checkpoint: into main from release/2.5.2 @ 6e542f051ef6ad2aca5f16c76c5c0e97a6616e29

chia/_tests/core/mempool/test_mempool_manager.py

@@ -1136,7 +1136,7 @@ async def make_and_send_big_cost_sb(coin: Coin) -> None:
     skipped_due_to_eligible_coins = sum(
         1
         for line in caplog.text.split("\n")
-        if "DEBUG Exception while checking a mempool item for deduplication: Skipping transaction with eligible coin(s)"
+        if "Exception while checking a mempool item for deduplication: Skipping transaction with eligible coin(s)"
         in line
     )
     if num_skipped_items == PRIORITY_TX_THRESHOLD:

chia/_tests/core/mempool/test_singleton_fast_forward.py

@@ -381,6 +381,47 @@ async def prepare_and_test_singleton(
     return singleton, eve_coin_spend, inner_puzzle, remaining_coin
 
 
+@pytest.mark.anyio
+async def test_singleton_fast_forward_solo() -> None:
+    """
+    We don't allow a spend bundle with *only* fast forward spends, since those
+    are difficult to evict from the mempool. They would always be valid as long as
+    the singleton exists.
+    """
+    SINGLETON_AMOUNT = uint64(1337)
+    async with sim_and_client() as (sim, sim_client):
+        singleton, eve_coin_spend, inner_puzzle, _ = await prepare_and_test_singleton(
+            sim, sim_client, True, SINGLETON_AMOUNT, SINGLETON_AMOUNT
+        )
+        singleton_puzzle_hash = eve_coin_spend.coin.puzzle_hash
+        inner_puzzle_hash = inner_puzzle.get_tree_hash()
+        inner_conditions: list[list[Any]] = [
+            [ConditionOpcode.CREATE_COIN, inner_puzzle_hash, SINGLETON_AMOUNT],
+        ]
+        singleton_coin_spend, _ = make_singleton_coin_spend(eve_coin_spend, singleton, inner_puzzle, inner_conditions)
+        # spending the eve coin is not eligible for fast forward, so we need to make this spend first, to test FF
+        await make_and_send_spend_bundle(sim, sim_client, [singleton_coin_spend], aggsig=G2Element())
+        unspent_lineage_info = await sim_client.service.coin_store.get_unspent_lineage_info_for_puzzle_hash(
+            singleton_puzzle_hash
+        )
+        singleton_child, _ = await get_singleton_and_remaining_coins(sim)
+        assert singleton_child.amount == SINGLETON_AMOUNT
+        assert unspent_lineage_info == UnspentLineageInfo(
+            coin_id=singleton_child.name(),
+            coin_amount=singleton_child.amount,
+            parent_id=eve_coin_spend.coin.name(),
+            parent_amount=singleton.amount,
+            parent_parent_id=eve_coin_spend.coin.parent_coin_info,
+        )
+
+        inner_conditions = [[ConditionOpcode.CREATE_COIN, inner_puzzle_hash, 21]]
+        # this is a FF spend that isn't combined with any other spend. It's not allowed
+        singleton_coin_spend, _ = make_singleton_coin_spend(eve_coin_spend, singleton, inner_puzzle, inner_conditions)
+        status, error = await sim_client.push_tx(SpendBundle([singleton_coin_spend], G2Element()))
+        assert error is Err.INVALID_SPEND_BUNDLE
+        assert status == MempoolInclusionStatus.FAILED
+
+
 @pytest.mark.anyio
 @pytest.mark.parametrize("is_eligible_for_ff", [True, False])
 async def test_singleton_fast_forward_different_block(is_eligible_for_ff: bool) -> None:
@@ -544,7 +585,8 @@ async def test_singleton_fast_forward_same_block() -> None:
             singleton_coin_spend, _ = make_singleton_coin_spend(
                 eve_coin_spend, singleton, inner_puzzle, inner_conditions
             )
-            status, error = await sim_client.push_tx(SpendBundle([singleton_coin_spend], aggsig))
+            remaining_coin_spend = CoinSpend(remaining_coin, IDENTITY_PUZZLE, remaining_spend_solution)
+            status, error = await sim_client.push_tx(SpendBundle([singleton_coin_spend, remaining_coin_spend], aggsig))
             assert error is None
             assert status == MempoolInclusionStatus.SUCCESS
 

chia/full_node/mempool.py

@@ -612,7 +612,7 @@ async def create_bundle_from_mempool_items(
                 if self.mempool_info.max_block_clvm_cost - cost_sum < MIN_COST_THRESHOLD:
                     break
             except Exception as e:
-                log.debug(f"Exception while checking a mempool item for deduplication: {e}")
+                log.info(f"Exception while checking a mempool item for deduplication: {e}")
                 continue
         if processed_spend_bundles == 0:
             return None

chia/full_node/mempool_manager.py

@@ -474,6 +474,12 @@ async def validate_spend_bundle(
             # If you reach here it's probably because your program reveal doesn't match the coin's puzzle hash
             return Err.INVALID_SPEND_BUNDLE, None, []
 
+        # fast forward spends are only allowed when bundled with other, non-FF, spends
+        # in order to evict an FF spend, it must be associated with a normal
+        # spend that can be included in a block or invalidated some other way
+        if all([s.eligible_for_fast_forward for s in bundle_coin_spends.values()]):
+            return Err.INVALID_SPEND_BUNDLE, None, []
+
         removal_record_dict: dict[bytes32, CoinRecord] = {}
         removal_amount: int = 0
         removal_records = await get_coin_records(removal_names)