Move the txid duplicates check into BuildMerkleTree, where it can be done
much more efficiently (without needing to build a full txid set to detect
duplicates).
The previous version (using the std::set<uint256> to detect duplicates) was
also slightly too weak. A block mined with actual duplicate transactions
(which is invalid, due to the inputs of the duplicated transactions being
seen as double spends) would trigger the duplicates logic, resulting in the
block not being stored on disk, and rerequested. This change fixes that by
only triggering in the case of duplicated transactions that can actually
result in an identical merkle root.
Lots of people read the Bitcoin Core codebase to learn more about
crypto; better to warn about flaws explicitly so they don't blindly copy
the code for other uses and create broken systems.
Allows network wallets and other clients to see transactions that respend
a prevout already spent in an unconfirmed transaction in this node's mempool.
Knowledge of an attempted double-spend is of interest to recipients of the
first spend. In some cases, it will allow these recipients to withhold
goods or services upon being alerted of a double-spend that deprives them
of payment.
As before, respends are not added to the mempool.
Anti-Denial-of-Service-Attack provisions:
- Use a bloom filter to relay only one respend per mempool prevout
- Rate-limit respend relays to a default of 100 thousand bytes/minute
- Define tx2.IsEquivalentTo(tx1): equality when scriptSigs are not considered
- Do not relay these equivalent transactions
Remove an unused variable declaration in txmempool.cpp.
Use CFeeRate instead of an int64_t for quantities that are
fee-per-size.
Helps prevent unit-conversion mismatches between the wallet,
relaying, and mining code.
Size specifiers are no longer needed now that we use typesafe tinyformat
for string formatting, instead of the system's sprintf.
No functional changes.
This continues the work in #3735.
Amend to d5f1e72. It turns out that BerkelyDB was including inttypes.h
indirectly, so we cannot fix this with just macros.
Trivial commit: apply the following script to all .cpp and .h files:
# Middle
sed -i 's/"PRIx64"/x/g' "$1"
sed -i 's/"PRIu64"/u/g' "$1"
sed -i 's/"PRId64"/d/g' "$1"
# Initial
sed -i 's/PRIx64"/"x/g' "$1"
sed -i 's/PRIu64"/"u/g' "$1"
sed -i 's/PRId64"/"d/g' "$1"
# Trailing
sed -i 's/"PRIx64/x"/g' "$1"
sed -i 's/"PRIu64/u"/g' "$1"
sed -i 's/"PRId64/d"/g' "$1"
After this commit, `git grep` for PRI.64 should turn up nothing except
the defines in util.h.
contrib/devtools/fix-copyright-headers.py script to be able to perform this maintenance task with ease during the rest of the year, every year. Modifications to contrib/devtools/README.md to document what fix-copyright-headers.py does.
After the tinyformat switch sprintf() family functions support passing
actual std::string objects.
Remove unnecessary c_str calls (236 of them) in logging and formatting.
Use misc methods of avoiding unnecesary header includes.
Replace int typedefs with int##_t from stdint.h.
Replace PRI64[xdu] with PRI[xdu]64 from inttypes.h.
Normalize QT_VERSION ifs where possible.
Resolve some indirect dependencies as direct ones.
Remove extern declarations from .cpp files.
Previously bitcoin-qt's -debug transaction info was showing CTxOut([error])
It is valid for a scriptPubKey to be any size, for example simply
OP_RETURN is valid and can be used to destroy a TXOUT to mining fees.
Removed AreInputsStandard from CTransaction, made it a regular function in main.
Moved CTransaction::GetOutputFor to CCoinsViewCache.
Moved GetLegacySigOpCount and GetP2SHSigOpCount out of CTransaction into regular functions in main.
Moved GetValueIn and HaveInputs from CTransaction into CCoinsViewCache.
Moved AllowFree, ClientCheckInputs, CheckInputs, UpdateCoins, and CheckTransaction out of CTransaction and into main.
Moved IsStandard and IsFinal out of CTransaction and put them in main as IsStandardTx and IsFinalTx. Moved GetValueOut out of CTransaction into main. Moved CTxIn, CTxOut, and CTransaction into core.
Added minimum fee parameter to CTxOut::IsDust() temporarily until CTransaction is moved to core.h so that CTxOut needn't know about CTransaction.
jtimon