Bitcoin Forum

Bitcoin Core version 0.12.0 is now available from:

  https://bitcoin.org/bin/bitcoin-core-0.12.0/ (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 (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 (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](https://github.com/bitcoin/bitcoin/tree/v0.12.0/doc/reduce-traffic.md (https://github.com/bitcoin/bitcoin/tree/v0.12.0/doc/reduce-traffic.md)).

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

Between compatible peers, [BIP 130]
(https://github.com/bitcoin/bips/blob/master/bip-0130.mediawiki (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.

Opt-in 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 (https://github.com/bitcoin/bips/blob/master/bip-0125.mediawiki)).

Transaction replacement can be disabled with a new command line option,
`-mempoolreplacement=0`.  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 `-mempoolreplacement` 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 (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
---------------------------------------

Bitcoin Core has a heuristic 'priority' based on coin value and age. This
calculation is used for relaying of transactions which do not pay the
minimum relay fee, and can be used as an alternative way of sorting
transactions for mined blocks. Bitcoin Core will relay transactions with
insufficient fees depending on the setting of `-limitfreerelay=<r>` (default:
`r=15` kB per minute) and `-blockprioritysize=<s>`.

In Bitcoin Core 0.12, when mempool limit has been reached a higher minimum
relay fee takes effect to limit memory usage. Transactions which do not meet
this higher effective minimum relay fee will not be relayed or mined even if
they rank highly according to the priority heuristic.

The mining of transactions based on their priority is also now disabled by
default. To re-enable it, simply set `-blockprioritysize=<n>` where is the size
in bytes of your blocks to reserve for these transactions. The old default was
50k, so to retain approximately the same policy, you would set
`-blockprioritysize=50000`.

Additionally, as a result of computational simplifications, the priority value
used for transactions received with unconfirmed inputs is lower than in prior
versions due to avoiding recomputing the amounts as input transactions confirm.

External miner policy set via the `prioritisetransaction` RPC to rank
transactions already in the mempool continues to work as it has previously.
Note, however, that if mining priority transactions is left disabled, the
priority delta will be ignored and only the fee metric will be effective.

This internal automatic prioritization handling is being considered for removal
entirely in Bitcoin Core 0.13, and it is at this time undecided whether the
more accurate priority calculation for chained unconfirmed transactions will be
restored. Community direction on this topic is particularly requested to help
set project priorities.

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](https://github.com/bitcoin/bitcoin/tree/v0.12.0/doc/zmq.md (https://github.com/bitcoin/bitcoin/tree/v0.12.0/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.
This can reduce the disk usage from currently around 60 GB to
around 2 GB.

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.

A value of 0 disables pruning. The minimal value above 0 is 550. Your
wallet is as secure with high values as it is with low ones. Higher
values merely ensure that your node will not shut down upon blockchain
reorganizations of more than 2 days - which are unlikely to happen in
practice. In future releases, a higher value may also help the network
as a whole: stored blocks could be served to other nodes.

For further information about pruning, you may also consult the [release
notes of v0.11.0](https://github.com/bitcoin/bitcoin/blob/v0.11.0/doc/release-notes.md#block-file-pruning (https://github.com/bitcoin/bitcoin/blob/v0.11.0/doc/release-notes.md#block-file-pruning)).

`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 (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 (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:

    304502207fa7a6d1e0ee81132a269ad84e68d695483745cde8b541e3bf630749894e342a022100c 1f7ab20e13e22fb95281a870f3dcf38d782e53023ee313d741ad0cfbc0c509001 400000 OP_NOP2

now shows as:

