path: root/doc/release-notes.md

Bitcoin Core version 0.12.0 is now available from:

  <https://bitcoin.org/bin/bitcoin-core-0.12.0/>

This is a new major version release, bringing new features and other improvements.

Please report bugs using the issue tracker at github:

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

Upgrading and downgrading
=========================

How to Upgrade
--------------

If you are running an older version, shut it down. Wait until it has completely
shut down (which might take a few minutes for older versions), then run the
installer (on Windows) or just copy over /Applications/Bitcoin-Qt (on Mac) or
bitcoind/bitcoin-qt (on Linux).

Downgrade warning
------------------

### Downgrade to a version < 0.10.0

Because release 0.10.0 and later makes use of headers-first synchronization and
parallel block download (see further), the block files and databases are not
backwards-compatible with pre-0.10 versions of Bitcoin Core or other software:

* Blocks will be stored on disk out of order (in the order they are
received, really), which makes it incompatible with some tools or
other programs. Reindexing using earlier versions will also not work
anymore as a result of this.

* The block index database will now hold headers for which no block is
stored on disk, which earlier versions won't support.

If you want to be able to downgrade smoothly, make a backup of your entire data
directory. Without this your node will need start syncing (or importing from
bootstrap.dat) anew afterwards. It is possible that the data from a completely
synchronised 0.10 node may be usable in older versions as-is, but this is not
supported and may break as soon as the older version attempts to reindex.

This does not affect wallet forward or backward compatibility.

### Downgrade to a version < 0.12.0

Because release 0.12.0 and later will obfuscate the chainstate on every
fresh sync or reindex, the chainstate is not backwards-compatible with
pre-0.12 versions of Bitcoin Core or other software.

If you want to downgrade after you have done a reindex with 0.12.0 or later,
you will need to reindex when you first start Bitcoin Core version 0.11 or
earlier.

Notable changes
===============

Signature validation using libsecp256k1
---------------------------------------

ECDSA signatures inside Bitcoin transactions now use validation using
[https://github.com/bitcoin/secp256k1](libsecp256k1) instead of OpenSSL.

Depending on the platform, this means a significant speedup for raw signature
validation speed. The advantage is largest on x86_64, where validation is over
five times faster. In practice, this translates to a raw reindexing and new
block validation times that are less than half of what it was before.

Libsecp256k1 has undergone very extensive testing and validation.

A side effect of this change is that libconsensus no longer depends on OpenSSL.

Reduce upload traffic
---------------------

A major part of the outbound traffic is caused by serving historic blocks to
other nodes in initial block download state.

It is now possible to reduce the total upload traffic via the `-maxuploadtarget`
parameter. This is *not* a hard limit but a threshold to minimize the outbound
traffic. When the limit is about to be reached, the uploaded data is cut by not
serving historic blocks (blocks older than one week).
Moreover, any SPV peer is disconnected when they request a filtered block.

This option can be specified in MiB per day and is turned off by default
(`-maxuploadtarget=0`).
The recommended minimum is 144 * MAX_BLOCK_SIZE (currently 144MB) per day.

Whitelisted peers will never be disconnected, although their traffic counts for
calculating the target.

A more detailed documentation about keeping traffic low can be found in
[/doc/reduce-traffic.md](/doc/reduce-traffic.md).

Direct headers announcement (BIP 130)
-------------------------------------

Between compatible peers, [BIP 130]
(https://github.com/bitcoin/bips/blob/master/bip-0130.mediawiki)
direct headers announcement is used. This means that blocks are advertized by
announcing their headers directly, instead of just announcing the hash. In a
reorganization, all new headers are sent, instead of just the new tip. This
can often prevent an extra roundtrip before the actual block is downloaded.

With this change, pruning nodes are now able to relay new blocks to compatible
peers.

Memory pool limiting
--------------------

Previous versions of Bitcoin Core had their mempool limited by checking
a transaction's fees against the node's minimum relay fee. There was no
upper bound on the size of the mempool and attackers could send a large
number of transactions paying just slighly more than the default minimum
relay fee to crash nodes with relatively low RAM. A temporary workaround
for previous versions of Bitcoin Core was to raise the default minimum
relay fee.

Bitcoin Core 0.12 will have a strict maximum size on the mempool. The
default value is 300 MB and can be configured with the `-maxmempool`
parameter. Whenever a transaction would cause the mempool to exceed
its maximum size, the transaction that (along with in-mempool descendants) has
the lowest total feerate (as a package) will be evicted and the node's effective
minimum relay feerate will be increased to match this feerate plus the initial
minimum relay feerate. The initial minimum relay feerate is set to
1000 satoshis per kB.

Bitcoin Core 0.12 also introduces new default policy limits on the length and
size of unconfirmed transaction chains that are allowed in the mempool
(generally limiting the length of unconfirmed chains to 25 transactions, with a
total size of 101 KB).  These limits can be overriden using command line
arguments; see the extended help (`--help -help-debug`) for more information.

