Caramelization

A long-awaited Neo 2.0 update for neo-go that fixes a lot of subtle little
differences in VM and syscalls behavior compared to C# node that resulted in
storage state mismatches between two nodes. This release makes neo-go fully
compatible with public testnet and mainnet chains, for every transaction in
every block you get the same result.

But it's not just about bugs, as it's been quite a long development cycle,
we've also included some interesting new features like notification subsystem,
neo-debugger compatibility and BadgerDB support. Smart contract compiler and
interop packages were also updated making neo-go even better for developing
real-world complex smart contracts.

New features:

• support for for loops with no condition was added to the compiler (#799)
• compiler can now emit debug information compatible with neo-debugger (#804,
  #829)
• experimental BadgerDB support was added (#839)
• support for abi.json files generation was added for contract deployment
  with NEO-Express (#916)
• RPC over websocket connections is now supported both by the server (with
  ws://$SERVER:$PORT/ws URL) and client (WSClient structure, #921)
• notification subsystem was added for RPC server and client (using websocket
  connections, #895)
• interop package now has a complete set of syscalls available (#795, #956)
• push command was added to VM CLI (#967)
• diff dumps are now supported in db restore CLI command (#991)

Behavior changes:

• due to DB format changes you'll need to resynchronize your node from
  scratch (and it'll also update its state to a more proper one)
• runtime.Notify interop now accepts varargs (#825)
• compiler's --debug parameter is now used for debug information generation,
  use --verbose to get more internal compiler's messages (#829)
• compiler now outputs hex-encoded contract's bytecode only with --verbose
  option (#829, previously it was always printed)
• RPC client's representation of GetBlock results changed significantly (#951)
• some interop functions changed their in/out types to a more proper ones
  (#956, though previous ones didn't really work, so no current code should
  notice that)
• skip parameter to db restore CLI command was replaced by start
  (#991), when using full (non-diff) NGD dumps with short (-s) form they're
  compatible, but start (as a block index) makes more sense for diff dumps

Improvements:

• (*Stack).PushVal in vm now supports all types of integers (#776)
• state.AppExecResult now stores stack in binary representation (#782)
• vm.NewBigIntegerItem now accepts int64 parameter (#788)
• RPC client tests were added (#716)
• buffer reuse added for persisting temporary changes which improved block
  handling speed (#772)
• significant RPC server package refactoring was done (#753)
• BoltDB was updated to v1.3.4 (#793)
• Go 1.14 is now supported (#775)
• serialization/deserialization tests were unified (#802)
• emit package now has Array and AppCallWithOperationAndArgs methods for
  easier script creation (#803)
• persisting from MemCachedStore to MemCachedStore was optimized which
  allowed to gain 10% improvement in block import time for 1.5M mainnet
  blocks (#807)
• storage.Find usage example was added (#795)
• VM stack item tests were improved (#812)
• config directory now only contains configuration files, no Go code (#423,
  #816)
• local variables are counted more accurately now in the compiler leading to
  less waste in script runtime (#815)
• NEP5 example was extended with minting function making it a bit more usable
  (#823)
• DAO was refactored away into its own package from core (#832)
• additional tests were added for bitwise and numeric VM operations (#833)
• tests for VM CALL* instructions were added (#833)
• consensus message parsing was split into two parts so that ordinary nodes
  won't touch CN's data (#862)
• contract's metadata was moved into smartcontract package from rpc (#916)
• interop packages documentation was extended (#956)
• Docker build was fixed to use Makefile (#981)

Bugs fixed:

