From b1be664f4d82e72bf34da8a0b4ed95e2b81f74ca Mon Sep 17 00:00:00 2001
From: Joe Goldin <joe@joegold.in>
Date: Thu, 4 Jun 2026 04:12:02 -0700
Subject: [PATCH] gh-13027: fix window sync lockup that left synced tabs blank
 in new windows (gh-14012)

---
 src/zen/sessionstore/ZenWindowSync.sys.mjs | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/src/zen/sessionstore/ZenWindowSync.sys.mjs b/src/zen/sessionstore/ZenWindowSync.sys.mjs
index 12993d74b..1c1ba7b22 100644
--- a/src/zen/sessionstore/ZenWindowSync.sys.mjs
+++ b/src/zen/sessionstore/ZenWindowSync.sys.mjs
@@ -521,10 +521,13 @@ class nsZenWindowSync {
     if (flags & SYNC_FLAG_ICON) {
       aTargetItem.zenStaticIcon = aOriginalItem.zenStaticIcon;
       if (gBrowser.isTab(aOriginalItem)) {
-        gBrowser.setIcon(
-          aTargetItem,
-          aOriginalItem.getAttribute("image") || gBrowser.getIcon(aOriginalItem)
-        );
+        try {
+          gBrowser.setIcon(
+            aTargetItem,
+            aOriginalItem.getAttribute("image") ||
+              gBrowser.getIcon(aOriginalItem)
+          );
+        } catch {}
       } else if (aOriginalItem.isZenFolder) {
         // Icons are a zen-only feature for tab groups.
         gZenFolders.setFolderUserIcon(aTargetItem, aOriginalItem.iconURL);
@@ -1542,6 +1545,7 @@ class nsZenWindowSync {
       console.error(`Error moving active tabs to other windows on close:`, e);
     }
     resolve();
+    this.#docShellSwitchPromise = null;
   }
 
   on_WindowCloseAndBrowserFlushed(aBrowsers) {