Merge bitcoin#19847: rpc, refactor: Avoid duplicate set lookup in gettxoutproof

52fc399 rpc: Reject empty txids in gettxoutproof (João Barbosa)
73dc19a rpc, refactor: Avoid duplicate set lookup in gettxoutproof (João Barbosa)

Pull request description:

ACKs for top commit:
  jonasschnelli:
    code review ACK 52fc399

Tree-SHA512: 76b18e5235e8b2d394685515a4a60335666eeb0f6b31c1d397f7db2fbe681bc817b8cd3e8f6708b9dacd6113e4e1d94837072cae27834b8a1a22d2717db8191e

Author: jonasschnelli

src/rpc/rawtransaction.cpp

@@ -591,16 +591,15 @@ static UniValue gettxoutproof(const JSONRPCRequest& request)
     }.Check(request);
 
     std::set<uint256> setTxids;
-    uint256 oneTxid;
     UniValue txids = request.params[0].get_array();
+    if (txids.empty()) {
+        throw JSONRPCError(RPC_INVALID_PARAMETER, "Parameter 'txids' cannot be empty");
+    }
     for (unsigned int idx = 0; idx < txids.size(); idx++) {
-        const UniValue& txid = txids[idx];
-        uint256 hash(ParseHashV(txid, "txid"));
-        if (setTxids.count(hash)) {
-            throw JSONRPCError(RPC_INVALID_PARAMETER, std::string("Invalid parameter, duplicated txid: ")+txid.get_str());
+        auto ret = setTxids.insert(ParseHashV(txids[idx], "txid"));
+        if (!ret.second) {
+            throw JSONRPCError(RPC_INVALID_PARAMETER, std::string("Invalid parameter, duplicated txid: ") + txids[idx].get_str());
         }
-       setTxids.insert(hash);
-       oneTxid = hash;
     }
 
     CBlockIndex* pblockindex = nullptr;
@@ -636,7 +635,7 @@ static UniValue gettxoutproof(const JSONRPCRequest& request)
     LOCK(cs_main);
 
     if (pblockindex == nullptr) {
-        const CTransactionRef tx = GetTransaction(/* block_index */ nullptr, /* mempool */ nullptr, oneTxid, Params().GetConsensus(), hashBlock);
+        const CTransactionRef tx = GetTransaction(/* block_index */ nullptr, /* mempool */ nullptr, *setTxids.begin(), Params().GetConsensus(), hashBlock);
         if (!tx || hashBlock.IsNull()) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Transaction not yet in block");
         }

test/functional/rpc_txoutproof.py

@@ -82,7 +82,7 @@ def run_test(self):
         # We can't get a proof if we specify transactions from different blocks
         assert_raises_rpc_error(-5, "Not all transactions found in specified or retrieved block", self.nodes[0].gettxoutproof, [txid1, txid3])
         # Test empty list
-        assert_raises_rpc_error(-5, "Transaction not yet in block", self.nodes[0].gettxoutproof, [])
+        assert_raises_rpc_error(-8, "Parameter 'txids' cannot be empty", self.nodes[0].gettxoutproof, [])
         # Test duplicate txid
         assert_raises_rpc_error(-8, 'Invalid parameter, duplicated txid', self.nodes[0].gettxoutproof, [txid1, txid1])