    304502207fa7a6d1e0ee81132a269ad84e68d695483745cde8b541e3bf630749894e342a022100c 1f7ab20e13e22fb95281a870f3dcf38d782e53023ee313d741ad0cfbc0c5090[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 (Jonas Schnelli)
- #6234 `d38cd47` fix rpcmining/getblocktemplate univalue transition logic error (Jonas Schnelli)
- #6239 `643114f` Don't go through double in AmountFromValue and ValueFromAmount (Wladimir J. van der Laan)
- #6266 `ebab5d3` Fix univalue handling of \u0000 characters. (Daniel Kraft)
- #6276 `f3d4dbb` Fix getbalance * 0 (Tom Harding)
- #6257 `5ebe7db` Add `paytxfee` and `errors` JSON fields where appropriate (Stephen)
- #6271 `754aae5` New RPC command disconnectnode (Alex van der Peet)
- #6158 `0abfa8a` Add setban/listbanned RPC commands (Jonas Schnelli)
- #6307 `7ecdcd9` rpcban fixes (Jonas Schnelli)
- #6290 `5753988` rpc: make `gettxoutsettinfo` run lock-free (Wladimir J. van der Laan)
- #6262 `247b914` Return all available information via RPC call "validateaddress" (dexX7)
- #6339 `c3f0490` UniValue: don't escape solidus, keep espacing of reverse solidus (Jonas Schnelli)
- #6353 `6bcb0a2` Show softfork status in getblockchaininfo (Wladimir J. van der Laan)
- #6247 `726e286` Add getblockheader RPC call (Peter Todd)
- #6362 `d6db115` Fix null id in RPC response during startup (Forrest Voight)
- #5486 `943b322` [REST] JSON support for /rest/headers (Jonas Schnelli)
- #6379 `c52e8b3` rpc: Accept scientific notation for monetary amounts in JSON (Wladimir J. van der Laan)
- #6388 `fd5dfda` rpc: Implement random-cookie based authentication (Wladimir J. van der Laan)
- #6457 `3c923e8` Include pruned state in chaininfo.json (Simon Males)
- #6456 `bfd807f` rpc: Avoid unnecessary parsing roundtrip in number formatting, fix locale issue (Wladimir J. van der Laan)
- #6380 `240b30e` rpc: Accept strings in AmountFromValue (Wladimir J. van der Laan)
- #6346 `6bb2805` Add OP_RETURN support in createrawtransaction RPC call, add tests. (paveljanik)
- #6013 `6feeec1` [REST] Add memory pool API (paveljanik)
- #6576 `da9beb2` Stop parsing JSON after first finished construct. (Daniel Kraft)
- #5677 `9aa9099` libevent-based http server (Wladimir J. van der Laan)
- #6633 `bbc2b39` Report minimum ping time in getpeerinfo (Matt Corallo)
- #6648 `cd381d7` Simplify logic of REST request suffix parsing. (Daniel Kraft)
- #6695 `5e21388` libevent http fixes (Wladimir J. van der Laan)
- #5264 `48efbdb` show scriptSig signature hash types in transaction decodes. fixes #3166 (mruddy)
- #6719 `1a9f19a` Make HTTP server shutdown more graceful (Wladimir J. van der Laan)
- #6859 `0fbfc51` http: Restrict maximum size of http + headers (Wladimir J. van der Laan)
- #5936 `bf7c195` [RPC] Add optional locktime to createrawtransaction (Tom Harding)
- #6877 `26f5b34` rpc: Add maxmempool and effective min fee to getmempoolinfo (Wladimir J. van der Laan)
- #6970 `92701b3` Fix crash in validateaddress with -disablewallet (Wladimir J. van der Laan)
- #5574 `755b4ba` Expose GUI labels in RPC as comments (Luke-Jr)
- #6990 `dbd2c13` http: speed up shutdown (Wladimir J. van der Laan)
- #7013 `36baa9f` Remove LOCK(cs_main) from decodescript (Peter Todd)
- #6999 `972bf9c` add (max)uploadtarget infos to getnettotals RPC help (Jonas Schnelli)
- #7011 `31de241` Add mediantime to getblockchaininfo (Peter Todd)
- #7065 `f91e29f` http: add Boost 1.49 compatibility (Wladimir J. van der Laan)
- #7087 `be281d8` [Net]Add -enforcenodebloom option (Patrick Strateman)
- #7044 `438ee59` RPC: Added additional config option for multiple RPC users. (Gregory Sanders)
- #7072 `c143c49` [RPC] Add transaction size to JSON output (Nikita Zhavoronkov)
- #7022 `9afbd96` Change default block priority size to 0 (Alex Morcos)
- #7141 `c0c08c7` rpc: Don't translate warning messages (Wladimir J. van der Laan)
- #7312 `fd4bd50` Add RPC call abandontransaction (Alex Morcos)
- #7222 `e25b158` RPC: indicate which transactions are replaceable (Suhas Daftuar)
- #7472 `b2f2b85` rpc: Add WWW-Authenticate header to 401 response (Wladimir J. van der Laan)
- #7469 `9cb31e6` net.h fix spelling: misbeha{b,v}ing (Matt)

### Configuration and command-line options

- #6164 `8d05ec7` Allow user to use -debug=1 to enable all debugging (lpescher)
- #5288 `4452205` Added -whiteconnections=<n> option (Josh Lehan)
- #6284 `10ac38e` Fix argument parsing oddity with -noX (Wladimir J. van der Laan)
- #6489 `c9c017a` Give a better error message if system clock is bad (Casey Rodarmor)
- #6462 `c384800` implement uacomment config parameter which can add comments to user agent as per BIP-0014 (Pavol Rusnak)
- #6647 `a3babc8` Sanitize uacomment (MarcoFalke)
- #6742 `3b2d37c` Changed logging to make -logtimestamps to work also for -printtoconsole (arnuschky)
- #6846 `2cd020d` alias -h for -help (Daniel Cousens)
- #6622 `7939164` Introduce -maxuploadtarget (Jonas Schnelli)
- #6881 `2b62551` Debug: Add option for microsecond precision in debug.log (Suhas Daftuar)
- #6776 `e06c14f` Support -checkmempool=N, which runs checks once every N transactions (Pieter Wuille)
- #6896 `d482c0a` Make -checkmempool=1 not fail through int32 overflow (Pieter Wuille)
- #6993 `b632145` Add -blocksonly option (Patrick Strateman)
- #7323 `a344880` 0.12: Backport -bytespersigop option (Luke-Jr)
- #7386 `da83ecd` Add option `-permitrbf` to set transaction replacement policy (Wladimir J. van der Laan)
- #7290 `b16b5bc` Add missing options help (MarcoFalke)
- #7440 `c76bfff` Rename permitrbf to mempoolreplacement and provide minimal string-list forward compatibility (Luke-Jr)