Replace-by-fee transactions
---------------------------

It is now possible to replace transactions in the transaction memory pool of
Bitcoin Core 0.12 nodes. Bitcoin Core will only allow replacement of
transactions which have any of their inputs' `nSequence` number set to less
than `0xffffffff - 1`.  Moreover, a replacement transaction may only be
accepted when it pays sufficient fee, as described in [BIP 125]
(https://github.com/bitcoin/bips/blob/master/bip-0125.mediawiki).

Transaction replacement can be disabled with a new command line option,
`-permitrbf=false`.  Transactions signaling replacement under BIP125 will still
be allowed into the mempool in this configuration, but replacements will be
rejected.  This option is intended for miners who want to continue the
transaction selection behavior of previous releases.

The `-permitrbf` option is *not recommended* for wallet users seeking to avoid
receipt of unconfirmed opt-in transactions, because this option does not
prevent transactions which are replaceable under BIP 125 from being accepted
(only subsequent replacements, which other nodes on the network that implement
BIP 125 are likely to relay and mine).  Wallet users wishing to detect whether
a transaction is subject to replacement under BIP 125 should instead use the
updated RPC calls `gettransaction` and `listtransactions`, which now have an
additional field in the output indicating if a transaction is replaceable under
BIP125 ("bip125-replaceable").

Note that the wallet in Bitcoin Core 0.12 does not yet have support for
creating transactions that would be replaceable under BIP 125.


RPC: Random-cookie RPC authentication
---------------------------------------

When no `-rpcpassword` is specified, the daemon now uses a special 'cookie'
file for authentication. This file is generated with random content when the
daemon starts, and deleted when it exits. Its contents are used as
authentication token. Read access to this file controls who can access through
RPC. By default it is stored in the data directory but its location can be
overridden with the option `-rpccookiefile`.

This is similar to Tor's CookieAuthentication: see
https://www.torproject.org/docs/tor-manual.html.en

This allows running bitcoind without having to do any manual configuration.

Relay: Any sequence of pushdatas in OP_RETURN outputs now allowed
-----------------------------------------------------------------

Previously OP_RETURN outputs with a payload were only relayed and mined if they
had a single pushdata. This restriction has been lifted to allow any
combination of data pushes and numeric constant opcodes (OP_1 to OP_16) after
the OP_RETURN. The limit on OP_RETURN output size is now applied to the entire
serialized scriptPubKey, 83 bytes by default. (the previous 80 byte default plus
three bytes overhead)

Relay and Mining: Priority transactions
---------------------------------------

Transactions that do not pay the minimum relay fee, are called "free
transactions" or priority transactions. Previous versions of Bitcoin
Core would relay and mine priority transactions depending on their
setting of `-limitfreerelay=<r>` (default: `r=15` kB per minute) and
`-blockprioritysize=<s>` (default: `50000` bytes of a block's
priority space).

Priority code is scheduled for removal in Bitcoin Core 0.13. In
Bitcoin Core 0.12, the default block priority size has been set to `0`
and the priority calculation has been simplified to only include the
coin age of inputs that were in the blockchain at the time the transaction
was accepted into the mempool.  In addition priority transactions are not
accepted to the mempool if mempool limiting has triggered a higher effective
minimum relay fee.

Automatically use Tor hidden services
-------------------------------------

Starting with Tor version 0.2.7.1 it is possible, through Tor's control socket
API, to create and destroy 'ephemeral' hidden services programmatically.
Bitcoin Core has been updated to make use of this.

This means that if Tor is running (and proper authorization is available),
Bitcoin Core automatically creates a hidden service to listen on, without
manual configuration. Bitcoin Core will also use Tor automatically to connect
to other .onion nodes if the control socket can be successfully opened. This
will positively affect the number of available .onion nodes and their usage.

This new feature is enabled by default if Bitcoin Core is listening, and
a connection to Tor can be made. It can be configured with the `-listenonion`,
`-torcontrol` and `-torpassword` settings. To show verbose debugging
information, pass `-debug=tor`.

Notifications through ZMQ
-------------------------

Bitcoind can now (optionally) asynchronously notify clients through a
ZMQ-based PUB socket of the arrival of new transactions and blocks.
This feature requires installation of the ZMQ C API library 4.x and
configuring its use through the command line or configuration file.
Please see [docs/zmq.md](/doc/zmq.md) for details of operation.

Wallet: Transaction fees
------------------------

Various improvements have been made to how the wallet calculates
transaction fees.

Users can decide to pay a predefined fee rate by setting `-paytxfee=<n>`
(or `settxfee <n>` rpc during runtime). A value of `n=0` signals Bitcoin
Core to use floating fees. By default, Bitcoin Core will use floating
fees.

Based on past transaction data, floating fees approximate the fees
required to get into the `m`th block from now. This is configurable
with `-txconfirmtarget=<m>` (default: `2`).

Sometimes, it is not possible to give good estimates, or an estimate
at all. Therefore, a fallback value can be set with `-fallbackfee=<f>`
(default: `0.0002` BTC/kB).

