Merge bitcoin/bitcoin#34112: rpc: [mempool] Remove erroneous Univalue integral casts

fab1f4b800d007bd4756b2519c64e1506ffe0d6c rpc: [mempool] Remove erroneous Univalue integral casts (MarcoFalke)

Pull request description:

  Casting without reason can only be confusing (because it is not needed), or wrong (because it does the wrong thing).

  For example, the added test that adds a positive chunk prioritization will fail:

  ```
  AssertionError: not(-1.94936096 == 41.000312)
  ```

  Fix all issues by removing the erroneous casts, and by adding a test to check against regressions.

ACKs for top commit:
  rkrux:
    tACK fab1f4b800d007bd4756b2519c64e1506ffe0d6c
  pablomartin4btc:
    ACK fab1f4b800d007bd4756b2519c64e1506ffe0d6c
  glozow:
    ACK fab1f4b800d007bd4756b2519c64e1506ffe0d6c

Tree-SHA512: b03c888ec07a8bdff25f7ded67f253b2a8edd83adf08980416e2ac8ac1b36ad952cc5828be833d19f64a55abab62d7a1c6f181bc5f1388ed08cc178b4aaec6ee

src/rpc/mempool.cpp

@@ -315,7 +315,7 @@ static std::vector<RPCResult> MempoolEntryDescription()
 void AppendChunkInfo(UniValue& all_chunks, FeePerWeight chunk_feerate, std::vector<const CTxMemPoolEntry *> chunk_txs)
 {
     UniValue chunk(UniValue::VOBJ);
-    chunk.pushKV("chunkfee", ValueFromAmount((int)chunk_feerate.fee));
+    chunk.pushKV("chunkfee", ValueFromAmount(chunk_feerate.fee));
     chunk.pushKV("chunkweight", chunk_feerate.size);
     UniValue chunk_txids(UniValue::VARR);
     for (const auto& chunk_tx : chunk_txs) {
@@ -383,7 +383,7 @@ static void entryToJSON(const CTxMemPool& pool, UniValue& info, const CTxMemPool
     fees.pushKV("modified", ValueFromAmount(e.GetModifiedFee()));
     fees.pushKV("ancestor", ValueFromAmount(ancestor_fees));
     fees.pushKV("descendant", ValueFromAmount(descendant_fees));
-    fees.pushKV("chunk", ValueFromAmount((int)feerate.fee));
+    fees.pushKV("chunk", ValueFromAmount(feerate.fee));
     info.pushKV("fees", std::move(fees));
 
     const CTransaction& tx = e.GetTx();

test/functional/mining_prioritisetransaction.py

@@ -36,6 +36,57 @@ class PrioritiseTransactionTest(BitcoinTestFramework):
             node.prioritisetransaction(txid, 0, -delta)
         assert_equal(node.getprioritisedtransactions(), {})
 
+    def test_large_fee_bump(self):
+        self.log.info("Test that a large fee delta is honoured")
+        tx = self.wallet.create_self_transfer()
+        txid = tx["txid"]
+        fee_delta = int(86 * COIN)  # large enough to not fit into (u)int32_t
+        self.nodes[0].prioritisetransaction(txid=txid, fee_delta=fee_delta)
+        assert_equal(
+            self.nodes[0].getprioritisedtransactions(),
+            {
+                txid: {
+                    "fee_delta": fee_delta,
+                    "in_mempool": False,
+                },
+            },
+        )
+        self.nodes[0].sendrawtransaction(tx["hex"])
+        expected_modified_fee = tx["fee"] + Decimal(fee_delta) / COIN
+        assert_equal(
+            self.nodes[0].getprioritisedtransactions(),
+            {
+                txid: {
+                    "fee_delta": fee_delta,
+                    "in_mempool": True,
+                    "modified_fee": int(expected_modified_fee * COIN),
+                },
+            },
+        )
+        # This transaction forms its own chunk.
+        mempool_entry = self.nodes[0].getrawmempool(verbose=True)[txid]
+        assert_equal(mempool_entry["fees"]["base"], tx["fee"])
+        assert_equal(mempool_entry["fees"]["modified"], expected_modified_fee)
+        assert_equal(mempool_entry["fees"]["ancestor"], expected_modified_fee)
+        assert_equal(mempool_entry["fees"]["descendant"], expected_modified_fee)
+        assert_equal(mempool_entry["fees"]["chunk"], expected_modified_fee)
+        assert_equal(mempool_entry["chunkweight"], mempool_entry["weight"])
+        append_chunk_info = self.nodes[0].getmempoolcluster(txid)
+        assert_equal(
+            append_chunk_info,
+            {
+                "clusterweight": mempool_entry["weight"],
+                "txcount": 1,
+                "chunks": [{
+                    "chunkfee": expected_modified_fee,
+                    "chunkweight": mempool_entry["weight"],
+                    "txs": [txid],
+                }],
+            },
+        )
+        self.generate(self.nodes[0], 1)
+        assert_equal(self.nodes[0].getprioritisedtransactions(), {})
+
     def test_replacement(self):
         self.log.info("Test tx prioritisation stays after a tx is replaced")
         conflicting_input = self.wallet.get_utxo()
@@ -175,6 +226,7 @@ class PrioritiseTransactionTest(BitcoinTestFramework):
         # Test `prioritisetransaction` invalid `fee_delta`
         assert_raises_rpc_error(-3, "JSON value of type string is not of expected type number", self.nodes[0].prioritisetransaction, txid=txid, fee_delta='foo')
 
+        self.test_large_fee_bump()
         self.test_replacement()
         self.test_diamond()