### Block and transaction handling

- #6203 `f00b623` Remove P2SH coinbase flag, no longer interesting (Luke-Jr)
- #6222 `9c93ee5` Explicitly set tx.nVersion for the genesis block and mining tests (Mark Friedenbach)
- #5985 `3a1d3e8` Fix removing of orphan transactions (Alex Morcos)
- #6221 `dd8fe82` Prune: Support noncontiguous block files (Adam Weiss)
- #6124 `41076aa` Mempool only CHECKLOCKTIMEVERIFY (BIP65) verification, unparameterized version (Peter Todd)
- #6329 `d0a10c1` acceptnonstdtxn option to skip (most) "non-standard transaction" checks, for testnet/regtest only (Luke-Jr)
- #6410 `7cdefb9` Implement accurate memory accounting for mempool (Pieter Wuille)
- #6444 `24ce77d` Exempt unspendable transaction outputs from dust checks (dexX7)
- #5913 `a0625b8` Add absurdly high fee message to validation state (Shaul Kfir)
- #6177 `2f746c6` Prevent block.nTime from decreasing (Mark Friedenbach)
- #6377 `e545371` Handle no chain tip available in InvalidChainFound() (Ross Nicoll)
- #6551 `39ddaeb` Handle leveldb::DestroyDB() errors on wipe failure (Adam Weiss)
- #6654 `b0ce450` Mempool package tracking (Suhas Daftuar)
- #6715 `82d2aef` Fix mempool packages (Suhas Daftuar)
- #6680 `4f44530` use CBlockIndex instead of uint256 for UpdatedBlockTip signal (Jonas Schnelli)
- #6650 `4fac576` Obfuscate chainstate (James O'Beirne)
- #6777 `9caaf6e` Unobfuscate chainstate data in CCoinsViewDB::GetStats (James O'Beirne)
- #6722 `3b20e23` Limit mempool by throwing away the cheapest txn and setting min relay fee to it (Matt Corallo)
- #6889 `38369dd` fix locking issue with new mempool limiting (Jonas Schnelli)
- #6464 `8f3b3cd` Always clean up manual transaction prioritization (Casey Rodarmor)
- #6865 `d0badb9` Fix chainstate serialized_size computation (Pieter Wuille)
- #6566 `ff057f4` BIP-113: Mempool-only median time-past as endpoint for lock-time calculations (Mark Friedenbach)
- #6934 `3038eb6` Restores mempool only BIP113 enforcement (Gregory Maxwell)
- #6965 `de7d459` Benchmark sanity checks and fork checks in ConnectBlock (Matt Corallo)
- #6918 `eb6172a` Make sigcache faster, more efficient, larger (Pieter Wuille)
- #6771 `38ed190` Policy: Lower default limits for tx chains (Alex Morcos)
- #6932 `73fa5e6` ModifyNewCoins saves database lookups (Alex Morcos)
- #5967 `05d5918` Alter assumptions in CCoinsViewCache::BatchWrite (Alex Morcos)
- #6871 `0e93586` nSequence-based Full-RBF opt-in (Peter Todd)
- #7008 `eb77416` Lower bound priority (Alex Morcos)
- #6915 `2ef5ffa` [Mempool] Improve removal of invalid transactions after reorgs (Suhas Daftuar)
- #6898 `4077ad2` Rewrite CreateNewBlock (Alex Morcos)
- #6872 `bdda4d5` Remove UTXO cache entries when the tx they were added for is removed/does not enter mempool (Matt Corallo)
- #7062 `12c469b` [Mempool] Fix mempool limiting and replace-by-fee for PrioritiseTransaction (Suhas Daftuar)
- #7276 `76de36f` Report non-mandatory script failures correctly (Pieter Wuille)
- #7217 `e08b7cb` Mark blocks with too many sigops as failed (Suhas Daftuar)
- #7387 `f4b2ce8` Get rid of inaccurate ScriptSigArgsExpected (Pieter Wuille)

### P2P protocol and network code

- #6172 `88a7ead` Ignore getheaders requests when not synced (Suhas Daftuar)
- #5875 `9d60602` Be stricter in processing unrequested blocks (Suhas Daftuar)
- #6256 `8ccc07c` Use best header chain timestamps to detect partitioning (Gavin Andresen)
- #6283 `a903ad7` make CAddrMan::size() return the correct type of size_t (Diapolo)
- #6272 `40400d5` Improve proxy initialization (continues #4871) (Wladimir J. van der Laan, Diapolo)
- #6310 `66e5465` banlist.dat: store banlist on disk (Jonas Schnelli)
- #6412 `1a2de32` Test whether created sockets are select()able (Pieter Wuille)
- #6498 `219b916` Keep track of recently rejected transactions with a rolling bloom filter (cont'd) (Peter Todd)
- #6556 `70ec975` Fix masking of irrelevant bits in address groups. (Alex Morcos)
- #6530 `ea19c2b` Improve addrman Select() performance when buckets are nearly empty (Pieter Wuille)
- #6583 `af9305a` add support for miniupnpc api version 14 (Pavel Vasin)
- #6374 `69dc5b5` Connection slot exhaustion DoS mitigation (Patrick Strateman)
- #6636 `536207f` net: correctly initialize nMinPingUsecTime (Wladimir J. van der Laan)
- #6579 `0c27795` Add NODE_BLOOM service bit and bump protocol version (Matt Corallo)
- #6148 `999c8be` Relay blocks when pruning (Suhas Daftuar)
- #6588 `cf9bb11` In (strCommand == "tx"), return if AlreadyHave() (Tom Harding)
- #6974 `2f71b07` Always allow getheaders from whitelisted peers (Wladimir J. van der Laan)
- #6639 `bd629d7` net: Automatically create hidden service, listen on Tor (Wladimir J. van der Laan)
- #6984 `9ffc687` don't enforce maxuploadtarget's disconnect for whitelisted peers (Jonas Schnelli)
- #7046 `c322652` Net: Improve blocks only mode. (Patrick Strateman)
- #7090 `d6454f6` Connect to Tor hidden services by default (when listening on Tor) (Peter Todd)
- #7106 `c894fbb` Fix and improve relay from whitelisted peers (Pieter Wuille)
- #7129 `5d5ef3a` Direct headers announcement (rebase of #6494) (Pieter Wuille)
- #7079 `1b5118b` Prevent peer flooding inv request queue (redux) (redux) (Gregory Maxwell)
- #7166 `6ba25d2` Disconnect on mempool requests from peers when over the upload limit. (Gregory Maxwell)
- #7133 `f31955d` Replace setInventoryKnown with a rolling bloom filter (rebase of #7100) (Pieter Wuille)
- #7174 `82aff88` Don't do mempool lookups for "mempool" command without a filter (Matt Corallo)
- #7179 `44fef99` net: Fix sent reject messages for blocks and transactions (Wladimir J. van der Laan)
- #7181 `8fc174a` net: Add and document network messages in protocol.h (Wladimir J. van der Laan)
- #7125 `10b88be` Replace global trickle node with random delays (Pieter Wuille)
- #7415 `cb83beb` net: Hardcoded seeds update January 2016 (Wladimir J. van der Laan)
- #7438 `e2d9a58` Do not absolutely protect local peers; decide group ties based on time (Gregory Maxwell)
- #7439 `86755bc` Add whitelistforcerelay to control forced relaying. [#7099 redux] (Gregory Maxwell)
- #7482 `e16f5b4` Ensure headers count is correct (Suhas Daftuar)

