From 98e8af4bb991fd8edeb15c0fb8afa66bff6b5cac Mon Sep 17 00:00:00 2001
From: Ava Chow <github@achow101.com>
Date: Fri, 20 Feb 2026 14:23:51 -0800
Subject: [PATCH] wallet: Drain validation interface queue after notifications
 disconnect

When unloading a wallet, there may be unexecuted callbacks in the
validation interface queue that can still execute after we have
completed all of the other wallet shutdown tasks. Instead of letting
these run in the background, once the notifications are disconnected,
wait for the queue to drain before continuing with wallet shutdown.
---
 src/wallet/wallet.cpp | 16 +++++++++++++---
 src/wallet/wallet.h   |  3 +++
 2 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index 63dab29972d..1e7ad3fc6b8 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -169,7 +169,7 @@ bool RemoveWallet(WalletContext& context, const std::shared_ptr<CWallet>& wallet
     WITH_LOCK(wallet->cs_wallet, wallet->WriteBestBlock());
 
     // Unregister with the validation interface which also drops shared pointers.
-    wallet->m_chain_notifications_handler.reset();
+    wallet->DisconnectChainNotifications();
     {
         LOCK(context.wallets_mutex);
         std::vector<std::shared_ptr<CWallet>>::iterator i = std::find(context.wallets.begin(), context.wallets.end(), wallet);
@@ -3117,7 +3117,7 @@ std::shared_ptr<CWallet> CWallet::CreateNew(WalletContext& context, const std::s
     walletInstance->TopUpKeyPool();
 
     if (chain && !AttachChain(walletInstance, *chain, /*rescan_required=*/false, error, warnings)) {
-        walletInstance->m_chain_notifications_handler.reset(); // Reset this pointer so that the wallet will actually be unloaded
+        walletInstance->DisconnectChainNotifications();
         return nullptr;
     }
 
@@ -3158,7 +3158,7 @@ std::shared_ptr<CWallet> CWallet::LoadExisting(WalletContext& context, const std
     walletInstance->TopUpKeyPool();
 
     if (chain && !AttachChain(walletInstance, *chain, rescan_required, error, warnings)) {
-        walletInstance->m_chain_notifications_handler.reset(); // Reset this pointer so that the wallet will actually be unloaded
+        walletInstance->DisconnectChainNotifications();
         return nullptr;
     }
 
@@ -4577,4 +4577,14 @@ std::optional<WalletTXO> CWallet::GetTXO(const COutPoint& outpoint) const
     }
     return it->second;
 }
+
+void CWallet::DisconnectChainNotifications()
+{
+    if (m_chain_notifications_handler) {
+        m_chain_notifications_handler->disconnect();
+        chain().waitForNotifications();
+        m_chain_notifications_handler.reset();
+    }
+}
+
 } // namespace wallet
diff --git a/src/wallet/wallet.h b/src/wallet/wallet.h
index e3d362360c4..fd4b368d781 100644
--- a/src/wallet/wallet.h
+++ b/src/wallet/wallet.h
@@ -1072,6 +1072,9 @@ public:
     //! Find the private key for the given key id from the wallet's descriptors, if available
     //! Returns nullopt when no descriptor has the key or if the wallet is locked.
     std::optional<CKey> GetKey(const CKeyID& keyid) const;
+
+    //! Disconnect chain notifications and wait for all notifications to be processed
+    void DisconnectChainNotifications();
 };
 
 /**