At all times, Bitcoin Core will cap fees at `-maxtxfee=<x>` (default:
0.10) BTC.
Furthermore, Bitcoin Core will never create transactions smaller than
the current minimum relay fee.
Finally, a user can set the minimum fee rate for all transactions with
`-mintxfee=<i>`, which defaults to 1000 satoshis per kB.

Wallet: Negative confirmations and conflict detection
-----------------------------------------------------

The wallet will now report a negative number for confirmations that indicates
how deep in the block chain the conflict is found. For example, if a transaction
A has 5 confirmations and spends the same input as a wallet transaction B, B
will be reported as having -5 confirmations. If another wallet transaction C
spends an output from B, it will also be reported as having -5 confirmations.
To detect conflicts with historical transactions in the chain a one-time
`-rescan` may be needed.

Unlike earlier versions, unconfirmed but non-conflicting transactions will never
get a negative confirmation count. They are not treated as spendable unless
they're coming from ourself (change) and accepted into our local mempool,
however. The new "trusted" field in the `listtransactions` RPC output
indicates whether outputs of an unconfirmed transaction are considered
spendable.

Wallet: Merkle branches removed
-------------------------------

Previously, every wallet transaction stored a Merkle branch to prove its
presence in blocks. This wasn't being used for more than an expensive
sanity check. Since 0.12, these are no longer stored. When loading a
0.12 wallet into an older version, it will automatically rescan to avoid
failed checks.

Wallet: Pruning
---------------

With 0.12 it is possible to use wallet functionality in pruned mode.
However, rescans as well as the RPCs `importwallet`, `importaddress`,
`importprivkey` are disabled.

To enable block pruning set `prune=<N>` on the command line or in
`bitcoin.conf`, where `N` is the number of MiB to allot for
raw block & undo data.

`NODE_BLOOM` service bit
------------------------

Support for the `NODE_BLOOM` service bit, as described in [BIP
111](https://github.com/bitcoin/bips/blob/master/bip-0111.mediawiki), has been
added to the P2P protocol code.

BIP 111 defines a service bit to allow peers to advertise that they support
bloom filters (such as used by SPV clients) explicitly. It also bumps the protocol
version to allow peers to identify old nodes which allow bloom filtering of the
connection despite lacking the new service bit.

In this version, it is only enforced for peers that send protocol versions
`>=70011`. For the next major version it is planned that this restriction will be
removed. It is recommended to update SPV clients to check for the `NODE_BLOOM`
service bit for nodes that report versions newer than 70011.

Option parsing behavior
-----------------------

Command line options are now parsed strictly in the order in which they are
specified. It used to be the case that `-X -noX` ends up, unintuitively, with X
set, as `-X` had precedence over `-noX`. This is no longer the case. Like for
other software, the last specified value for an option will hold.

RPC: Low-level API changes
--------------------------

- Monetary amounts can be provided as strings. This means that for example the
  argument to sendtoaddress can be "0.0001" instead of 0.0001. This can be an
  advantage if a JSON library insists on using a lossy floating point type for
  numbers, which would be dangerous for monetary amounts.

* The `asm` property of each scriptSig now contains the decoded signature hash
  type for each signature that provides a valid defined hash type.

* OP_NOP2 has been renamed to OP_CHECKLOCKTIMEVERIFY by [BIP 65](https://github.com/bitcoin/bips/blob/master/bip-0065.mediawiki)

The following items contain assembly representations of scriptSig signatures
and are affected by this change:

- RPC `getrawtransaction`
- RPC `decoderawtransaction`
- RPC `decodescript`
- REST `/rest/tx/` (JSON format)
- REST `/rest/block/` (JSON format when including extended tx details)
- `bitcoin-tx -json`

For example, the `scriptSig.asm` property of a transaction input that
previously showed an assembly representation of:

    304502207fa7a6d1e0ee81132a269ad84e68d695483745cde8b541e3bf630749894e342a022100c1f7ab20e13e22fb95281a870f3dcf38d782e53023ee313d741ad0cfbc0c509001 400000 OP_NOP2

now shows as:

    304502207fa7a6d1e0ee81132a269ad84e68d695483745cde8b541e3bf630749894e342a022100c1f7ab20e13e22fb95281a870f3dcf38d782e53023ee313d741ad0cfbc0c5090[ALL] 400000 OP_CHECKLOCKTIMEVERIFY

Note that the output of the RPC `decodescript` did not change because it is
configured specifically to process scriptPubKey and not scriptSig scripts.

RPC: SSL support dropped
----------------------------

SSL support for RPC, previously enabled by the option `rpcssl` has been dropped
from both the client and the server. This was done in preparation for removing
the dependency on OpenSSL for the daemon completely.

Trying to use `rpcssl` will result in an error:

    Error: SSL mode for RPC (-rpcssl) is no longer supported.

If you are one of the few people that relies on this feature, a flexible
migration path is to use `stunnel`. This is an utility that can tunnel
arbitrary TCP connections inside SSL. On e.g. Ubuntu it can be installed with:

    sudo apt-get install stunnel4

Then, to tunnel a SSL connection on 28332 to a RPC server bound on localhost on port 18332 do:

    stunnel -d 28332 -r 127.0.0.1:18332 -p stunnel.pem -P ''

It can also be set up system-wide in inetd style.

