* Don't rely on UTXO set in CheckCanLock
The UTXO set only works for TXs in the mempool and won't work when we try
to retroactively lock unlocked TXs from blocks.
This is safe as ProcessTx is only called when a TX was accepted into the
mempool or connected in a block, which means that all input checks were
good.
* Rename RetryLockMempoolTxs to RetryLockTxs and let it retry connected TXs
* Instead of manually calling ProcessTx, let SyncTransaction handle all cases
SyncTransaction is called from AcceptToMemoryPool and when transactions got
connected in a block. So this is the time we want to run TXs through
ProcessTx. This also enables retroactive signing of TXs that were unknown
before a new block appeared.
* Test retroactive signing and safe TXs in LLMQ ChainLocks tests
* Also test for retroactive signing of chained TXs
* Honor lockedParentTx when looking for TXs to retry signing
* Stop scanning for TXs to retry after a depth of 6
* Generate 6 block to avoid retroactive signing overloading Travis
* Avoid retroactive signing
* Don't rely on NewPoWValidBlock and use SyncTransaction to build blockTxs
NewPoWValidBlock is not guaranteed to be called when blocks come in fast.
When a block is accepted in AcceptBlock, NewPoWValidBlock is only called
when the new block is a successor of the currently active tip. This is not
the case when after the first block a second block is accepted immediately
as the first block is not connected yet.
This might be a bug actually in the handling of NewPoWValidBlock, so we
might need to check/fix this later, but currently I prefer to not touch
that part.
Instead, we now use SyncTransaction to gather TXs for blockTxs. This works
because SyncTransaction is called for all transactions in a freshly
connected block in one go. The call also happens before UpdatedBlockTip is
called, so it's fine with the existing logic.
* Use tx.IsCoinBase() instead of checking index 0
Also check for empty vin.
* Remove unused parameters from CInstantSendManager::ProcessTx
* Pass txHash in CheckCanLock by reference instead of pointer
* Dont' allow locking of TXs without inputs
* Remove unused local variable nInstantSendConfirmationsRequired
* Don't subtract 1 from nInstantSendConfirmationsRequired
This was necessary in the old system but is not necessary in the new system.
It also prevented proper retroactive signing of chained TXs in regtest as
it resulted in child TXs to return true immediately for CheckCanLock when
it should actually have waited for the parent TX to become locked first.
* Access chainActive.Height() while cs_main is locked
* Properly read and write lastChainLockBlock
"pindex" is NOT the chainlocked block after the while loop finishes. We
must use the pindex (renamed to pindexChainLock now) given on method entry.
Also, the GetLastChainLockBlock() result was not assigned to,
lastChainLockBlock which resulted in the while loop to run unnecessarily
long.
* Generalize filtering in NewPoWValidBlock and SyncTransaction
We're actually interested in all TXs that have inputs, so no need to
explicitly check for tx types.
* Use tx.IsCoinBase() instead of checking for index 0
* Handle cases where a TX is not received yet in wait_for_instantlock
* Wait on all nodes for the locks
Otherwise we end up with the sender having it locked but other nodes
not yet, failing the test.
* Fix LogPrintf call in CChainLocksHandler::DoInvalidateBlock