### Validation

- #5927 `8d9f0a6` Reduce checkpoints' effect on consensus. (Pieter Wuille)
- #6299 `24f2489` Bugfix: Don't check the genesis block header before accepting it (Jorge Timón)
- #6361 `d7ada03` Use real number of cores for default -par, ignore virtual cores (Wladimir J. van der Laan)
- #6519 `87f37e2` Make logging for validation optional (Wladimir J. van der Laan)
- #6351 `2a1090d` CHECKLOCKTIMEVERIFY (BIP65) IsSuperMajority() soft-fork (Peter Todd)
- #6931 `54e8bfe` Skip BIP 30 verification where not necessary (Alex Morcos)
- #6954 `e54ebbf` Switch to libsecp256k1-based ECDSA validation (Pieter Wuille)
- #6508 `61457c2` Switch to a constant-space Merkle root/branch algorithm. (Pieter Wuille)
- #6914 `327291a` Add pre-allocated vector type and use it for CScript (Pieter Wuille)
- #7500 `889e5b3` Correctly report high-S violations (Pieter Wuille)


### Build system

- #6210 `0e4f2a0` build: disable optional use of gmp in internal secp256k1 build (Wladimir J. van der Laan)
- #6214 `87406aa` [OSX] revert renaming of Bitcoin-Qt.app and use CFBundleDisplayName (partial revert of #6116) (Jonas Schnelli)
- #6218 `9d67b10` build/gitian misc updates (Cory Fields)
- #6269 `d4565b6` gitian: Use the new bitcoin-detached-sigs git repo for OSX signatures (Cory Fields)
- #6418 `d4a910c` Add autogen.sh to source tarball. (randy-waterhouse)
- #6373 `1ae3196` depends: non-qt bumps for 0.12 (Cory Fields)
- #6434 `059b352` Preserve user-passed CXXFLAGS with --enable-debug (Gavin Andresen)
- #6501 `fee6554` Misc build fixes (Cory Fields)
- #6600 `ef4945f` Include bitcoin-tx binary on Debian/Ubuntu (Zak Wilcox)
- #6619 `4862708` depends: bump miniupnpc and ccache (Michael Ford)
- #6801 `ae69a75` [depends] Latest config.guess and config.sub (Michael Ford)
- #6938 `193f7b5` build: If both Qt4 and Qt5 are installed, use Qt5 (Wladimir J. van der Laan)
- #7092 `348b281` build: Set osx permissions in the dmg to make Gatekeeper happy (Cory Fields)
- #6980 `eccd671` [Depends] Bump Boost, miniupnpc, ccache & zeromq (Michael Ford)
- #7424 `aa26ee0` Add security/export checks to gitian and fix current failures (Cory Fields)