Another way to re-attain SSL would be to setup a httpd reverse proxy. This solution
would allow the use of different authentication, loadbalancing, on-the-fly compression and
caching. A sample config for apache2 could look like:

    Listen 443

    NameVirtualHost *:443
    <VirtualHost *:443>

    SSLEngine On
    SSLCertificateFile /etc/apache2/ssl/server.crt
    SSLCertificateKeyFile /etc/apache2/ssl/server.key

    <Location /bitcoinrpc>
        ProxyPass http://127.0.0.1:8332/
        ProxyPassReverse http://127.0.0.1:8332/
        # optional enable digest auth
        # AuthType Digest
        # ...

        # optional bypass bitcoind rpc basic auth
        # RequestHeader set Authorization "Basic <hash>"
        # get the <hash> from the shell with: base64 <<< bitcoinrpc:<password>
    </Location>

    # Or, balance the load:
    # ProxyPass / balancer://balancer_cluster_name

    </VirtualHost>

Mining Code Changes
-------------------

The mining code in 0.12 has been optimized to be significantly faster and use less
memory. As part of these changes, consensus critical calculations are cached on a
transaction's acceptance into the mempool and the mining code now relies on the
consistency of the mempool to assemble blocks. However all blocks are still tested
for validity after assembly.

Other P2P Changes
-----------------

The list of banned peers is now stored on disk rather than in memory.
Restarting bitcoind will no longer clear out the list of banned peers; instead
a new RPC call (`clearbanned`) can be used to manually clear the list.  The new
`setban` RPC call can also be used to manually ban or unban a peer.

0.12.0 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

- #6121 `466f0ea` Convert entire source tree from json_spirit to UniValue
- #6234 `d38cd47` fix rpcmining/getblocktemplate univalue transition logic error
- #6239 `643114f` Don't go through double in AmountFromValue and ValueFromAmount
- #6266 `ebab5d3` Fix univalue handling of \u0000 characters.
- #6276 `f3d4dbb` Fix getbalance * 0
- #6257 `5ebe7db` Add `paytxfee` and `errors` JSON fields where appropriate
- #6271 `754aae5` New RPC command disconnectnode
- #6158 `0abfa8a` Add setban/listbanned RPC commands
- #6307 `7ecdcd9` rpcban fixes
- #6290 `5753988` rpc: make `gettxoutsettinfo` run lock-free
- #6262 `247b914` Return all available information via RPC call "validateaddress"
- #6339 `c3f0490` UniValue: don't escape solidus, keep espacing of reverse solidus
- #6353 `6bcb0a2` Show softfork status in getblockchaininfo
- #6247 `726e286` Add getblockheader RPC call
- #6362 `d6db115` Fix null id in RPC response during startup
- #5486 `943b322` [REST] JSON support for /rest/headers
- #6379 `c52e8b3` rpc: Accept scientific notation for monetary amounts in JSON
- #6388 `fd5dfda` rpc: Implement random-cookie based authentication
- #6457 `3c923e8` Include pruned state in chaininfo.json
- #6456 `bfd807f` rpc: Avoid unnecessary parsing roundtrip in number formatting, fix locale issue
- #6380 `240b30e` rpc: Accept strings in AmountFromValue
- #6346 `6bb2805` Add OP_RETURN support in createrawtransaction RPC call, add tests.
- #6013 `6feeec1` [REST] Add memory pool API
- #6576 `da9beb2` Stop parsing JSON after first finished construct.
- #5677 `9aa9099` libevent-based http server
- #6633 `bbc2b39` Report minimum ping time in getpeerinfo
- #6648 `cd381d7` Simplify logic of REST request suffix parsing.
- #6695 `5e21388` libevent http fixes
- #5264 `48efbdb` show scriptSig signature hash types in transaction decodes. fixes #3166
- #6719 `1a9f19a` Make HTTP server shutdown more graceful
- #6859 `0fbfc51` http: Restrict maximum size of http + headers
- #5936 `bf7c195` [RPC] Add optional locktime to createrawtransaction
- #6877 `26f5b34` rpc: Add maxmempool and effective min fee to getmempoolinfo
- #6970 `92701b3` Fix crash in validateaddress with -disablewallet
- #5574 `755b4ba` Expose GUI labels in RPC as comments
- #6990 `dbd2c13` http: speed up shutdown
- #7013 `36baa9f` Remove LOCK(cs_main) from decodescript
- #6999 `972bf9c` add (max)uploadtarget infos to getnettotals RPC help
- #7011 `31de241` Add mediantime to getblockchaininfo
- #7065 `f91e29f` http: add Boost 1.49 compatibility
- #7087 `be281d8` [Net]Add -enforcenodebloom option
- #7044 `438ee59` RPC: Added additional config option for multiple RPC users.
- #7072 `c143c49` [RPC] Add transaction size to JSON output
- #7022 `9afbd96` Change default block priority size to 0
- #7141 `c0c08c7` rpc: Don't translate warning messages
- #7312 `fd4bd50` Add RPC call abandontransaction
- #7222 `e25b158` RPC: indicate which transactions are replaceable

