTab.ownerGlobal) {
+      this.log(
+        `Cannot swap browsers between tabs ${aOurTab.id} and ${aOtherTab.id} because they are in the same window`
+      );
+      return false;
+    }
     // Can't swap between chrome and content processes.
     if (
       aOurTab.linkedBrowser.isRemoteBrowser !=