### Wallet

- #6183 `87550ee` Fix off-by-one error w/ nLockTime in the wallet (Peter Todd)
- #6057 `ac5476e` re-enable wallet in autoprune (Jonas Schnelli)
- #6356 `9e6c33b` Delay initial pruning until after wallet init (Adam Weiss)
- #6088 `91389e5` fundrawtransaction (Matt Corallo)
- #6415 `ddd8d80` Implement watchonly support in fundrawtransaction (Matt Corallo)
- #6567 `0f0f323` Fix crash when mining with empty keypool. (Daniel Kraft)
- #6688 `4939eab` Fix locking in GetTransaction. (Alex Morcos)
- #6645 `4dbd43e` Enable wallet key imports without rescan in pruned mode. (Gregory Maxwell)
- #6550 `5b77244` Do not store Merkle branches in the wallet. (Pieter Wuille)
- #5924 `12a7712` Clean up change computation in CreateTransaction. (Daniel Kraft)
- #6906 `48b5b84` Reject invalid pubkeys when reading ckey items from the wallet. (Gregory Maxwell)
- #7010 `e0a5ef8` Fix fundrawtransaction handling of includeWatching (Peter Todd)
- #6851 `616d61b` Optimisation: Store transaction list order in memory rather than compute it every need (Luke-Jr)
- #6134 `e92377f` Improve usage of fee estimation code (Alex Morcos)
- #7103 `a775182` [wallet, rpc tests] Fix settxfee, paytxfee (MarcoFalke)
- #7105 `30c2d8c` Keep track of explicit wallet conflicts instead of using mempool (Pieter Wuille)
- #7096 `9490bd7` [Wallet] Improve minimum absolute fee GUI options (Jonas Schnelli)
- #6216 `83f06ca` Take the training wheels off anti-fee-sniping (Peter Todd)
- #4906 `96e8d12` Issue#1643: Coinselection prunes extraneous inputs from ApproximateBestSubset (Murch)
- #7200 `06c6a58` Checks for null data transaction before issuing error to debug.log (Andy Craze)
- #7296 `a36d79b` Add sane fallback for fee estimation (Alex Morcos)
- #7293 `ff9b610` Add regression test for vValue sort order (MarcoFalke)
- #7306 `4707797` Make sure conflicted wallet tx's update balances (Alex Morcos)
- #7381 `621bbd8` [walletdb] Fix syntax error in key parser (MarcoFalke)
- #7491 `00ec73e` wallet: Ignore MarkConflict if block hash is not known (Wladimir J. van der Laan)
- #7502 `1329963` Update the wallet best block marker before pruning (Pieter Wuille)

### GUI

- #6217 `c57e12a` disconnect peers from peers tab via context menu (Diapolo)
- #6209 `ab0ec67` extend rpc console peers tab (Diapolo)
- #6484 `1369d69` use CHashWriter also in SignVerifyMessageDialog (Pavel Vasin)
- #6487 `9848d42` Introduce PlatformStyle (Wladimir J. van der Laan)
- #6505 `100c9d3` cleanup icons (MarcoFalke)
- #4587 `0c465f5` allow users to set -onion via GUI (Diapolo)
- #6529 `c0f66ce` show client user agent in debug window (Diapolo)
- #6594 `878ea69` Disallow duplicate windows. (Casey Rodarmor)
- #5665 `6f55cdd` add verifySize() function to PaymentServer (Diapolo)
- #6317 `ca5e2a1` minor optimisations in peertablemodel (Diapolo)
- #6315 `e59d2a8` allow banning and unbanning over UI->peers table (Jonas Schnelli)
- #6653 `e04b2fa` Pop debug window in foreground when opened twice (MarcoFalke)
- #6864 `c702521` Use monospace font (MarcoFalke)
- #6887 `3694b74` Update coin control and smartfee labels (MarcoFalke)
- #7000 `814697c` add shortcurts for debug-/console-window (Jonas Schnelli)
- #6951 `03403d8` Use maxTxFee instead of 10000000 (MarcoFalke)
- #7051 `a190777` ui: Add "Copy raw transaction data" to transaction list context menu (Wladimir J. van der Laan)
- #6979 `776848a` simple mempool info in debug window (Jonas Schnelli)
- #7006 `26af1ac` add startup option to reset Qt settings (Jonas Schnelli)
- #6780 `2a94cd6` Call init's parameter interaction before we create the UI options model (Jonas Schnelli)
- #7112 `96b8025` reduce cs_main locks during tip update, more fluently update UI (Jonas Schnelli)
- #7206 `f43c2f9` Add "NODE_BLOOM" to guiutil so that peers don't get UNKNOWN[4] (Matt Corallo)
- #7282 `5cadf3e` fix coincontrol update issue when deleting a send coins entry (Jonas Schnelli)
- #7319 `1320300` Intro: Display required space (Jonas Schnelli)
- #7318 `9265e89` quickfix for RPC timer interface problem (Jonas Schnelli)
- #7327 `b16b5bc` [Wallet] Transaction View: LastMonth calculation fixed (crowning-)
- #7364 `7726c48` [qt] Windows: Make rpcconsole monospace font larger (MarcoFalke)
- #7384 `294f432` [qt] Peertable: Increase SUBVERSION_COLUMN_WIDTH (MarcoFalke)

