Merge f656165e9c into merged_master (Bitcoin PR #18772)

I'm gonna be honest, I largely just rewrote this one. It adds a "fee" field
to the RPC transaction output, which I replaced with a feemap which is
directly extracted from the transaction rather than computed implicitly
from inputs - outputs.

Removed a functional test that fee computations become impossible without
chain data, since in Elements there is no chain data lookup involved.

src/core_io.h

@@ -19,6 +19,7 @@ class CTransaction;
 struct CMutableTransaction;
 class uint256;
 class UniValue;
+class CTxUndo;
 
 // core_read.cpp
 CScript ParseScript(const std::string& s);
@@ -47,6 +48,6 @@ std::string EncodeHexTx(const CTransaction& tx, const int serializeFlags = 0);
 std::string SighashToStr(unsigned char sighash_type);
 void ScriptPubKeyToUniv(const CScript& scriptPubKey, UniValue& out, bool fIncludeHex);
 void ScriptToUniv(const CScript& script, UniValue& out, bool include_address);
-void TxToUniv(const CTransaction& tx, const uint256& hashBlock, UniValue& entry, bool include_hex = true, int serialize_flags = 0);
+void TxToUniv(const CTransaction& tx, const uint256& hashBlock, UniValue& entry, bool include_hex = true, int serialize_flags = 0, const CTxUndo* txundo = nullptr);
 
 #endif // BITCOIN_CORE_IO_H

src/core_write.cpp

@@ -13,7 +13,9 @@
 #include <script/standard.h>
 #include <serialize.h>
 #include <streams.h>
+#include <undo.h>
 #include <univalue.h>
+#include <util/check.h>
 #include <util/system.h>
 #include <util/strencodings.h>
 
@@ -225,7 +227,7 @@ void ScriptPubKeyToUniv(const CScript& scriptPubKey,
     }
 }
 
-void TxToUniv(const CTransaction& tx, const uint256& hashBlock, UniValue& entry, bool include_hex, int serialize_flags)
+void TxToUniv(const CTransaction& tx, const uint256& hashBlock, UniValue& entry, bool include_hex, int serialize_flags, const CTxUndo* txundo)
 {
     entry.pushKV("txid", tx.GetHash().GetHex());
     entry.pushKV("hash", tx.GetWitnessHash().GetHex());
@@ -241,13 +243,14 @@ void TxToUniv(const CTransaction& tx, const uint256& hashBlock, UniValue& entry,
     entry.pushKV("weight", GetTransactionWeight(tx));
     entry.pushKV("locktime", (int64_t)tx.nLockTime);
 
-    UniValue vin(UniValue::VARR);
+    UniValue vin{UniValue::VARR};
+
     for (unsigned int i = 0; i < tx.vin.size(); i++) {
         const CTxIn& txin = tx.vin[i];
         UniValue in(UniValue::VOBJ);
-        if (tx.IsCoinBase())
+        if (tx.IsCoinBase()) {
             in.pushKV("coinbase", HexStr(txin.scriptSig));
-        else {
+        } else {
             in.pushKV("txid", txin.prevout.hash.GetHex());
             in.pushKV("vout", (int64_t)txin.prevout.n);
             UniValue o(UniValue::VOBJ);
@@ -317,6 +320,7 @@ void TxToUniv(const CTransaction& tx, const uint256& hashBlock, UniValue& entry,
     }
     entry.pushKV("vin", vin);
 
+    CAmountMap fee_map{};
     UniValue vout(UniValue::VARR);
     for (unsigned int i = 0; i < tx.vout.size(); i++) {
         const CTxOut& txout = tx.vout[i];
@@ -350,6 +354,10 @@ void TxToUniv(const CTransaction& tx, const uint256& hashBlock, UniValue& entry,
             out.pushKV("valuecommitment", txout.nValue.GetHex());
         }
         if (g_con_elementsmode) {
+            if (txout.IsFee()) {
+                fee_map[txout.nAsset.GetAsset()] += txout.nValue.GetAmount();
+            }
+
             if (txout.nAsset.IsExplicit()) {
                 out.pushKV("asset", txout.nAsset.GetAsset().GetHex());
             } else {
@@ -369,6 +377,19 @@ void TxToUniv(const CTransaction& tx, const uint256& hashBlock, UniValue& entry,
     }
     entry.pushKV("vout", vout);
 
