Merge bitcoin/bitcoin#20833: rpc/validation: enable packages through testmempoolaccept

13650fe2e527bf0cf5d977bf5f3f1563b853ecdc [policy] detect unsorted packages (glozow)
9ef643e21b44f99f4bce54077788d0ad4d81f7cd [doc] add release note for package testmempoolaccept (glozow)
c4259f4b7ee23ef6e0ec82c5d5b9dfa9cadd5bed [test] functional test for packages in RPCs (glozow)
9ede34a6f20378e86c5289ebd20dd394a5915123 [rpc] allow multiple txns in testmempoolaccept (glozow)
ae8e6df709ff3d52b8e9918e09cacb64f83ae379 [policy] limit package sizes (glozow)
c9e1a26d1f17c8b98632b7796ffa8f8788b5a83c [fuzz] add ProcessNewPackage call in tx_pool fuzzer (glozow)
363e3d916cc036488783bb4bdcfdd3665aecf711 [test] unit tests for ProcessNewPackage (glozow)
cd9a11ac96c01e200d0086b2f011f4a614f5a705 [test] make submit optional in CreateValidMempoolTransaction (glozow)
2ef187941db439c5b3e529f08b6ab153ff061fc5 [validation] package validation for test accepts (glozow)
578148ded62828a9820398165c41670f4dbb523d [validation] explicit Success/Failure ctors for MempoolAcceptResult (glozow)
b88d77aec5e7bef5305a668d15031351c0548b4d [policy] Define packages (glozow)
249f43f3cc52b0ffdf2c47aad95ba9d195f6a45e [refactor] add option to disable RBF (glozow)
897e348f5987eadd8559981a973c045c471b3ad8 [coins/mempool] extend CCoinsViewMemPool to track temporary coins (glozow)
42cf8b25df07c45562b7210e0e15c3fd5edb2c11 [validation] make CheckSequenceLocks context-free (glozow)

Pull request description:

  This PR enables validation dry-runs of packages through the `testmempoolaccept` RPC. The expectation is that the results returned from `testmempoolaccept` are what you'd get from test-then-submitting each transaction individually, in that order (this means the package is expected to be sorted in topological order, for now at least). The validation is also atomic: in the case of failure, it immediately halts and may return "unfinished" `MempoolAcceptResult`s for transactions that weren't fully validated. The API for 1 transaction stays the same.

  **Motivation:**
  - This allows you to test validity for transaction chains (e.g. with multiple spending paths and where you don't want to broadcast yet); closes #18480.
  - It's also a first step towards package validation in a minimally invasive way.
  - The RPC commit happens to close #21074 by clarifying the "allowed" key.

  There are a few added restrictions on the packages, mostly to simplify the logic for areas that aren't critical to main package use cases:
  - No package can have conflicts, i.e. none of them can spend the same inputs, even if it would be a valid BIP125 replacement.
  - The package cannot conflict with the mempool, i.e. RBF is disabled.
  - The total count of the package cannot exceed 25 (the default descendant count limit), and total size cannot exceed 101KvB (the default descendant size limit).

  If you're looking for review comments and github isn't loading them, I have a gist compiling some topics of discussion [here](https://gist.github.com/glozow/c3acaf161c95bba491fce31585b2aaf7)

ACKs for top commit:
  laanwj:
    Code review re-ACK 13650fe2e527bf0cf5d977bf5f3f1563b853ecdc
  jnewbery:
    Code review ACK 13650fe2e527bf0cf5d977bf5f3f1563b853ecdc
  ariard:
    ACK 13650fe

Tree-SHA512: 8c5cbfa91a6c714e1c8710bb281d5ff1c5af36741872a7c5df6b24874d6272b4a09f816cb8a4c7de33ef8e1c2a2c252c0df5105b7802f70bc6ff821ed7cc1a2f

1 files changed, 10 insertions, 0 deletions

diff --git a/src/test/fuzz/tx_pool.cpp b/src/test/fuzz/tx_pool.cpp
index ad11f2c5f2..bab34ea340 100644
--- a/src/test/fuzz/tx_pool.cpp
+++ b/src/test/fuzz/tx_pool.cpp
@@ -219,6 +219,16 @@ FUZZ_TARGET_INIT(tx_pool_standard, initialize_tx_pool)
         RegisterSharedValidationInterface(txr);
         const bool bypass_limits = fuzzed_data_provider.ConsumeBool();
         ::fRequireStandard = fuzzed_data_provider.ConsumeBool();
+
+        // Make sure ProcessNewPackage on one transaction works and always fully validates the transaction.
+        // The result is not guaranteed to be the same as what is returned by ATMP.
+        const auto result_package = WITH_LOCK(::cs_main,
+                                    return ProcessNewPackage(node.chainman->ActiveChainstate(), tx_pool, {tx}, true));
+        auto it = result_package.m_tx_results.find(tx->GetWitnessHash());
+        Assert(it != result_package.m_tx_results.end());
+        Assert(it->second.m_result_type == MempoolAcceptResult::ResultType::VALID ||
+               it->second.m_result_type == MempoolAcceptResult::ResultType::INVALID);
+
         const auto res = WITH_LOCK(::cs_main, return AcceptToMemoryPool(chainstate, tx_pool, tx, bypass_limits));
         const bool accepted = res.m_result_type == MempoolAcceptResult::ResultType::VALID;
         SyncWithValidationInterfaceQueue();