dash/doc/release-notes.md

(note: this is a temporary file, to be added-to by anybody, and moved to release-notes at release time)

Bitcoin Core version version is now available from:

https://bitcoin.org/bin/bitcoin-core-*version*/

This is a new major version release, including new features, various bugfixes and performance improvements, as well as updated translations.

Please report bugs using the issue tracker at github:

https://github.com/bitcoin/bitcoin/issues

To receive security and update notifications, please subscribe to:

https://bitcoincore.org/en/list/announcements/join/

Compatibility

Bitcoin Core is extensively tested on multiple operating systems using the Linux kernel, macOS 10.8+, and Windows Vista and later.

Microsoft ended support for Windows XP on April 8th, 2014. No attempt is made to prevent installing or running the software on Windows XP, you can still do so at your own risk but be aware that there are known instabilities. Please do not report issues about Windows XP to the issue tracker.

Bitcoin Core should also work on most other Unix-like systems but is not frequently tested on them.

Notable changes

Low-level RPC changes

• importprunedfunds only accepts two required arguments. Some versions accept an optional third arg, which was always ignored. Make sure to never pass more than two arguments.

Fee Estimation Changes

• Since 0.13.2 fee estimation for a confirmation target of 1 block has been disabled. This is only a minor behavior change as there was often insufficient data for this target anyway. estimatefee 1 will now always return -1 and estimatesmartfee 1 will start searching at a target of 2.

• The default target for fee estimation is changed to 6 blocks in both the GUI (previously 25) and for RPC calls (previously 2).

Removal of Priority Estimation

• Estimation of "priority" needed for a transaction to be included within a target number of blocks has been removed. The rpc calls are deprecated and will either return -1 or 1e24 appropriately. The format for fee_estimates.dat has also changed to no longer save these priority estimates. It will automatically be converted to the new format which is not readable by prior versions of the software.

• The concept of "priority" (coin age) transactions is planned to be removed in the next major version. To prepare for this, the default for the rate limit of priority transactions (-limitfreerelay) has been set to 0 kB/minute. This is not to be confused with the prioritisetransaction RPC which will remain supported for adding fee deltas to transactions.

P2P connection management

• Peers manually added through the addnode option or addnode RPC now have their own limit of eight connections which does not compete with other inbound or outbound connection usage and is not subject to the maxconnections limitation.

• New connections to manually added peers are much faster.

Introduction of assumed-valid blocks

• A significant portion of the initial block download time is spent verifying scripts/signatures. Although the verification must pass to ensure the security of the system, no other result from this verification is needed: If the node knew the history of a given block were valid it could skip checking scripts for its ancestors.

• A new configuration option 'assumevalid' is provided to express this knowledge to the software. Unlike the 'checkpoints' in the past this setting does not force the use of a particular chain: chains that are consistent with it are processed quicker, but other chains are still accepted if they'd otherwise be chosen as best. Also unlike 'checkpoints' the user can configure which block history is assumed true, this means that even outdated software can sync more quickly if the setting is updated by the user.

• Because the validity of a chain history is a simple objective fact it is much easier to review this setting. As a result the software ships with a default value adjusted to match the current chain shortly before release. The use of this default value can be disabled by setting -assumevalid=0

0.14.0 Change log

Detailed release notes follow. This overview includes changes that affect behavior, not code moves, refactors and string updates. For convenience in locating the code changes and accompanying discussion, both the pull request and git merge commit are mentioned.

RPC and REST

UTXO set query (GET /rest/getutxos/<checkmempool>/<txid>-<n>/<txid>-<n>/.../<txid>-<n>.<bin|hex|json>) responses were changed to return status code HTTP_BAD_REQUEST (400) instead of HTTP_INTERNAL_SERVER_ERROR (500) when requests contain invalid parameters.

The first boolean argument to getaddednodeinfo has been removed. This is an incompatible change.

Call "getmininginfo" loses the "testnet" field in favor of the more generic "chain" (which has been present for years).

Configuration and command-line options

Block and transaction handling

P2P protocol and network code

Validation

Build system

Wallet

0.14.0 Fundrawtransaction change address reuse

Before 0.14, fundrawtransaction was by default wallet stateless. In almost all cases fundrawtransaction does add a change-output to the outputs of the funded transaction. Before 0.14, the used keypool key was never marked as change-address key and directly returned to the keypool (leading to address reuse). Before 0.14, calling getnewaddress directly after fundrawtransaction did generate the same address as the change-output address.

Since 0.14, fundrawtransaction does reserve the change-output-key from the keypool by default (optional by setting reserveChangeKey, default = true)

Users should also consider using getrawchangeaddress() in conjunction with fundrawtransaction's changeAddress option.

GUI

Tests

Miscellaneous

Credits

Thanks to everyone who directly contributed to this release:

As well as everyone that helped translating on Transifex.