Inside Bitcoin

251-------------------------
252
253- The `testnet` field in `bitcoin-cli -getinfo` has been renamed to
254  `chain` and now returns the current network name as defined in BIP70
255  (main, test, regtest). (#15566)
256
257Low-level changes
258=================
259
260RPC
261---
262
263- `getblockchaininfo` no longer returns a `bip9_softforks` object.
264  Instead, information has been moved into the `softforks` object and
265  an additional `type` field describes how Bitcoin Core determines
266  whether that soft fork is active (e.g. BIP9 or BIP90).  See the RPC
267  help for details. (#16060)
268
269- `getblocktemplate` no longer returns a `rules` array containing `CSV`
270  and `segwit` (the BIP9 deployments that are currently in active
271  state). (#16060)
272
273- `getrpcinfo` now returns a `logpath` field with the path to
274  `debug.log`. (#15483)
275
276Tests
277-----
278
279- The regression test chain enabled by the `-regtest` command line flag
280  now requires transactions to not violate standard policy by default.
281  This is the same default used for mainnet and makes it easier to test
282  mainnet behavior on regtest. Note that the testnet still allows
283  non-standard txs by default and that the policy can be locally
284  adjusted with the `-acceptnonstdtxn` command line flag for both test
285  chains. (#15891)
286
287Configuration
288------------
289
290- A setting specified in the default section but not also specified in a
291  network-specific section (e.g. testnet) will now produce an error
292  preventing startup instead of just a warning unless the network is
293  mainnet.  This prevents settings intended for mainnet from being
294  applied to testnet or regtest. (#15629)
295
296- On platforms supporting `thread_local`, log lines can be prefixed with
297  the name of the thread that caused the log. To enable this behavior,
298  use `-logthreadnames=1`. (#15849)
299
300Network
301-------
302
303- When fetching a transaction announced by multiple peers, previous versions of
304  Bitcoin Core would sequentially attempt to download the transaction from each
305  announcing peer until the transaction is received, in the order that those
306  peers' announcements were received.  In this release, the download logic has
307  changed to randomize the fetch order across peers and to prefer sending
308  download requests to outbound peers over inbound peers. This fixes an issue
309  where inbound peers could prevent a node from getting a transaction.
310  (#14897, #15834)
311
312- If a Tor hidden service is being used, Bitcoin Core will be bound to
313  the standard port 8333 even if a different port is configured for
314  clearnet connections.  This prevents leaking node identity through use
315  of identical non-default port numbers. (#15651)
316
317Mempool and transaction relay
318-----------------------------
319
320- Allows one extra single-ancestor transaction per package.  Previously,
321  if a transaction in the mempool had 25 descendants, or it and all of
322  its descendants were over 101,000 vbytes, any newly-received
323  transaction that was also a descendant would be ignored.  Now, one
324  extra descendant will be allowed provided it is an immediate
325  descendant (child) and the child's size is 10,000 vbytes or less.
326  This makes it possible for two-party contract protocols such as
327  Lightning Network to give each participant an output they can spend
328  immediately for Child-Pays-For-Parent (CPFP) fee bumping without
329  allowing one malicious participant to fill the entire package and thus
330  prevent the other participant from spending their output. (#15681)
331
332- Transactions with outputs paying v1 to v16 witness versions (future
333  segwit versions) are now accepted into the mempool, relayed, and
334  mined.  Attempting to spend those outputs remains forbidden by policy
335  ("non-standard").  When this change has been widely deployed, wallets
336  and services can accept any valid bech32 Bitcoin address without
337  concern that transactions paying future segwit versions will become
338  stuck in an unconfirmed state. (#15846)
339
340- Legacy transactions (transactions with no segwit inputs) must now be
341  sent using the legacy encoding format, enforcing the rule specified in
342  BIP144.  (#14039)
343
344Wallet
345------
346
347- When in pruned mode, a rescan that was triggered by an `importwallet`,
348  `importpubkey`, `importaddress`, or `importprivkey` RPC will only fail
349  when blocks have been pruned. Previously it would fail when `-prune`
350  has been set.  This change allows setting `-prune` to a high value
351  (e.g. the disk size) without the calls to any of the import RPCs
352  failing until the first block is pruned. (#15870)
353
354- When creating a transaction with a fee above `-maxtxfee` (default 0.1
355  BTC), the RPC commands `walletcreatefundedpsbt` and
356  `fundrawtransaction` will now fail instead of rounding down the fee.