+    // ELEMENTS: add fee map rather than single fee. Unlike other areas of the RPC,
+    //  we do not look up labels here and will always use the asset hex (contrast
+    //  `AmountMapToUniv` in rpc/util.cpp. This is because this is a pure function
+    //  so we do not have access to `policyAsset` or `gAssetsDir`. (We will get link
+    //  errors if we try to use these.)
+    if (g_con_elementsmode) {
+        UniValue fee_obj(UniValue::VOBJ);
+        for(std::map<CAsset, CAmount>::const_iterator it = fee_map.begin(); it != fee_map.end(); ++it) {
+            fee_obj.pushKV(it->first.GetHex(), ValueFromAmount(it->second));
+        }
+        entry.pushKV("fee", fee_obj);
+    }
+
     if (!hashBlock.IsNull())
         entry.pushKV("blockhash", hashBlock.GetHex());
 

src/rpc/blockchain.cpp

@@ -203,16 +203,21 @@ UniValue blockToJSON(const CBlock& block, const CBlockIndex* tip, const CBlockIn
     result.pushKV("versionHex", strprintf("%08x", block.nVersion));
     result.pushKV("merkleroot", block.hashMerkleRoot.GetHex());
     UniValue txs(UniValue::VARR);
-    for(const auto& tx : block.vtx)
-    {
-        if(txDetails)
-        {
+    if (txDetails) {
+        CBlockUndo blockUndo;
+        const bool have_undo = !IsBlockPruned(blockindex) && UndoReadFromDisk(blockUndo, blockindex);
+        for (size_t i = 0; i < block.vtx.size(); ++i) {
+            const CTransactionRef& tx = block.vtx.at(i);
+            // coinbase transaction (i == 0) doesn't have undo data
+            const CTxUndo* txundo = (have_undo && i) ? &blockUndo.vtxundo.at(i - 1) : nullptr;
             UniValue objTx(UniValue::VOBJ);
-            TxToUniv(*tx, uint256(), objTx, true, RPCSerializationFlags());
+            TxToUniv(*tx, uint256(), objTx, true, RPCSerializationFlags(), txundo);
             txs.push_back(objTx);
         }
-        else
+    } else {
+        for (const CTransactionRef& tx : block.vtx) {
             txs.push_back(tx->GetHash().GetHex());
+        }
     }
     result.pushKV("tx", txs);
     result.pushKV("time", block.GetBlockTime());
@@ -1015,6 +1020,7 @@ static RPCHelpMan getblock()
                         {RPCResult::Type::OBJ, "", "",
                         {
                             {RPCResult::Type::ELISION, "", "The transactions in the format of the getrawtransaction RPC. Different from verbosity = 1 \"tx\" result"},
+                            {RPCResult::Type::NUM, "fee", "The transaction fee in " + CURRENCY_UNIT + ", omitted if block undo data is not available"},
                         }},
                     }},
                 }},

test/functional/rpc_blockchain.py

@@ -17,6 +17,7 @@ Tests correspond to code in rpc/blockchain.cpp.
 """
 from decimal import Decimal
 import http.client
+import os
 import subprocess
 
 from test_framework.blocktools import (
@@ -36,7 +37,9 @@ from test_framework.util import (
     assert_raises,
     assert_raises_rpc_error,
     assert_is_hash_string,
+    get_datadir_path,
 )
+from test_framework.wallet import MiniWallet
 
 
 class BlockchainTest(BitcoinTestFramework):
@@ -55,6 +58,7 @@ class BlockchainTest(BitcoinTestFramework):
         self._test_getblockheader()
         self._test_stopatheight()
         self._test_waitforblockheight()
+        self._test_getblock()
         assert self.nodes[0].verifychain(4, 0)
 
     def mine_chain(self):
@@ -348,6 +352,38 @@ class BlockchainTest(BitcoinTestFramework):
         assert_waitforheight(current_height)
         assert_waitforheight(current_height + 1)
 
+    def _test_getblock(self):
+        node = self.nodes[0]
+
+        miniwallet = MiniWallet(node)
+        miniwallet.generate(5)
+        node.generate(100)
+
+        fee_per_byte = Decimal('0.00000010')
+        fee_per_kb = 1000 * fee_per_byte
+
+        miniwallet.send_self_transfer(fee_rate=fee_per_kb, from_node=node)
+        blockhash = node.generate(1)[0]
+
+        self.log.info("Test that getblock with verbosity 1 doesn't include fee")
+        block = node.getblock(blockhash, 1)
+        assert 'fee' not in block['tx'][1]
+
+        self.log.info('Test that getblock with verbosity 2 includes expected fee')
+        block = node.getblock(blockhash, 2)
+        tx = block['tx'][1]
+        assert 'fee' in tx
+        asset_hex = node.getsidechaininfo()['pegged_asset']
+        assert_equal(tx['fee'], { asset_hex: tx['vsize'] * fee_per_byte })
+
+        self.log.info("Test that getblock with verbosity 2 still works with pruned Undo data")
+        datadir = get_datadir_path(self.options.tmpdir, 0)
+
+        def move_block_file(old, new):
+            old_path = os.path.join(datadir, self.chain, 'blocks', old)
+            new_path = os.path.join(datadir, self.chain, 'blocks', new)
+            os.rename(old_path, new_path)
+
 
 if __name__ == '__main__':
     BlockchainTest().main()

test/util/data/txcreatemultisig4_elements.json

@@ -28,5 +28,7 @@
             }
         }
     ],
+    "fee": {
+    },
     "hex": "01000000000001010000000000000000000000000000000000000000000000000000000000000000010000000005f5e1000017a9146edf12858999f0dae74f9c692e6694ee3621b2ac8700000000"
 }