Merge #18244: rpc: fundrawtransaction and walletcreatefundedpsbt also lock manually selected coins

6d1f51343cf11b07cd401fbd0c5bc3603e185a0e [rpc] fundrawtransaction, walletcreatefundedpsbt lock manually selected coins (Sjors Provoost)

Pull request description:

  When using `fundrawtransaction` and `walletcreatefundedpsbt` with `lockUnspents`, it would only lock automatically selected coins, not manually selected coins. That doesn't make much sense to me if the goal is to prevent accidentally double-spending yourself before you broadcast a transaction.

  Note that when  creating a transaction, manually selected coins are automatic "unlocked" (or more accurately: the lock is ignored). Earlier versions of this PR introduced an error when a locked coin is manually selected, but this idea was abandoned after some discussion. An application that uses this RPC should either rely on automatic coin selection (with `lockUnspents`) or handle lock concurrency itself with manual coin selection. In particular it needs to make sure to avoid/pause calls with automatic coin selection between calling `lockunspent` and the subsequent spending RPC.

  See #7518 for historical background.

ACKs for top commit:
  meshcollider:
    Code review ACK 6d1f51343cf11b07cd401fbd0c5bc3603e185a0e
  fjahr:
    Code review ACK 6d1f51343cf11b07cd401fbd0c5bc3603e185a0e

Tree-SHA512: 8773c788d92f2656952e1beac147ba9956b8c5132d474e0880e4c89ff53642928b4cbfcd1cb3d17798b9284f02618a8830c93a9f7a4733e5bded96adff1d5d4d

5 files changed, 32 insertions, 6 deletions

diff --git a/doc/release-notes-18244.md b/doc/release-notes-18244.md
new file mode 100644
index 0000000000..625fbaf7a1
--- /dev/null
+++ b/doc/release-notes-18244.md
@@ -0,0 +1,7 @@
+Updated RPCs
+------------
+
+- `fundrawtransaction` and `walletcreatefundedpsbt` when used with the `lockUnspents`
+   argument now lock manually selected coins, in addition to automatically selected
+   coins. Note that locked coins are never used in automatic coin selection, but
+   can still be manually selected.
diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index 17512265b5..ab2d2a0157 100644
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -2061,6 +2061,7 @@ static UniValue lockunspent(const JSONRPCRequest& request)
                 "Temporarily lock (unlock=false) or unlock (unlock=true) specified transaction outputs.\n"
                 "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"
                 "Also see the listunspent call\n",
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index 199ae80095..34a5b7b8d2 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -2582,10 +2582,11 @@ bool CWallet::FundTransaction(CMutableTransaction& tx, CAmount& nFeeRet, int& nC
         if (!coinControl.IsSelected(txin.prevout)) {
             tx.vin.push_back(txin);
 
-            if (lockUnspents) {
-                LockCoin(txin.prevout);
-            }
         }
+        if (lockUnspents) {
+            LockCoin(txin.prevout);
+        }
+
     }
 
     return true;
diff --git a/test/functional/rpc_psbt.py b/test/functional/rpc_psbt.py
index f7f23bc8f4..1c7dc98d16 100755
--- a/test/functional/rpc_psbt.py
+++ b/test/functional/rpc_psbt.py
@@ -103,7 +103,16 @@ class PSBTTest(BitcoinTestFramework):
         final_tx = self.nodes[0].finalizepsbt(signed_tx)['hex']
         self.nodes[0].sendrawtransaction(final_tx)
 
-        # Get pubkeys
+        # Manually selected inputs can be locked:
+        assert_equal(len(self.nodes[0].listlockunspent()), 0)
+        utxo1 = self.nodes[0].listunspent()[0]
+        psbtx1 = self.nodes[0].walletcreatefundedpsbt([{"txid": utxo1['txid'], "vout": utxo1['vout']}], {self.nodes[2].getnewaddress():1}, 0,{"lockUnspents": True})["psbt"]
+        assert_equal(len(self.nodes[0].listlockunspent()), 1)
+
+        # Locks are ignored for manually selected inputs
+        self.nodes[0].walletcreatefundedpsbt([{"txid": utxo1['txid'], "vout": utxo1['vout']}], {self.nodes[2].getnewaddress():1}, 0)
+
+        # Create p2sh, p2wpkh, and p2wsh addresses
         pubkey0 = self.nodes[0].getaddressinfo(self.nodes[0].getnewaddress())['pubkey']
         pubkey1 = self.nodes[1].getaddressinfo(self.nodes[1].getnewaddress())['pubkey']
         pubkey2 = self.nodes[2].getaddressinfo(self.nodes[2].getnewaddress())['pubkey']
diff --git a/test/functional/wallet_basic.py b/test/functional/wallet_basic.py
index 71a1a3f4f6..c4db8e2119 100755
--- a/test/functional/wallet_basic.py
+++ b/test/functional/wallet_basic.py
@@ -135,11 +135,19 @@ class WalletTest(BitcoinTestFramework):
                                 self.nodes[2].lockunspent, False,
                                 [{"txid": unspent_0["txid"], "vout": 999}])
 
-        # An output should be unlocked when spent
+        # The lock on a manually selected output is ignored
         unspent_0 = self.nodes[1].listunspent()[0]
         self.nodes[1].lockunspent(False, [unspent_0])
         tx = self.nodes[1].createrawtransaction([unspent_0], { self.nodes[1].getnewaddress() : 1 })
-        tx = self.nodes[1].fundrawtransaction(tx)['hex']
+        self.nodes[1].fundrawtransaction(tx,{"lockUnspents": True})
+
+        # fundrawtransaction can lock an input
+        self.nodes[1].lockunspent(True, [unspent_0])
+        assert_equal(len(self.nodes[1].listlockunspent()), 0)
+        tx = self.nodes[1].fundrawtransaction(tx,{"lockUnspents": True})['hex']
+        assert_equal(len(self.nodes[1].listlockunspent()), 1)
+
+        # Send transaction
         tx = self.nodes[1].signrawtransactionwithwallet(tx)["hex"]
         self.nodes[1].sendrawtransaction(tx)
         assert_equal(len(self.nodes[1].listlockunspent()), 0)