• integer stack values were not following C# node format when being converted
  to JSON (#770)
• vm now uses truncated division to match C# node behavior for negative
  integers (#773)
• getapplicationlog and other RPC calls now convert Uint160 to JSON the same
  way C# node does (#769)
• asset state JSON representation now follows the same format as C# node uses
  (with proper field names for 'id' and 'type' and without 'fee' add
  'address' fields, #785, #819)
• nextconsensus field in getblockheader RPC call answer was using hex
  representation instead of address (#763)
• getcontractstate RPC call implementation was using wrong format for
  script field in answer (#763)
• getnep5balances RPC call implementation was using wrong name for
  balance field in answer (#763)
• getvalidators RPC call was using non-compliant validators keys format in
  its answer (#763)
• potential problems with GAS parameter handling in CLI (#790)
• contract init CLI command was not working correctly (#792)
• RPC calls now accept integer parameters in JSON strings which fix some
  incompatibilities (#794)
• CALLI VM instruction was using wrong offset (#791, #798)
• vm Map stack item for using different serialization format from C# node
  (#806, #808)
• invoke* RPC calls were returning stack in Stack element rather than more
  compliant stack (#805)
• slices of compound types were treated wrong by the compiler (#800)
• wrong code was generated for struct variables declarations by the compiler
  (#800)
• RPC client was incorrectly processing GetRawTransactionVerbose,
  GetBlockVerbose, GetBlockHeader, GetTxOut and ValidateAddress call results
  (#789)
• type-specific transaction data was completely missing in getrawtransaction
  RPC call verbose output (#585)
• documentation for wallet CLI commands was fixed to follow renames made by
  previous version (#814)
• panic in map-containing notifications processing (#809)
• VM Map implementation now has deterministic iteration order (#818)
• MOD instruction behavior was fixed to follow neo-vm (#826)
• negative arguments are now accepted for SHL/SHR VM instructions (#827)
• improper in-block cache propagation leading to storage state differences
  with C# node (#821, #817)
• CLI didn't check for mandatory method parameter presence for
  invokefunction command (#828)
• wrong code generated by the compiler for return statements with no
  parameters (#929)
• wrong code generated by the compiler for multiple function arguments with
  one type specification (#935)
• NEP5 example contained wrong address check (#945)
• improper code generated by the compiler for op= assignments to struct
  fields and slice elements (#954)
• Storage.Find elements order was adjusted to match C# node implementation
  and eliminate state differences resulting from that (#822, #977, #988,
  #994)
• step command wasn't really working in VM CLI (#967)
• PICKITEM instruction implementation was fixed to reject improper input
  argument types (#965, #967)
• Runtime.CheckWitness was fixed to only accept compressed keys (#968, #971)
• input data length check was added to (*PublicKey).DecodeBytes (#971)
• VM reference counting for SETITEM instruction was fixed (#973)
• Map VM stack item can now be converted to Boolean (#974)
• Structs were not cloned by SETITEM instruction implementation (#972, #975)
• GetUnspentCoins syscall implementation was fixed to return array (#978,
  #979, #984)

Comprehension

Functionally complete NEO 2.0 node implementation, this release can be used as
a drop-in replacement for C# node in any setting. It features full RPC
functionality support and full set of wallet operations. As usual, there
also was a number of bugs fixed, the node stability improved and some great
optimizations were also done (especially concentrated around DB interactions),
so even though this release has more functionality than ever (and it stores a
lot more chain data than ever) it at the same time imports blocks faster than
the previous one.

Of course we will make additional maintenance releases for NEO 2.0 when
needed, but following this release we'll concentrate more on NEO 3.0 features
and catching up with recent community developments around that.

New features:

• WIF and NEP2 keys import/export into/from the wallet (#685)
• multisig accounts import into the wallet (#685)
• additional key generation for existing wallets (#685)
• support for break and continue statements in the compiler (#678)
• getblocksysfee RPC method support (#341)
• getapplicationlog RPC method support (#500, #754)
• getclaimable RPC method support (#694)
• gas claiming support in wallet CLI (#694)
• asset transfer commands in wallet CLI (#694, #706)
• getrawmempool RPC method support (#175)
• RPC client support for all methods implemented in neo-go's server (#586,
  #715, #694, #723, #750)
• getblockheader RPC method support (#722)
• getnep5balances and getnep5transfers RPC methods support (#498, #751)
• gettransactionheight RPC method support (#713)
• submitblock RPC method support (#344)
• getvalidators RPC method support (#714)
• support for switch fallthrough statements in the compiler (#628)
• a set of NEP5* methods added to RPC client for convenient NEP5 contract
  calls (#728, #764)
• NEP tokens balance querying and transfers support for CLI (#728, #757)
• getunclaimed RPC method support (#712)
• contract import was added to the wallet CLI command set (#757)
• key removal added to the wallet CLI command set (#757)
• https support for RPC server (#702)

Behaviour changes:

• gas parameter for deployment no longer specifies full gas to be added into
  the transaction, it now only specifies the network fee part while system
  fee part is computed automatically based on contract's metadata (#747)
• contract deployment and invocation from CLI is now integrated with the
  wallet subsystem, WIF parameter support was dropped (#747)
• wallet subcommands were renamed, create became init and
  create-account became simple create (#757)
• DB format was changed several times during this release cycle, so please
  resynchronize your chains

Improvements:

• improved and extended wallet package (#685, #694, #706, #728, #757)
• refactored RPC package (dividing it into smaller subpackages, #510, #689)
• GroupInputsByPrevHash is no longer tied to Transaction, allowing its
  wider use (#696)
• more efficient transaction.InOut type is used for References (#696,
  #733)
• RPC client's SendToAddress was renamed to TransferAsset to better
  reflect its purpose (#686)
• P2P server's graceful shutdown with connection closing (#691)
• broadcasted transaction batching was added improving network efficiency
  (#681)
• dropped duplicating rpc.StackParamType in favor of improved
  smartcontract.ParamType (#690, #706)
• trigger types moved to their own trigger package (#690)
• all Go packages were moved from github.com/CityOfZion to
  github.com/nspcc-dev where they technically already reside since August
  2019 (#710)
• NEP5 balances and transfers tracking was added to Blockchain (#723, #748)
• optimized transaction inputs/outputs/results verification (#743)
• SpentCoin and UnspentCoin structures were merged and moved into state
  package (#743)
• AddVerificationHash method was added to Transaction to simplify
  attributes management (#752)

Bugs fixed:

• getpeers RPC request was not returning unconnected and bad peers (#676)
• RPC client was not reporting real error from the answer in case of HTTP
  error (#676)
• potential race in Seek implementation for MemoryStore (#693)
• improper handling of more than 64K branching points in the compiler (#687)
• Enrollment transactions verification didn't check for validator key (#696)
• Claim transaction witness check might miss some hashes from Inputs (#696)
• double Claim verification was missing (#696)
• network fee calculation was completely broken (#696)
• mempool's Remove might drop wrong transaction (#697)
• missing double claim verification for mempool transactions (#697)
• server deadlock upon reaching connection limit (#691)
• wrong logic short-circuiting by compiler in complex conditions (#699, #701)
• AddHeaders method was not verifying headers in any way (#703)
• missing Claim amount verification (#694)
• bogus error returned from GetValidators when processing transfers to
  (yet) unexisting accounts (#694)
• Claim and Miner transactions network fee was wrong (#694)
• negative outputs were allowed in transactions, but shouldn't (#694)
• smart contract invocation CLI command failed to process some parameters
  correctly (#719)
• fatal error on concurrent access to Blockchain internal variable (#720)
• Invocation transactions missed some decoding checks (#718)
• it was allowed to have fractional GAS in Invocation transactions (which is
  interpreted as system fee), but it shouldn't (#718)
• system fee calculation for Invocation transactions was incorrect (#718)
• Transaction JSON unmarshalling was processing Outputs and Witnesses
  incorrectly (#706)
• panic on server shutdown in case it's not fully started yet (#721)
• sendrawtransaction RPC method implementation was not following error
  codes convention (#724)
• interop implementations were using wrong byte order for returned hashes
  leading to storage state differences at mainnet's block 2025204 (#727)
• getblock verbose response format was not following official documentation
  (#734)
• contract deployment could fail with no error returned (#736)
• max contract description limit was wrong, leading to deployment failures
  (#735)
• compiler didn't properly clean up stack on return or break in some
  situations (#731)
• deadlock in discovery service (#741)
• missing dynamic APPCALL support (#740)
• EQUAL opcode implementation was not comparing different stack item types
  correctly (#745, #749)
• RPC error on contract invocation when Hash160 is being passed into it
  (#758)
• absent any ping timeouts configuration the node was constantly pinging its
  neighbours (#680)
• contract's state migration was not done properly (#760)
• db import with state dump was not saving dumps correctly on interruption
  and was now resuming writes to dump files correctly after restart (#761)
• incomplete State transaction verification (#767)
• missing Owner signature check for Register transaction (#766)
• incomplete Issue transaction verification and mempool conflicts check
  (#765)

Cotransduction

This is the first release than can successfully operate as a Testnet CN
bringing with it fixed voting system implementation, policying support and
other related fixes. It also contains RPC improvements and updates to the
compiler.