### Tests and QA

- #6305 `9005c91` build: comparison tool swap (Cory Fields)
- #6318 `e307e13` build: comparison tool NPE fix (Cory Fields)
- #6337 `0564c5b` Testing infrastructure: mocktime fixes (Gavin Andresen)
- #6350 `60abba1` add unit tests for the decodescript rpc (mruddy)
- #5881 `3203a08` Fix and improve txn_doublespend.py test (Tom Harding)
- #6390 `6a73d66` tests: Fix bitcoin-tx signing test case (Wladimir J. van der Laan)
- #6368 `7fc25c2` CLTV: Add more tests to improve coverage (Esteban Ordano)
- #6414 `5121c68` Fix intermittent test failure, reduce test time (Tom Harding)
- #6417 `44fa82d` [QA] fix possible reorg issue in (fund)rawtransaction(s).py RPC test (Jonas Schnelli)
- #6398 `3d9362d` rpc: Remove chain-specific RequireRPCPassword (Wladimir J. van der Laan)
- #6428 `bb59e78` tests: Remove old sh-based test framework (Wladimir J. van der Laan)
- #5515 `d946e9a` RFC: Assert on probable deadlocks if the second lock isnt try_lock (Matt Corallo)
- #6287 `d2464df` Clang lock debug (Cory Fields)
- #6465 `410fd74` Don't share objects between TestInstances (Casey Rodarmor)
- #6534 `6c1c7fd` Fix test locking issues and un-revert the probable-deadlines assertions commit (Cory Fields)
- #6509 `bb4faee` Fix race condition on test node shutdown (Casey Rodarmor)
- #6523 `561f8af` Add p2p-fullblocktest.py (Casey Rodarmor)
- #6590 `981fd92` Fix stale socket rebinding and re-enable python tests for Windows (Cory Fields)
- #6730 `cb4d6d0` build: Remove dependency of bitcoin-cli on secp256k1 (Wladimir J. van der Laan)
- #6616 `5ab5dca` Regression Tests: Migrated rpc-tests.sh to all Python rpc-tests.py (Peter Tschipper)
- #6720 `d479311` Creates unittests for addrman, makes addrman more testable. (Ethan Heilman)
- #6853 `c834f56` Added fPowNoRetargeting field to Consensus::Params (Eric Lombrozo)
- #6827 `87e5539` [rpc-tests] Check return code (MarcoFalke)
- #6848 `f2c869a` Add DERSIG transaction test cases (Ross Nicoll)
- #6813 `5242bb3` Support gathering code coverage data for RPC tests with lcov (dexX7)
- #6888 `c8322ff` Clear strMiscWarning before running PartitionAlert (Eric Lombrozo)
- #6894 `2675276` [Tests] Fix BIP65 p2p test (Suhas Daftuar)
- #6863 `725539e` [Test Suite] Fix test for null tx input (Daniel Kraft)
- #6926 `a6d0d62` tests: Initialize networking on windows (Wladimir J. van der Laan)
- #6822 `9fa54a1` [tests] Be more strict checking dust (MarcoFalke)
- #6804 `5fcc14e` [tests] Add basic coverage reporting for RPC tests (James O'Beirne)
- #7045 `72dccfc` Bugfix: Use unique autostart filenames on Linux for testnet/regtest (Luke-Jr)
- #7095 `d8368a0` Replace scriptnum_test's normative ScriptNum implementation (Wladimir J. van der Laan)
- #7063 `6abf6eb` [Tests] Add prioritisetransaction RPC test (Suhas Daftuar)
- #7137 `16f4a6e` Tests: Explicitly set chain limits in replace-by-fee test (Suhas Daftuar)
- #7216 `9572e49` Removed offline testnet DNSSeed 'alexykot.me'. (tnull)
- #7209 `f3ad812` test: don't override BITCOIND and BITCOINCLI if they're set (Wladimir J. van der Laan)
- #7226 `301f16a` Tests: Add more tests to p2p-fullblocktest (Suhas Daftuar)
- #7153 `9ef7c54` [Tests] Add mempool_limit.py test (Jonas Schnelli)
- #7170 `453c567` tests: Disable Tor interaction (Wladimir J. van der Laan)
- #7229 `1ed938b` [qa] wallet: Check if maintenance changes the balance (MarcoFalke)
- #7308 `d513405` [Tests] Eliminate intermittent failures in sendheaders.py (Suhas Daftuar)
- #7468 `947c4ff` [rpc-tests] Change solve() to use rehash (Brad Andrews)

### Miscellaneous

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

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
- Florian Schmaus
- Forrest Voight
- Gavin Andresen
- Gregory Maxwell
- Gregory Sanders / instagibbs
- 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
- Matt Bogosian
- Matt Corallo
- Matt Quinn
- Micha
- Michael
- Michael Ford / fanquake
- Midnight Magic
- Mitchell Cash
- mrbandrews
- mruddy
- Nick
- Patrick Strateman
- Paul Georgiou
- Paul Rabahy
- Pavel Janík / paveljanik
- 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
- Thomas Kerin
- Tom Harding
- tulip
- unsystemizer
- Veres Lajos
- Wladimir J. van der Laan
- xor-freenet
- Zak Wilcox
- zathras-crypto

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

Is this the first version with opt-in RBF ? From which version SegWit will come ?

Yes.
Segwit will come in 0.12.x. I'm assuming that it will be the next version (unless some things need to be fixed sooner).

segwit is scheduled for april, and before the halving all the features will kick in

edit.... why there is still not the digital sign for the exe? it's not good when i click on the exe and it say that is not safe, it can discourage newbie...

digital sign cost like hundred dollars, not so much

Wow! It looks good, but I don't understand all the changes. I'll upgrade and run it without pruning. I was also thinking of blocking SPV peers - is this a good idea?

This might help:
Let's also not forget the wast amount of fixes that are listed above.

They removed the --with-libressl build option.

Great job to all, well done.  i just fired it up. Many Thanks  ;D

I'm now running it. Upgrade was painless after I had backed up the blockchain. :)

Now to play with it. Should I disable SPV peers?

Congratulations everyone. Keep up the hard work.

Core team did a really fine job with this release... Updating my node while writing this :)

gz! great release with great new features! Keep the good work guys :)
Anyone know when we will have and a ubuntu package in ppa?

All great improvements and new features, but it lacks the one we need the most, moar transactions!

Does it open much quicker than the last release? Sick to death of occasionally getting 'Activating Best Chain' & not opening for literally sometimes 15 minutes or more.

Yeah I actually just made a thread about this. The startup time is real quick compared to the old version. I had no "Activating Best Chain" for an hour and the verification process was fast, now im syncing the blockchain and unfortunately the download speed has not increased for me too much, but at least now I can open the software rather quick.