357  Be aware that the `feeRate` argument is specified in BTC per 1,000
358  vbytes, not satoshi per vbyte. (#16257)
359
360- A new wallet flag `avoid_reuse` has been added (default off). When
361  enabled, a wallet will distinguish between used and unused addresses,
362  and default to not use the former in coin selection.  When setting
363  this flag on an existing wallet, rescanning the blockchain is required
364  to correctly mark previously used destinations.  Together with "avoid
365  partial spends" (added in Bitcoin Core v0.17.0), this can eliminate a
366  serious privacy issue where a malicious user can track spends by
367  sending small payments to a previously-paid address that would then
368  be included with unrelated inputs in future payments. (#13756)
369
370Build system changes
371--------------------
372
373- Python >=3.5 is now required by all aspects of the project. This
374  includes the build systems, test framework and linters. The previously
375  supported minimum (3.4), was EOL in March 2019. (#14954)
376
377- The minimum supported miniUPnPc API version is set to 10. This keeps
378  compatibility with Ubuntu 16.04 LTS and Debian 8 `libminiupnpc-dev`
379  packages. Please note, on Debian this package is still vulnerable to
380  [CVE-2017-8798](https://security-tracker.debian.org/tracker/CVE-2017-8798)
381  (in jessie only) and
382  [CVE-2017-1000494](https://security-tracker.debian.org/tracker/CVE-2017-1000494)
383  (both in jessie and in stretch). (#15993)
384
3850.19.0 change log
386=================
387
388### Consensus
389- #16128 Delete error-prone CScript constructor only used with FindAndDelete (instagibbs)
390- #16060 Bury bip9 deployments (jnewbery)
391
392### Policy
393- #15557 Enhance `bumpfee` to include inputs when targeting a feerate (instagibbs)
394- #15846 Make sending to future native witness outputs standard (sipa)
395
396### Block and transaction handling
397- #15632 Remove ResendWalletTransactions from the Validation Interface (jnewbery)
398- #14121 Index for BIP 157 block filters (jimpo)
399- #15141 Rewrite DoS interface between validation and net_processing (sdaftuar)
400- #15880 utils and libraries: Replace deprecated Boost Filesystem functions (hebasto)
401- #15971 validation: Add compile-time checking for negative locking requirement in LimitValidationInterfaceQueue (practicalswift)
402- #15999 init: Remove dead code in LoadChainTip (MarcoFalke)
403- #16015 validation: Hold cs_main when reading chainActive in RewindBlockIndex (practicalswift)
404- #16056 remove unused magic number from consistency check (instagibbs)
405- #16171 Remove -mempoolreplacement to prevent needless block prop slowness (TheBlueMatt)
406- #15894 Remove duplicated "Error: " prefix in logs (hebasto)
407- #14193 validation: Add missing mempool locks (MarcoFalke)
408- #15681 Allow one extra single-ancestor transaction per package (TheBlueMatt)
409- #15305 [validation] Crash if disconnecting a block fails (sdaftuar)
410- #16471 log correct messages when CPFP fails (jnewbery)
411- #16433 txmempool: Remove unused default value MemPoolRemovalReason::UNKNOWN (MarcoFalke)
412- #13868 Remove unused fScriptChecks parameter from CheckInputs (Empact)
413- #16421 Conservatively accept RBF bumps bumping one tx at the package limits (TheBlueMatt)
414- #16854 Prevent UpdateTip log message from being broken up (stevenroose)
415- #16956 validation: Make GetWitnessCommitmentIndex public (MarcoFalke)
416- #16713 Ignore old versionbit activations to avoid 'unknown softforks' warning (jnewbery)
417- #17002 chainparams: Bump assumed chain params (MarcoFalke)
418- #16849 Fix block index inconsistency in InvalidateBlock() (sdaftuar)
419
420### P2P protocol and network code
421- #15597 Generate log entry when blocks messages are received unexpectedly (pstratem)
422- #15654 Remove unused unsanitized user agent string CNode::strSubVer (MarcoFalke)
423- #15689 netaddress: Update CNetAddr for ORCHIDv2 (dongcarl)
424- #15834 Fix transaction relay bugs introduced in #14897 and expire transactions from peer in-flight map (sdaftuar)
425- #15651 torcontrol: Use the default/standard network port for Tor hidden services, even if the internal port is set differently (luke-jr)
426- #16188 Document what happens to getdata of unknown type (MarcoFalke)
427- #15649 Add ChaCha20Poly1305@Bitcoin AEAD (jonasschnelli)
428- #16152 Disable bloom filtering by default (TheBlueMatt)
429- #15993 Drop support of the insecure miniUPnPc versions (hebasto)
430- #16197 Use mockable time for tx download (MarcoFalke)
