From 89940ae821bf2368792d76c93ceb697719fbf42d Mon Sep 17 00:00:00 2001
From: Hennadii Stepanov <32963518+hebasto@users.noreply.github.com>
Date: Thu, 12 Aug 2021 20:00:42 +0300
Subject: [PATCH] Merge bitcoin-core/gui#360: Unregister wallet notifications
 before unloading wallets

93cc53a2b27eeb05fe00b8bf17465037815473a1 gui: Unregister wallet notifications before unloading wallets (Russell Yanofsky)

Pull request description:

  This change was originally part of both bitcoin/bitcoin#10102 and bitcoin/bitcoin#19101 and is required for both because it avoids the IPC wallet implementation in bitcoin/bitcoin#10102 and the WalletContext implementation in bitcoin/bitcoin#19101 needing to deal with notification objects that have stale pointers to deleted wallets.

ACKs for top commit:
  promag:
    Code review ACK 93cc53a2b27eeb05fe00b8bf17465037815473a1.
  hebasto:
    ACK 93cc53a2b27eeb05fe00b8bf17465037815473a1

Tree-SHA512: 805f50a493291ad0f7c48725fbc5058d58ebbdb0770befd51d8aa241209a13f8a46f5982481336ab8338cdc83e9017668089a71deccf1587308e841cf8697825
---
 src/qt/bitcoin.cpp | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/src/qt/bitcoin.cpp b/src/qt/bitcoin.cpp
index ea773505ea..ca528bfeda 100644
--- a/src/qt/bitcoin.cpp
+++ b/src/qt/bitcoin.cpp
@@ -334,6 +334,17 @@ void BitcoinApplication::requestShutdown()
     window->setClientModel(nullptr);
     pollShutdownTimer->stop();
 
+#ifdef ENABLE_WALLET
+    // Delete wallet controller here manually, instead of relying on Qt object
+    // tracking (https://doc.qt.io/qt-5/objecttrees.html). This makes sure
+    // walletmodel m_handle_* notification handlers are deleted before wallets
+    // are unloaded, which can simplify wallet implementations. It also avoids
+    // these notifications having to be handled while GUI objects are being
+    // destroyed, making GUI code less fragile as well.
+    delete m_wallet_controller;
+    m_wallet_controller = nullptr;
+#endif // ENABLE_WALLET
+
     delete clientModel;
     clientModel = nullptr;