### Configuration and command-line options

- #6164 `8d05ec7` Allow user to use -debug=1 to enable all debugging
- #5288 `4452205` Added -whiteconnections=<n> option
- #6284 `10ac38e` Fix argument parsing oddity with -noX
- #6489 `c9c017a` Give a better error message if system clock is bad
- #6462 `c384800` implement uacomment config parameter which can add comments to user agent as per BIP-0014
- #6647 `a3babc8` Sanitize uacomment
- #6742 `3b2d37c` Changed logging to make -logtimestamps to work also for -printtoconsole #6742
- #6846 `2cd020d` alias -h for -help
- #6622 `7939164` Introduce -maxuploadtarget
- #6881 `2b62551` Debug: Add option for microsecond precision in debug.log
- #6776 `e06c14f` Support -checkmempool=N, which runs checks once every N transactions
- #6896 `d482c0a` Make -checkmempool=1 not fail through int32 overflow
- #6993 `b632145` Add -blocksonly option
- #7323 `a344880` 0.12: Backport -bytespersigop option
- #7386 `da83ecd` Add option `-permitrbf` to set transaction replacement policy
- #7290 `b16b5bc` Add missing options help

### Block and transaction handling

- #6203 `f00b623` Remove P2SH coinbase flag, no longer interesting
- #6222 `9c93ee5` Explicitly set tx.nVersion for the genesis block and mining tests
- #5985 `3a1d3e8` Fix removing of orphan transactions
- #6221 `dd8fe82` Prune: Support noncontiguous block files
- #6124 `41076aa` Mempool only CHECKLOCKTIMEVERIFY (BIP65) verification, unparameterized version
- #6329 `d0a10c1` acceptnonstdtxn option to skip (most) "non-standard transaction" checks, for testnet/regtest only
- #6410 `7cdefb9` Implement accurate memory accounting for mempool
- #6444 `24ce77d` Exempt unspendable transaction outputs from dust checks
- #5913 `a0625b8` Add absurdly high fee message to validation state
- #6177 `2f746c6` Prevent block.nTime from decreasing
- #6377 `e545371` Handle no chain tip available in InvalidChainFound()
- #6551 `39ddaeb` Handle leveldb::DestroyDB() errors on wipe failure
- #6654 `b0ce450` Mempool package tracking
- #6715 `82d2aef` Fix mempool packages
- #6680 `4f44530` use CBlockIndex instead of uint256 for UpdatedBlockTip signal
- #6650 `4fac576` Obfuscate chainstate
- #6777 `9caaf6e` Unobfuscate chainstate data in CCoinsViewDB::GetStats
- #6722 `3b20e23` Limit mempool by throwing away the cheapest txn and setting min relay fee to it
- #6889 `38369dd` fix locking issue with new mempool limiting
- #6464 `8f3b3cd` Always clean up manual transaction prioritization
- #6865 `d0badb9` Fix chainstate serialized_size computation
- #6566 `ff057f4` BIP-113: Mempool-only median time-past as endpoint for lock-time calculations
- #6934 `3038eb6` Restores mempool only BIP113 enforcement
- #6965 `de7d459` Benchmark sanity checks and fork checks in ConnectBlock
- #6918 `eb6172a` Make sigcache faster, more efficient, larger
- #6771 `38ed190` Policy: Lower default limits for tx chains
- #6932 `73fa5e6` ModifyNewCoins saves database lookups
- #5967 `05d5918` Alter assumptions in CCoinsViewCache::BatchWrite
- #6871 `0e93586` nSequence-based Full-RBF opt-in
- #7008 `eb77416` Lower bound priority
- #6915 `2ef5ffa` [Mempool] Improve removal of invalid transactions after reorgs
- #6898 `4077ad2` Rewrite CreateNewBlock
- #6872 `bdda4d5` Remove UTXO cache entries when the tx they were added for is removed/does not enter mempool
- #7062 `12c469b` [Mempool] Fix mempool limiting and replace-by-fee for PrioritiseTransaction
- #7276 `76de36f` Report non-mandatory script failures correctly
- #7217 `e08b7cb` Mark blocks with too many sigops as failed
- #7387 `f4b2ce8` Get rid of inaccurate ScriptSigArgsExpected

