Merge bitcoin/bitcoin#26280: rpc: Return coinbase flag in scantxoutset

fa08663 rpc: Return coinbase flag in scantxoutset (MacroFake)

Pull request description:

  I guess it can't hurt to return this for someone that wants to know it

ACKs for top commit:
  aureleoules:
    ACK fa08663
  shaavan:
    ACK fa08663

Tree-SHA512: 04c554b3ed9877bab93ffcf0c1a4430cd41b30c5f4f3bf462a518fc8b3d68832dd85a29e81bd805eaa16e987856933d7a888a8c126f670bb2844bbd5ca1bf902

Author: fanquake

src/rpc/blockchain.cpp

@@ -2069,6 +2069,7 @@ static RPCHelpMan scantxoutset()
                         {RPCResult::Type::STR_HEX, "scriptPubKey", "The script key"},
                         {RPCResult::Type::STR, "desc", "A specialized descriptor for the matched scriptPubKey"},
                         {RPCResult::Type::STR_AMOUNT, "amount", "The total amount in " + CURRENCY_UNIT + " of the unspent output"},
+                        {RPCResult::Type::BOOL, "coinbase", "Whether this is a coinbase output"},
                         {RPCResult::Type::NUM, "height", "Height of the unspent transaction output"},
                     }},
                 }},
@@ -2172,6 +2173,7 @@ static RPCHelpMan scantxoutset()
             unspent.pushKV("scriptPubKey", HexStr(txo.scriptPubKey));
             unspent.pushKV("desc", descriptors[txo.scriptPubKey]);
             unspent.pushKV("amount", ValueFromAmount(txo.nValue));
+            unspent.pushKV("coinbase", coin.IsCoinBase());
             unspent.pushKV("height", (int32_t)coin.nHeight);
 
             unspents.push_back(unspent);

test/functional/rpc_scantxoutset.py

@@ -33,6 +33,9 @@ def run_test(self):
         self.wallet = MiniWallet(self.nodes[0])
         self.wallet.rescan_utxos()
 
+        self.log.info("Test if we find coinbase outputs.")
+        assert_equal(sum(u["coinbase"] for u in self.nodes[0].scantxoutset("start", [self.wallet.get_descriptor()])["unspents"]), 49)
+
         self.log.info("Create UTXOs...")
         pubk1, spk_P2SH_SEGWIT, addr_P2SH_SEGWIT = getnewdestination("p2sh-segwit")
         pubk2, spk_LEGACY, addr_LEGACY = getnewdestination("legacy")