Merge bitcoin/bitcoin#23065: Allow UTXO locks to be written to wallet DB

d96b000e94d72d041689c5c47e374df2ebc0e011 Make GUI UTXO lock/unlock persistent (Samuel Dobson)
077154fe698f5556ad6e26ef49c9024c2f07ff68 Add release note for lockunspent change (Samuel Dobson)
719ae927dcdb60c0f9902fa79796256035228c4e Update lockunspent tests for lock persistence (Samuel Dobson)
f13fc16295c19a156f2974d2d73fba56d52fc161 Allow lockunspent to store the lock in the wallet DB (Samuel Dobson)
c52789365e5dbcb25aa5f1775de4d318da79e5a7 Allow locked UTXOs to be store in the wallet database (Samuel Dobson)

Pull request description:

  Addresses and closes #22368

  As per that issue (and its predecessor #14907), there seems to be some interest in allowing unspent outputs to be locked persistently. This PR does so by adding a flag to lockunspent to store the change in the wallet database. Defaults to false, so there is no change in default behaviour.

  Edit: GUI commit changes default behaviour. UTXOs locked/unlocked via the GUI are now persistent.

ACKs for top commit:
  achow101:
    ACK d96b000e94d72d041689c5c47e374df2ebc0e011
  kristapsk:
    ACK d96b000e94d72d041689c5c47e374df2ebc0e011
  lsilva01:
    Tested ACK https://github.com/bitcoin/bitcoin/pull/23065/commits/d96b000e94d72d041689c5c47e374df2ebc0e011 on Ubuntu 20.04
  prayank23:
    ACK https://github.com/bitcoin/bitcoin/pull/23065/commits/d96b000e94d72d041689c5c47e374df2ebc0e011

Tree-SHA512: 957a5bbfe7f763036796906ccb1598feb6c14c5975838be1ba24a198840bf59e83233165cb112cebae909b6b25bf27275a4d7fa425923ef6c788ff671d7a89a8

1 files changed, 22 insertions, 7 deletions

diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index 77757e79a3..c101f6560d 100644
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -2140,8 +2140,9 @@ static RPCHelpMan lockunspent()
                 "If no transaction outputs are specified when unlocking then all current locked transaction outputs are unlocked.\n"
                 "A locked transaction output will not be chosen by automatic coin selection, when spending bitcoins.\n"
                 "Manually selected coins are automatically unlocked.\n"
-                "Locks are stored in memory only. Nodes start with zero locked outputs, and the locked output list\n"
-                "is always cleared (by virtue of process exit) when a node stops or fails.\n"
+                "Locks are stored in memory only, unless persistent=true, in which case they will be written to the\n"
+                "wallet database and loaded on node start. Unwritten (persistent=false) locks are always cleared\n"
+                "(by virtue of process exit) when a node stops or fails. Unlocking will clear both persistent and not.\n"
                 "Also see the listunspent call\n",
                 {
                     {"unlock", RPCArg::Type::BOOL, RPCArg::Optional::NO, "Whether to unlock (true) or lock (false) the specified transactions"},
@@ -2155,6 +2156,7 @@ static RPCHelpMan lockunspent()
                             },
                         },
                     },
+                    {"persistent", RPCArg::Type::BOOL, RPCArg::Default{false}, "Whether to write/erase this lock in the wallet database, or keep the change in memory only. Ignored for unlocking."},
                 },
                 RPCResult{
                     RPCResult::Type::BOOL, "", "Whether the command was successful or not"
@@ -2168,6 +2170,8 @@ static RPCHelpMan lockunspent()
             + HelpExampleCli("listlockunspent", "") +
             "\nUnlock the transaction again\n"
             + HelpExampleCli("lockunspent", "true \"[{\\\"txid\\\":\\\"a08e6907dbbd3d809776dbfc5d82e371b764ed838b5655e72f463568df1aadf0\\\",\\\"vout\\\":1}]\"") +
+            "\nLock the transaction persistently in the wallet database\n"
+            + HelpExampleCli("lockunspent", "false \"[{\\\"txid\\\":\\\"a08e6907dbbd3d809776dbfc5d82e371b764ed838b5655e72f463568df1aadf0\\\",\\\"vout\\\":1}]\" true") +
             "\nAs a JSON-RPC call\n"
             + HelpExampleRpc("lockunspent", "false, \"[{\\\"txid\\\":\\\"a08e6907dbbd3d809776dbfc5d82e371b764ed838b5655e72f463568df1aadf0\\\",\\\"vout\\\":1}]\"")
                 },
@@ -2186,9 +2190,13 @@ static RPCHelpMan lockunspent()
 
     bool fUnlock = request.params[0].get_bool();
 
+    const bool persistent{request.params[2].isNull() ? false : request.params[2].get_bool()};
+
     if (request.params[1].isNull()) {
-        if (fUnlock)
-            pwallet->UnlockAllCoins();
+        if (fUnlock) {
+            if (!pwallet->UnlockAllCoins())
+                throw JSONRPCError(RPC_WALLET_ERROR, "Unlocking coins failed");
+        }
         return true;
     }
 
@@ -2239,17 +2247,24 @@ static RPCHelpMan lockunspent()
             throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, expected locked output");
         }
 
-        if (!fUnlock && is_locked) {
+        if (!fUnlock && is_locked && !persistent) {
             throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, output already locked");
         }
 
         outputs.push_back(outpt);
     }
 
+    std::unique_ptr<WalletBatch> batch = nullptr;
+    // Unlock is always persistent
+    if (fUnlock || persistent) batch = std::make_unique<WalletBatch>(pwallet->GetDatabase());
+
     // Atomically set (un)locked status for the outputs.
     for (const COutPoint& outpt : outputs) {
-        if (fUnlock) pwallet->UnlockCoin(outpt);
-        else pwallet->LockCoin(outpt);
+        if (fUnlock) {
+            if (!pwallet->UnlockCoin(outpt, batch.get())) throw JSONRPCError(RPC_WALLET_ERROR, "Unlocking coin failed");
+        } else {
+            if (!pwallet->LockCoin(outpt, batch.get())) throw JSONRPCError(RPC_WALLET_ERROR, "Locking coin failed");
+        }
     }
 
     return true;