### P2P protocol and network code

- #6172 `88a7ead` Ignore getheaders requests when not synced
- #5875 `9d60602` Be stricter in processing unrequested blocks
- #6256 `8ccc07c` Use best header chain timestamps to detect partitioning
- #6283 `a903ad7` make CAddrMan::size() return the correct type of size_t
- #6272 `40400d5` Improve proxy initialization (continues #4871)
- #6310 `66e5465` banlist.dat: store banlist on disk
- #6412 `1a2de32` Test whether created sockets are select()able
- #6498 `219b916` Keep track of recently rejected transactions with a rolling bloom filter (cont'd)
- #6556 `70ec975` Fix masking of irrelevant bits in address groups.
- #6530 `ea19c2b` Improve addrman Select() performance when buckets are nearly empty
- #6583 `af9305a` add support for miniupnpc api version 14
- #6374 `69dc5b5` Connection slot exhaustion DoS mitigation
- #6636 `536207f` net: correctly initialize nMinPingUsecTime
- #6579 `0c27795` Add NODE_BLOOM service bit and bump protocol version
- #6148 `999c8be` Relay blocks when pruning
- #6588 `cf9bb11` In (strCommand == "tx"), return if AlreadyHave()
- #6974 `2f71b07` Always allow getheaders from whitelisted peers
- #6639 `bd629d7` net: Automatically create hidden service, listen on Tor
- #6984 `9ffc687` don't enforce maxuploadtarget's disconnect for whitelisted peers
- #7046 `c322652` Net: Improve blocks only mode.
- #7090 `d6454f6` Connect to Tor hidden services by default (when listening on Tor)
- #7106 `c894fbb` Fix and improve relay from whitelisted peers
- #7129 `5d5ef3a` Direct headers announcement (rebase of #6494)
- #7079 `1b5118b` Prevent peer flooding inv request queue (redux) (redux)
- #7166 `6ba25d2` Disconnect on mempool requests from peers when over the upload limit.
- #7133 `f31955d` Replace setInventoryKnown with a rolling bloom filter (rebase of #7100)
- #7174 `82aff88` Don't do mempool lookups for "mempool" command without a filter
- #7179 `44fef99` net: Fix sent reject messages for blocks and transactions
- #7181 `8fc174a` net: Add and document network messages in protocol.h
- #7125 `10b88be` Replace global trickle node with random delays

### Validation

- #5927 `8d9f0a6` Reduce checkpoints' effect on consensus.
- #6299 `24f2489` Bugfix: Don't check the genesis block header before accepting it
- #6361 `d7ada03` Use real number of cores for default -par, ignore virtual cores
- #6519 `87f37e2` Make logging for validation optional
- #6351 `2a1090d` CHECKLOCKTIMEVERIFY (BIP65) IsSuperMajority() soft-fork
- #6931 `54e8bfe` Skip BIP 30 verification where not necessary
- #6954 `e54ebbf` Switch to libsecp256k1-based ECDSA validation
- #6508 `61457c2` Switch to a constant-space Merkle root/branch algorithm.
- #6914 `327291a` Add pre-allocated vector type and use it for CScript

### Build system

- #6210 `0e4f2a0` build: disable optional use of gmp in internal secp256k1 build
- #6214 `87406aa` [OSX] revert renaming of Bitcoin-Qt.app and use CFBundleDisplayName (partial revert of #6116)
- #6218 `9d67b10` build/gitian misc updates
- #6269 `d4565b6` gitian: Use the new bitcoin-detached-sigs git repo for OSX signatures
- #6418 `d4a910c` Add autogen.sh to source tarball.
- #6373 `1ae3196` depends: non-qt bumps for 0.12
- #6434 `059b352` Preserve user-passed CXXFLAGS with --enable-debug
- #6501 `fee6554` Misc build fixes
- #6600 `ef4945f` Include bitcoin-tx binary on Debian/Ubuntu
- #6619 `4862708` depends: bump miniupnpc and ccache
- #6801 `ae69a75` [depends] Latest config.guess and config.sub
- #6938 `193f7b5` build: If both Qt4 and Qt5 are installed, use Qt5
- #7092 `348b281` build: Set osx permissions in the dmg to make Gatekeeper happy
- #6980 `eccd671` [Depends] Bump Boost, miniupnpc, ccache & zeromq

### Wallet

- #6183 `87550ee` Fix off-by-one error w/ nLockTime in the wallet
- #6057 `ac5476e` re-enable wallet in autoprune
- #6356 `9e6c33b` Delay initial pruning until after wallet init
- #6088 `91389e5` fundrawtransaction
- #6415 `ddd8d80` Implement watchonly support in fundrawtransaction
- #6567 `0f0f323` Fix crash when mining with empty keypool.
- #6688 `4939eab` Fix locking in GetTransaction.
- #6645 `4dbd43e` Enable wallet key imports without rescan in pruned mode.
- #6550 `5b77244` Do not store Merkle branches in the wallet.
- #5924 `12a7712` Clean up change computation in CreateTransaction.
- #6906 `48b5b84` Reject invalid pubkeys when reading ckey items from the wallet.
- #7010 `e0a5ef8` Fix fundrawtransaction handling of includeWatching
- #6851 `616d61b` Optimisation: Store transaction list order in memory rather than compute it every need
- #6134 `e92377f` Improve usage of fee estimation code
- #7103 `a775182` [wallet, rpc tests] Fix settxfee, paytxfee
- #7105 `30c2d8c` Keep track of explicit wallet conflicts instead of using mempool
- #7096 `9490bd7` [Wallet] Improve minimum absolute fee GUI options
- #6216 `83f06ca` Take the training wheels off anti-fee-sniping
- #4906 `96e8d12` Issue#1643: Coinselection prunes extraneous inputs from ApproximateBestSubset
- #7200 `06c6a58` Checks for null data transaction before issuing error to debug.log
- #7296 `a36d79b` Add sane fallback for fee estimation
- #7293 `ff9b610` Add regression test for vValue sort order 
- #7306 `4707797` Make sure conflicted wallet tx's update balances
- #7381 `621bbd8` [walletdb] Fix syntax error in key parser