Do you have to re-download  the entire blockchain to upgrade from 0.11.2 to 0.12.0

No.

Good, don't know if I could face that shit another time.

Do we get any kind of information in the log when this happens? Eg. something like "mempool reached max size, evicting 2 transactions, effective minimum relay fee is now 0.00001200 BTC".



I understand that this brings no benefit to those of us who are already using tor, correct? "Using tor" like in:

Not sure what you mean that it isn't signed. It looks signed to me.

This feature could be of more use in the future, especially if individual nodes will run 'dual stack' i.e. on clearnet and through Tor.

I've started a thread on that basis here: https://bitcointalk.org/index.php?topic=1374919.0

- How-to Guide: Set-up Tor on Linux (Ubuntu) and connect Bitcoin
 

Awesome!
Downloaded and running it now.
Runs quick and pretty smooth. :)
Great work by the devs.Thanks for that!

As a general rule, if/when one starts to run out of space, one probably does require some more space!   ;D
 

This option was removed because the only purpose it served was to override _disabling_ building with libressl, now that OpenSSL's exact behavior is no longer normative to the Bitcoin consensus. Libressl builds are no longer disabled by default.



commit 59783884766d00866e190ba5ae761916e932df10
Author: Wladimir J. van der Laan <laanwj@gmail.com>
Date:   Mon Sep 28 16:06:38 2015 +0200

    build: remove libressl check
   
    Now that BIP66 passed, OpenSSL is no longer directly part of the
    consensus. What matters is that DER signatures are correctly parsed, and
    secp256k1 crypto is implemented correctly (as well as the other
    functions we use from OpenSSL, such as random number generation)
   
    This means that effectively, using LibreSSL is not a larger risk than
    using another version of OpenSSL.
   
    Remove the specific check for LibreSSL.
   
    Includes the still-relevant part of #6729: make sure CHECK_HEADER is
    called using the right CXXFLAGS, not CFLAGS (as AC_LANG is c++).

So got a question from a wallet user, should i:

a.) run in prune mode all the time  (leave qt running all the time)

b.) run qt only when i need to access my wallet

All i want is fast access to my 5 year old wallet with 100 transactions in it, included my 2 mined blocks from 2011.

Currently running a full node with port blocked on a poor netbook and  a usb hd, takes ~ 1 hour to re sync to access my wallet.

What is the minimum download data i will need if i shut down the qt and load it 6 months later to access my wallet running in prune mode?

Thanks

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Pruning does not effect the amount of data downloaded, so pruning would not help you at all, you would still need to fully sync by downloading all of the blocks. It is just that you won't be storing all of those blocks.

With 0.12 it is possible to use wallet functionality in pruned mode.
This can reduce the disk usage from currently around 60 GB to
around 2 GB.

Just to clarify whats the difference between downloading and storing?

Seems to me  i will only need to "download" 2 gb of data in order to access wallet.

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Downloading is the amount of data that passes through your network. Storing is actually writing that data to the disk to be permanent.

Think of it this way. You are downloading all 60 Gb of the blockchain and then 58 Gb of it is deleted. This is essentially what happens, except it happens on the fly so that you don't need 60 Gb of space, it deletes old blocks as new blocks come in so that at any time, the most storage space actually used is 2 Gb.

really interesting and cool to know abt the new version. will test that later for sure

I have installed the 0.12.0 version and finally I am healed from the ultra slow block syncing that I was suffering from in the previous updates. That's a great step forwards to me. :)

Ya testing it on desktop computer as i type this, i did notice, its doing a week of a work under 10 seconds :) so ya its like downloading 60 gb of data and only storing the last 2 gb :) so that answers my question, best to keep the qt running 24/7.

Thanks for the help

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I think this might be the most anticipated change among general users of core (some of these changes are too technical for my, and I'm a fairly tech-savy person).  I'll probably try a pruned wallet on one node just to see how it feels vs. my full node.

well got a question (again) and a comment, first the question, can i run 2 qt nodes on the same pc at the same time (ie 1 pruned 1 full node) in different locations of course, want to keep a "full" node just in case, also love the prune version, it picks up right were it left off at. But was afraid the 2 data streams might get confused, windows register error or something running 2 of the same qt at once, any thoughts?

Thanks Core Team :)

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Ah got a problem, just tried loading a wallet.dat file of my hot wallet and reloading in prune mode, got an error says cant access wallet.dat goes past its 2 gb limit and i need to reindex, thought that was the whole point of the .12 update and wallet users being able to access our wallets..  Am i doing something wrong?

It is possible, just that you need to use a separate data directories and if you want to have incoming connections to both, one of them will need to listen on a port different from 8333 in order to accept incoming connections.

The problem with pruning is that if you load a wallet whose latest sync height is older than the oldest block you have, you will need to re-download the entire blockchain in order to be able to rescan it and make sure that any transactions that occurred in the blocks between your wallet's latest block and your oldest pruned block. However, the idea is that you won't be loading new wallets into a pruned node and since it will pick up pruning and syncing from where it left off, this should never become a problem.

Your solution, since you have a full node as well, is to just load the wallet into the full node, let it sync, then close it and load it into the pruned node.

Are you talking about loading my hot wallet.dat file into the full node sync it. Then prune it , leaving the wallet.dat file in the data folder all the time?
If so don't want to do that my cold wallet is older and has stored btc in it, that i want "offline".

So is there anyway to use an cold wallet/offline in prune mode seeing it wont be loaded for long periods of time?

