Merge #14880: 0.17: Backport #14453

dcb032dcdf qa: Ensure wallet unload during walletpassphrase timeout (João Barbosa)
75b5d8c4ea rpc: Fix wallet unload during walletpassphrase timeout (João Barbosa)

Pull request description:

  Backport #14453 to 0.17

Tree-SHA512: fce0adccbb07b6635bb773a71beb4a9b814bceb77bbe7bbc5bcb7d151aabb1148c791622f58c990afe202012ca1971cd466cb536fc6f37e22cdc58738720b593

2 files changed, 21 insertions, 8 deletions

diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index 6400b4470f..193da76551 100644
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -2546,13 +2546,6 @@ static UniValue keypoolrefill(const JSONRPCRequest& request)
 }
 
 
-static void LockWallet(CWallet* pWallet)
-{
-    LOCK(pWallet->cs_wallet);
-    pWallet->nRelockTime = 0;
-    pWallet->Lock();
-}
-
 static UniValue walletpassphrase(const JSONRPCRequest& request)
 {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
@@ -2622,7 +2615,18 @@ static UniValue walletpassphrase(const JSONRPCRequest& request)
     pwallet->TopUpKeyPool();
 
     pwallet->nRelockTime = GetTime() + nSleepTime;
-    RPCRunLater(strprintf("lockwallet(%s)", pwallet->GetName()), std::bind(LockWallet, pwallet), nSleepTime);
+
+    // Keep a weak pointer to the wallet so that it is possible to unload the
+    // wallet before the following callback is called. If a valid shared pointer
+    // is acquired in the callback then the wallet is still loaded.
+    std::weak_ptr<CWallet> weak_wallet = wallet;
+    RPCRunLater(strprintf("lockwallet(%s)", pwallet->GetName()), [weak_wallet] {
+        if (auto shared_wallet = weak_wallet.lock()) {
+            LOCK(shared_wallet->cs_wallet);
+            shared_wallet->Lock();
+            shared_wallet->nRelockTime = 0;
+        }
+    }, nSleepTime);
 
     return NullUniValue;
 }
diff --git a/test/functional/wallet_multiwallet.py b/test/functional/wallet_multiwallet.py
index 435821ec48..f53172639c 100755
--- a/test/functional/wallet_multiwallet.py
+++ b/test/functional/wallet_multiwallet.py
@@ -8,6 +8,7 @@ Verify that a bitcoind node can load multiple wallet files
 """
 import os
 import shutil
+import time
 
 from test_framework.test_framework import BitcoinTestFramework
 from test_framework.test_node import ErrorMatch
@@ -262,7 +263,15 @@ class MultiWalletTest(BitcoinTestFramework):
         assert 'w1' not in self.nodes[0].listwallets()
 
         # Successfully unload the wallet referenced by the request endpoint
+        # Also ensure unload works during walletpassphrase timeout
+        wallets = node.listwallets()
+        w2.encryptwallet('test')
+        self.restart_node(0, ['-wallet={}'.format(wallet) for wallet in wallets])
+        w1 = node.get_wallet_rpc(wallet_names[0])
+        w2 = node.get_wallet_rpc(wallet_names[1])
+        w2.walletpassphrase('test', 1)
         w2.unloadwallet()
+        time.sleep(1.1)
         assert 'w2' not in self.nodes[0].listwallets()
 
         # Successfully unload all wallets