### GUI

- #6217 `c57e12a` disconnect peers from peers tab via context menu
- #6209 `ab0ec67` extend rpc console peers tab
- #6484 `1369d69` use CHashWriter also in SignVerifyMessageDialog
- #6487 `9848d42` Introduce PlatformStyle
- #6505 `100c9d3` cleanup icons
- #4587 `0c465f5` allow users to set -onion via GUI
- #6529 `c0f66ce` show client user agent in debug window
- #6594 `878ea69` Disallow duplicate windows.
- #5665 `6f55cdd` add verifySize() function to PaymentServer
- #6317 `ca5e2a1` minor optimisations in peertablemodel
- #6315 `e59d2a8` allow banning and unbanning over UI->peers table
- #6653 `e04b2fa` Pop debug window in foreground when opened twice
- #6864 `c702521` Use monospace font
- #6887 `3694b74` Update coin control and smartfee labels
- #7000 `814697c` add shortcurts for debug-/console-window
- #6951 `03403d8` Use maxTxFee instead of 10000000
- #7051 `a190777` ui: Add "Copy raw transaction data" to transaction list context menu
- #6979 `776848a` simple mempool info in debug window
- #7006 `26af1ac` add startup option to reset Qt settings
- #6780 `2a94cd6` Call init's parameter interaction before we create the UI options model
- #7112 `96b8025` reduce cs_main locks during tip update, more fluently update UI
- #7206 `f43c2f9` Add "NODE_BLOOM" to guiutil so that peers don't get UNKNOWN[4]
- #7282 `5cadf3e` fix coincontrol update issue when deleting a send coins entry
- #7319 `1320300` Intro: Display required space
- #7318 `9265e89` quickfix for RPC timer interface problem
- #7327 `b16b5bc` [Wallet] Transaction View: LastMonth calculation fixed
- #7364 `7726c48` [qt] Windows: Make rpcconsole monospace font larger

### Tests and QA

- #6305 `9005c91` build: comparison tool swap
- #6318 `e307e13` build: comparison tool NPE fix
- #6337 `0564c5b` Testing infrastructure: mocktime fixes
- #6350 `60abba1` add unit tests for the decodescript rpc
- #5881 `3203a08` Fix and improve txn_doublespend.py test
- #6390 `6a73d66` tests: Fix bitcoin-tx signing test case
- #6368 `7fc25c2` CLTV: Add more tests to improve coverage
- #6414 `5121c68` Fix intermittent test failure, reduce test time
- #6417 `44fa82d` [QA] fix possible reorg issue in (fund)rawtransaction(s).py RPC test
- #6398 `3d9362d` rpc: Remove chain-specific RequireRPCPassword
- #6428 `bb59e78` tests: Remove old sh-based test framework
- #5515 `d946e9a` RFC: Assert on probable deadlocks if the second lock isnt try_lock
- #6287 `d2464df` Clang lock debug
- #6465 `410fd74` Don't share objects between TestInstances
- #6534 `6c1c7fd` Fix test locking issues and un-revert the probable-deadlines assertions commit
- #6509 `bb4faee` Fix race condition on test node shutdown
- #6523 `561f8af` Add p2p-fullblocktest.py
- #6590 `981fd92` Fix stale socket rebinding and re-enable python tests for Windows
- #6730 `cb4d6d0` build: Remove dependency of bitcoin-cli on secp256k1
- #6616 `5ab5dca` Regression Tests: Migrated rpc-tests.sh to all Python rpc-tests.py
- #6720 `d479311` Creates unittests for addrman, makes addrman more testable.
- #6853 `c834f56` Added fPowNoRetargeting field to Consensus::Params
- #6827 `87e5539` [rpc-tests] Check return code
- #6848 `f2c869a` Add DERSIG transaction test cases
- #6813 `5242bb3` Support gathering code coverage data for RPC tests with lcov
- #6888 `c8322ff` Clear strMiscWarning before running PartitionAlert
- #6894 `2675276` [Tests] Fix BIP65 p2p test
- #6863 `725539e` [Test Suite] Fix test for null tx input
- #6926 `a6d0d62` tests: Initialize networking on windows
- #6822 `9fa54a1` [tests] Be more strict checking dust
- #6804 `5fcc14e` [tests] Add basic coverage reporting for RPC tests
- #7045 `72dccfc` Bugfix: Use unique autostart filenames on Linux for testnet/regtest
- #7095 `d8368a0` Replace scriptnum_test's normative ScriptNum implementation
- #7063 `6abf6eb` [Tests] Add prioritisetransaction RPC test
- #7137 `16f4a6e` Tests: Explicitly set chain limits in replace-by-fee test
- #7216 `9572e49` Removed offline testnet DNSSeed 'alexykot.me'.
- #7209 `f3ad812` test: don't override BITCOIND and BITCOINCLI if they're set
- #7226 `301f16a` Tests: Add more tests to p2p-fullblocktest
- #7153 `9ef7c54` [Tests] Add mempool_limit.py test
- #7170 `453c567` tests: Disable Tor interaction
- #7229 `1ed938b` [qa] wallet: Check if maintenance changes the balance
- #7308 `d513405` [Tests] Eliminate intermittent failures in sendheaders.py