Thanks

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No, you should load your hot wallet into the full node to sync it. Then move it from your full node to your pruned node and start your pruned node. It should work then.

So long as when you have your cold wallet and pruned node go offline that they are both synced to the same height. Once you bring them back online, then they will automatically sync. However, if you just have your cold wallet offline and your pruned node online, then your pruned node will need to redownload and rescan in order to be able to spend from your cold wallet.

Think i got it, guess i should had know better :) Thanks for all the help.

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Upgraded earlier, everything seems to be ok.

I've had no problems with loading 0.12.0, and it does seem to be a bit faster. I'm still limited to 8 peers, but the interesting thing is - I've got 2 on 0.12.0, 2 running classic, and 4 running old Satoshi software. I hope this means that we will go forward with core.

I want to continue doing it manually. Will these settings give me back control?

Also any word on PPA?

I didn't touch it, and connectivity is still there:


So I'm not touching it either :)

Something has been trying to connect to my tor over port 80 and I think it might have started at .12 beta

 x 23:57:04 [WARN] Socks version 80 not recognized. (Tor is not an http proxy.)
 x   [3504334 duplicates hidden]

the exe is not signed, try to launch it in windows and you will see the usual alert message

also, to enable pruning i must remove the blockchain data first? i thought when enabling it he just delete all data if MB = 0

No one likes microshits proprietary certs

The installer (under windows 64 bit) is digital signed, and to enable pruning it will auto prune when it loads and re syncs, just make sure you have your wallet.dat file loaded first, if you don't you will have to re-download/re sync to match your wallets txid's  <.. and need to keep the wallet.dat file loaded all time while in pruning mode.

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yeah it removed all the giga, ok know i accidentally clicked on the fee per kb, how to undo this change? i want to see fee in custom via "satoshi" unit not per kb

With 0.11.2 I was getting what seemed to be a fragmented heap after running for weeks non-stop with a high number of connections. The workaround was a weekly restart. Let's see if this problem is fixed.

Having issues with my 0.12 node :( It shut itself down during the night, just booted it up now and it says the block database is corrupted... It's checking blocks now, let's see how this goes. Wierd that this happened after updating and not right away, still trying to figure out what's happening.

Happened to me too just yesterday.  Core crashed and I booted it back up and had a corrupted database, so I told it to rebuild and it crashed again.  Then it wouldn't get past the loading screen without crashing, so I deleted everything in my \Bitcoin\ directory and reinstalled Core 0.12 and the same thing kept happening, crash at the loading screen.  I tried installing my \Bitcoin\ directory on another physical drive and still same thing happened.  After deleting and reinstalling about 5 times it finally booted up and started syncing again.  I think this is my computer telling me it's too old for this sh.t any more.

beware anyone and dont delete the wallet.dat because this is that keep your bitcoins

So v0.12 is a total bust for me.  It crashed once more and I cannot get it to start up no matter what.  It sometimes makes it to "checking addresses" on the loading screen, but never any further.  Sometimes it crashes as soon as the loading screen appears.  I went back to 0.11.2 and it loads just find so it is a bug specific to 0.12.

Here are a few of my logs from the crashes, you can see the program just stops with no indication of any sort of error.




I give 0.12 a fail stamp, sorry.  :(

So no one else experienced the "0.12.0 won't start up" problem like I have?  It's a weird issue that only affects 0.12 and I can't understand it.

So I am still running 0.11.2, and I minimized it to the taskbar, however the taskbar icon disappeared and now I cannot bring core up.  bitcoin-qt.exe is still running per my task manager, and my node is still up per bitnodes, but I guess I'll just have to wait for the program to crash (like it always does) before I can get the gui up again.

You should probably take this to another thread.

Anyways, what OS are you using and what are the specs of your system?

It's an older computer I built years ago, still runs XP.  The OS could be an issue, but I doubt the hardware is (decent proc, plenty of RAM and hd space).  One of these days I'll get around to building a new machine.  I also need to turn my old laptop into a Linux machine, that would be the one to run my node ideally I think.  But in the mean time I would love some ideas what was changed in 0.12 that now makes it unusable on my computer.

The problem is XP. There are known problems with 0.12 with XP. See https://github.com/bitcoin/bitcoin/issues/7674 and https://github.com/bitcoin/bitcoin/issues/7639. However i don't think it will be fixed since XP support from Microsoft has ended and thus fixing an XP only problem is not worth it to the core devs. See https://github.com/bitcoin/bitcoin/issues/7681 for the discussion about that.

Perfect, that is exactly my issue.  Thanks for sharing the link, I'll follow that and see what develops.  There are still so many XP users out there that it would be a shame if bitcoin core was not longer able to be run on it.

If I were a core developer I wouldn't care about any people using Windows XP and reporting problems. Sorry but XP is a security risk from my pov and EOL since nearly 2 Years!
For some people hard but the truth...

I've never had an issue with the new version. I used to get my blockchain corrupted in the past for some reason, now it's never happened again. It boots so much faster too. Probably the best release yet.

I want to know what is the best -dbcache to use depending on your ram tho, to see if I can make it sync faster.

Sorry, but Win10 is way more of a "security risk" than a well maintained and firewalled XP system, but Win10 still gets support so go figure...

Going to try 0.12.1 and see if it has the same crash syndrome, hopefully not.

What about win7?

0.12.1 will probably have the same problem because no solution was written and included in Bitcoin Core.