New features:

• Go smart contracts can now use variables for struct fields initialization
  (#656)
• for range loops support in the compiler (#658)
• subslicing support for []byte type (#654)
• block's storage changes dump support similar to NeoResearch's storage audit
  (#649)
• gettxout RPC method support (#345)
• getcontractstate RPC method support (#342)
• getstorage RPC method support (#343)
• GetChangeAddress function in the wallet (#682)
• basic policying was implemented allowing to configure
  MaxTransactionsPerBlock, MaxFreeTransactionsPerBlock,
  MaxFreeTransactionSize and FeePerExtraByte (#682)

Behaviour changes:

• consensus process now only start when server sees itself synchronized with
  the rest of the network (see (*Server).IsInSync method, #682)
• default testnet and mainnet configurations now contain policer settings
  identical to default SimplePolicy C# plugin (#682), privnet is not changed

Improvements:

• keys.PublicKey now has Cmp method available (#661)
• core now exports UtilityTokenID and GoverningTokenID functions (#682)
• miner transactions generated by consensus process now properly set outputs
  based on block's transactions fees (#682)
• (*Blockchain).IsLowPriority now takes fee (Fixed8) as an input (#682)
• mempool's GetVerifiedTransactions and TryGetValue now also return
  transaction's fee
• DBFT logging was improved
• keys package no longer has Signature methods, they were replaced with more
  useful GetScriptHash (#682)

Bugs fixed:

• compiler produced wrong code if there was some data containing byte 0x62 in
  the program (#630)
• answer to the getblock RPC method was not following the specification in
  multiple places (#659)
• State transaction's descriptors were not encoded/decoded correctly (#661)
• keys.PublicKeys slice was not decoded properly (#661)
• 'Registered' descriptor of State transaction was not decoded correctly
  (#661)
• voting processing and validators election was fixed to follow C#
  implementation (#661, #512, #664, #682)
• deadlock in network subsystem on disconnect (#663)
• RPC answers with transactions were not following the specification in fields
  names (#666)
• segmentation fault when checking references of bad transactions (#671)
• getassetstate and getrawtransaction RPC methods were not returning
  error properly when missing asset or transaction (#675)
• consensus RecoveryMessage encoding/decoding wasn't correct (#679)
• DBFT was not reinitialized after successful chain update with the new block
  received from other peers (#673)
• DBFT timer was extended too much, not following the C# implementation (#682)

Confabulation

Bugfix and small refactoring release, though it's the first one to include
improved CHECKMULTISIG implementation that is ~20% faster.

Improvements:

• parallel CHECKMULTISIG implementation improving this instruction speed by
  around 20% (#548)
• bytecode emitting functions moved to separate package, avoiding old
  duplicate code and improving testing (#449, #534, #642)
• AppCall interop now accepts variable number of arguments (#651)
• more logging and info level from consensus subsystem, following neo-cli
  behaviour

Bugs fixed:

• compiler-emitted integers were using wrong format (#642)
• FreeGasLimit configuration set to zero was not really disabling gas limits
  (#652)
• stale disconnected peers could cause networking subsystem deadlock (#653)
• transaction reverification (on new block processing) could lead to
  blockchain deadlock for non-standard verification contracts (#655)

Contextualization

Exactly one bug fixed relative to the 0.72.0:

• testnet synchronization failed at block 713985 because of wrong
  notification generated by the invocation transaction (#650)

Crystallization

Starting at the end of the year 2019 we've spent a lot of effort to
stress-test our node with transaction load and this allowed us to uncover
some problems in various parts of the system. This release addresses all of
them and brings with it updated networking, consensus and mempool components
that can handle quite substantial transaction traffic and successfully produce
new blocks while being stressed. There are also important updates in VM that
fix incompatibilities with C# node and interesting improvements in compiler
based on our experience porting neofs smart contract to Go.

New features:

• dump command for wallet to dump it (replaced non-functional open
  command, #589)
• support for single-node consensus setup (#595)
• ping/pong P2P messages are now supported with PingInterval and PingTimeout
  configuration options (#430, #610, #627, #639)
• VM now fully supports calculating GAS spent during execution (#424, #648)
• Fixed8 type now supports YAML marshalling (#609)
• RPC invoke* calls can now be GAS-limited with MaxGasInvoke configuration
  option (#609)
• gas limit for free invocation transactions can now be configured with
  FreeGasLimit option which default to 10.0 for mainnet and testnet (#609)
• new compiler interop VerifySignature to verify ECDSA signatures (#617)
• compiler now supports loops with single condition (no init/post, #618)
• memory pool size is now configurable with MemPoolSize option which defaults
  to 50000 for all configurations (#614)
• support for variables in slice literals in the compiler (#619)
• support for map literals in the compiler (#620)
• AppCall interop function (#621)
• string to []byte conversion was implemented in the compiler (#622)
• Docker images now contain a dump of 1600 blocks for single-node setups and
  one can choose which dump to use for restore with ACC environment variable
  (#625)
• switch statement support in the compiler (#626)
• panic support in the compiler (#629)