### Miscellaneous

- #6213 `e54ff2f` [init] add -blockversion help and extend -upnp help
- #5975 `1fea667` Consensus: Decouple ContextualCheckBlockHeader from checkpoints
- #6061 `eba2f06` Separate Consensus::CheckTxInputs and GetSpendHeight in CheckInputs
- #5994 `786ed11` detach wallet from miner
- #6387 `11576a5` [bitcoin-cli] improve error output
- #6401 `6db53b4` Add BITCOIND_SIGTERM_TIMEOUT to OpenRC init scripts
- #6430 `b01981e` doc: add documentation for shared library libbitcoinconsensus
- #6372 `dcc495e` Update Linearize tool to support Windows paths; fix variable scope; update README and example configuration
- #6453 `8fe5cce` Separate core memory usage computation in core_memusage.h
- #6149 `633fe10` Buffer log messages and explicitly open logs
- #6488 `7cbed7f` Avoid leaking file descriptors in RegisterLoad
- #6497 `a2bf40d` Make sure LogPrintf strings are line-terminated
- #6504 `b6fee6b` Rationalize currency unit to "BTC"
- #6507 `9bb4dd8` Removed contrib/bitrpc
- #6527 `41d650f` Use unique name for AlertNotify tempfile
- #6561 `e08a7d9` limitedmap fixes and tests
- #6565 `a6f2aff` Make sure we re-acquire lock if a task throws
- #6599 `f4d88c4` Make sure LogPrint strings are line-terminated
- #6630 `195942d` Replace boost::reverse_lock with our own
- #6103 `13b8282` Add ZeroMQ notifications
- #6692 `d5d1d2e` devtools: don't push if signing fails in github-merge
- #6728 `2b0567b` timedata: Prevent warning overkill
- #6713 `f6ce59c` SanitizeString: Allow hypen char
- #5987 `4899a04` Bugfix: Fix testnet-in-a-box use case
- #6733 `b7d78fd` Simple benchmarking framework
- #6854 `a092970` devtools: Add security-check.py
- #6790 `fa1d252` devtools: add clang-format.py
- #7114 `f3d0fdd` util: Don't set strMiscWarning on every exception
- #7078 `93e0514` uint256::GetCheapHash bigendian compatibility
- #7094 `34e02e0` Assert now > 0 in GetTime GetTimeMillis GetTimeMicros

Credits
=======

Thanks to everyone who directly contributed to this release:

- accraze
- Adam Weiss
- Alex Morcos
- Alex van der Peet
- AlSzacrel
- Altoidnerd
- Andriy Voskoboinyk
- antonio-fr
- Arne Brutschy
- Ashley Holman
- Bob McElrath
- Braydon Fuller
- BtcDrak
- Casey Rodarmor
- centaur1
- Chris Kleeschulte
- Christian Decker
- Cory Fields
- daniel
- Daniel Cousens
- Daniel Kraft
- David Hill
- dexX7
- Diego Viola
- Elias Rohrer
- Eric Lombrozo
- Erik Mossberg
- Esteban Ordano
- EthanHeilman
- fanquake
- Florian Schmaus
- Forrest Voight
- Gavin Andresen
- Gregory Maxwell
- Gregory Sanders
- Ian T
- Irving Ruan
- Jacob Welsh
- James O'Beirne
- Jeff Garzik
- Johnathan Corgan
- Jonas Schnelli
- Jonathan Cross
- João Barbosa
- Jorge Timón
- Josh Lehan
- J Ross Nicoll
- kazcw
- Kevin Cooper
- lpescher
- Luke Dashjr
- Marco
- MarcoFalke
- Mark Friedenbach
- Matt Bogosian
- Matt Corallo
- Matt Quinn
- Micha
- Michael
- Michael Ford
- Midnight Magic
- Mitchell Cash
- mruddy
- Nick
- Patick Strateman
- Patrick Strateman
- Paul Georgiou
- Paul Rabahy
- paveljanik
- Pavel Janík
- Pavel Vasin
- Pavol Rusnak
- Peter Josling
- Peter Todd
- Philip Kaufmann
- Pieter Wuille
- ptschip
- randy-waterhouse
- rion
- Ross Nicoll
- Ryan Havar
- Shaul Kfir
- Simon Males
- Stephen
- Suhas Daftuar
- tailsjoin
- ฿tcDrak
- Thomas Kerin
- Tom Harding
- tulip
- unsystemizer
- Veres Lajos
- Wladimir J. van der Laan
- Zak Wilcox
- zathras-crypto

As well as everyone that helped translating on [Transifex](https://www.transifex.com/projects/p/bitcoin/).