431- #16248 Make whitebind/whitelist permissions more flexible (NicolasDorier)
432- #16618 [Fix] Allow connection of a noban banned peer (NicolasDorier)
433- #16631 Restore default whitelistrelay to true (NicolasDorier)
434- #15759 Add 2 outbound block-relay-only connections (sdaftuar)
435- #15558 Don't query all DNS seeds at once (sipa)
436- #16999 0.19 seeds update (laanwj)
437
438### Wallet
439- #15288 Remove wallet -> node global function calls (ryanofsky)
440- #15491 Improve log output for errors during load (gwillen)
441- #13541 wallet/rpc: sendrawtransaction maxfeerate (kallewoof)
442- #15680 Remove resendwallettransactions RPC method (jnewbery)
443- #15508 Refactor analyzepsbt for use outside RPC code (gwillen)
444- #15747 Remove plethora of Get*Balance (MarcoFalke)
445- #15728 Refactor relay transactions (jnewbery)
446- #15639 bitcoin-wallet tool: Drop libbitcoin_server.a dependency (ryanofsky)
447- #15853 Remove unused import checkpoints.h (MarcoFalke)
448- #15780 add cachable amounts for caching credit/debit values (kallewoof)
449- #15778 Move maxtxfee from node to wallet (jnewbery)
450- #15901 log on rescan completion (andrewtoth)
451- #15917 Avoid logging no_such_file_or_directory error (promag)
452- #15452 Replace CScriptID and CKeyID in CTxDestination with dedicated types (instagibbs)
453- #15870 Only fail rescan when blocks have actually been pruned (MarcoFalke)
454- #15006 Add option to create an encrypted wallet (achow101)
455- #16001 Give WalletModel::UnlockContext move semantics (sipa)
456- #15741 Batch write imported stuff in importmulti (achow101)
457- #16144 do not encrypt wallets with disabled private keys (mrwhythat)
458- #15024 Allow specific private keys to be derived from descriptor (meshcollider)
459- #13756 "avoid_reuse" wallet flag for improved privacy (kallewoof)
460- #16226 Move ismine to the wallet module (achow101)
461- #16239 wallet/rpc: follow-up clean-up/fixes to avoid_reuse (kallewoof)
462- #16286 refactoring: wallet: Fix GCC 7.4.0 warning (hebasto)
463- #16257 abort when attempting to fund a transaction above -maxtxfee (Sjors)
464- #16237 Have the wallet give out destinations instead of keys (achow101)
465- #16322 Fix -maxtxfee check by moving it to CWallet::CreateTransaction (promag)
466- #16361 Remove redundant pre-TopUpKeypool check (instagibbs)
467- #16244 Move wallet creation out of the createwallet rpc into its own function (achow101)
468- #16227 Refactor CWallet's inheritance chain (achow101)
469- #16208 Consume ReserveDestination on successful CreateTransaction (instagibbs)
470- #16301 Use CWallet::Import* functions in all import* RPCs (achow101)
471- #16402 Remove wallet settings from chainparams (MarcoFalke)
472- #16415 Get rid of PendingWalletTx class (ryanofsky)
473- #15588 Log the actual wallet file version and no longer publicly expose the "version" record (achow101)
474- #16399 Improve wallet creation (fjahr)
475- #16475 Enumerate walletdb keys (MarcoFalke)
476- #15709 Do not add "setting" key as unknown (Bushstar)
477- #16451 Remove CMerkleTx (jnewbery)
478- #15906 Move min_depth and max_depth to coin control (amitiuttarwar)
479- #16502 Drop unused OldKey (promag)
480- #16394 Allow createwallet to take empty passwords to make unencrypted wallets (achow101)
481- #15911 Use wallet RBF default for walletcreatefundedpsbt (Sjors)
482- #16503 Remove p2pEnabled from Chain interface (ariard)
483- #16557 restore coinbase and confirmed/conflicted checks in SubmitMemoryPoolAndRelay() (jnewbery)
484- #14934 Descriptor expansion cache clarifications (Sjors)
485- #16383 rpcwallet: default include_watchonly to true for watchonly wallets (jb55)
486- #16542 Return more specific errors about invalid descriptors (achow101)
487- #16572 Fix Char as Bool in Wallet (JeremyRubin)
488- #16753 extract PubKey from P2PK script with Solver (theStack)
489- #16716 Use wallet name instead of pointer on unload/release (promag)
490- #16185 gettransaction: add an argument to decode the transaction (darosior)
491- #16745 Translate all initErrors in CreateWalletFromFile (MarcoFalke)
492- #16792 Assert that the HRP is lowercase in Bech32::Encode (meshcollider)
493- #16624 encapsulate transactions state (ariard)
494- #16830 Cleanup walletinitinterface.h (hebasto)
495- #16796 Fix segfault in CreateWalletFromFile (MarcoFalke)
496- #16866 Rename 'decode' argument in gettransaction method to 'verbose' (jnewbery)
497- #16727 Explicit feerate for bumpfee (instagibbs)
498- #16609 descriptor: fix missed m_script_arg arg renaming in #14934 (fanquake)
499
500### RPC and other APIs