Behaviour changes:

• NEP2Decrypt function in keys package now returns a pointer to PrivateKey
  rather than a WIF-encoded string (#589)
• DecryptAccount function in wallet package was moved to Decrypt method of
  Account (#589)
• logging was moved from logrus to zap which changed messages format a little
  (#284, #598)
• Block, BlockBase and Header structures were moved into their own block
  package (#597)
• MemPool was moved into its own mempool package (#597)
• Sign method of PrivateKey no longer returns an error (#604)
• wallet is now compatible with C# node wallets (#603)
• consensus service now gets its keys from the wallet file instead of
  plain-text WIF in the configuration (#588)
• image Makefile target was updated to nspccdev repo (#625)
• serializing invalid Transaction structures (that have no Data) is now
  forbidden (#640)
• Item is no longer exposed by the mempool package (#647)

Improvements:

• better testing of keys, wallet, compiler and mempool packages (#589, #568,
  #647)
• smart use of previous proposal for block generation after dBFT's ChangeView
  (#591)
• peer-server interaction refactored (#606)
• peer message queues were introduced with different priorities reducing
  delays in consensus messages delivery and improving unicast communication
  (#590, #615, #639)
• more efficient code generated by the compiler in some cases (#626, #629,
  #637)
• mempool redesign leading to better performance (#647), it also doesn't
  store unverified transactions now

Bugs fixed:

• consensus service was not really requesting transactions from peers when it
  was missing some locally (#602)
• build failing with newer rfc6979 package (#592)
• wrong integer serialization/deserialization in VM leading to
  inconsistencies in state with C# node (#501/#605)
• consensus service was not processing node election results to
  enable/disable dBFT (#603)
• in some cases peers were not unregistered after disconnect (#606)
• different execution results with C# node because of missing invocation fee
  calculations (#607)
• RPC server now properly returns the amount of gas spent during execution
  for invoke* calls (#609)
• FromAddress interop was translated improperly by the compiler (#621)
• compiler emitting wrong integers (#624)
• EOF errors on recovery consensus messages decoding (#632)
• wrong handling of assignments to underscore variable in the compiler (#631)
• wrong answers to getunspents/getaccountstate RPC requests for unknown
  addresses (#633)
• multiple dBFT issues leading to consensus stalls, attempts to add wrong
  block to the chain, message processing using wrong height and other
  problems (#635, #641)
• duplicate connections were not detected before the handshake completion
  which can happen too late (#639)
• attempts to connect to peer that has already connected to node (#639)
• unregistration of connected addresses (#639)
• ArrayReverse function was not copying arrays of size 1 (#644)
• race in transaction verification/addition to the mempool leading to
  potential double spends (#647)
• wrong concurrent attempts to add new block to the chain (#647)
• blocks were not relayed properly by non-consensus nodes (#647)
• mempool memory leak (#647)
• missing reverification after block acceptance for transactions in mempool
  (#647)

Celebration

Version 0.71.0 ends the year 2019 of neo-go development with a solid release
that adds support for pprof, implements all missing interoperability
functions, improves performance and as usual fixes some bugs. This is also the
first release with a test coverage of more than 60% which is a significant
milestone in our trend to improve code quality and testing. Back in August
2019 when NSPCC had started neo-go developement the project only had a
coverage of 45% and even though a lot of code has been added since we're
improving this metrics with every release.

New features:

• pprof support (disabled by default, #536)
• compiler now supports assignments to an element of slice using variable
  index (#564)
• hashed 4-byte IDs support for SYSCALL instruction (#565)
• remainder ('%') operator support in compiler (#563)
• Neo.Witness.GetVerificationScript and Neo.InvocationTransaction.GetScript
  interop functions (#421)
• Neo.Iterator., Neo.Enumerator. and Neo.Storage.Find interops (#422)
• tuple return support in compiler (#562)
• getblocks P2P command implementation (#577)

Behaviour changes:

• db dump command now also writes the block number zero by default to
  comply with ImportBlocks format (#582)
• skip parameter was renamed to start in the db dump command (#582)
• db restore now skips the genesis block in the dump if starting to import
  into the new DB and if this block matches the one generated on blockchain
  init (#582)

Improvements:

• VM optimizations (#558, #559, #565, #572)
• top block caching in core to improve dApps performance (#572)
• transaction's TXType can now be JSON-unmarshalled (#575)
• crypto package no longer exports AES functions (#579)
• merkle tree functions and structures were moved into the hash package
  (#579)
• base58 functionality was moved into its own package from crypto (#579)
• Uint160DecodeAddress and AddressFromUint160 functions were moved out of
  crypto into their own package (#579)
• address package now can be configured to use different prefixes (#579)

Bugs fixed:

• wrong INVERT instruction behaviour for converted values (#561)
• wrong DUP behaviour when the next instruction doesn't convert the value
  (#561)
• OVER and PICK implementations didn't properly duplicate stack items (#561)
• PICKITEM instruction failed to duplicate picked items (#561)
• getblock RPC call was not answering with full hex-encoded block (#575)
• base58.CheckDecode was decoding values with leading zeroes in a wrong way
  (#579)
• decoding wrong public key could succeed (#579)
• consensus payload verification was inconsistent with other verification
  code (#555)
• DB dump was using wrong format in release 0.70.1 (#582)
• DB restorer was not properly counting skipped blocks which could lead to
  bogus error being reported (#582)
• the DB was not closed properly on error during DB restore (#582)
• NPE in consensus (#583)

Centrifugation

Release 0.70.1 brings no new functionality focusing on internal node
improvements instead. Some bugs were fixed, refactoring was done and
performance was improved substantially.

Behaviour changes:

• as with the previous release, this one changes the database format, so you
  need to resynchronize your nodes
• code testing will fail if you're not to checkout submodules (we have one
  with neo-vm tests, #543)

Improvements:

• "inv" command handling was changed to not ask peers of the items we already
  have (#533)
• numerous optimizations across the whole system (#535, #546, #547, #545,
  #549, #550, #553, #554, #556, #557)
• compiler no longer outputs errors by itself, passing them programmatically
  instead via its API (#457)
• VM opcodes were moved into their own package allowing wider reuse (#538)
• compiler package was moved one level up from pkg/vm/compiler to
  pkg/compiler (#538)
• proper script trigger constants were added (#509)
• consensus payloads are now properly signed and this signature is being
  checked (#544)
• Uint160/Uint256 types were made more consistent and having an explicit
  LE/BE suffix for conversion functions (#314)
• a separate layer based on storage.Store with state item-specific functions
  was created (#517, #334)
• ReadBytes/WriteBytes in io package were renamed into
  ReadVarBytes/WriteVarBytes to more accurately describe them and be more
  consistent with C# implementation (#545)
• io package was refactored to add type-specific read/write methods to its
  structures and remove generic (slow) ReadLE/WriteLE (#553, #554)
• a simple tx performance benchmark was added (#551)

Bugs fixed:

• consensus could start and stall with not-yet-connected peers (#532)
• nil pointer dereference in PrepareResponse and PrepareRequest messages
  handling (#532)
• fatal error because of locking problems in mempool (#535)
• missing error handling in compiler emitter functions (#297)
• wallet opening command now hides the password printed into it (#539)
• storage was updated improperly when several transactions in one block were
  touching the same keys, leading to subsequent transactions failures (#542)
• application execution results were not saved in full (#517)
• mempool transaction verification was wrong (#557)

Constellation

This is a long-awaited and exciting release implementing a full Neo
consensus node that you can run your own neo-go private net with! It also
brings with it serious improvements in contract handling, you can now not
only compile, but also deploy and invoke contracts with neo-go.

New features:

• systemd unit file for deployment (#326)
• claim transactions processing was added (#489)
• Consensus payloads decoding/encoding (#431)
• getunspents method is RPC server (#473)
• updated docker-compose environment for privnet setup (#497, #529)
• client-side getunspents RPC method support (#511)
• contract deployment from the CLI (#474)
• enrollment and state transactions processing (#508)
• Neo.Blockchain.GetValidators interop support (#420)
• invokefunction RPC method support in the server (#347)
• testinvokefunction command in the CLI to do test invocations via
  invokefunction RPC method (#521)
• consensus node support (#507, #525)
• server-side invoke RPC method support (#346)
• testinvoke CLI command to invoke contracts via invoke RPC method (#527)
• getheaders P2P message processing (#529)
• relaying was added for transactions coming from P2P network (#529)
• invoke and invokefunction commands to invoke deployed script and send an
  invocation transaction to the network (#531)

Behavior changes:

• db dump/restore format is now compatible with NGD chain dumps (#466)
• smart contracts now have a new configuration format that is used to deploy
  them (#511)
• testinvoke CLI command was renamed to testinvokescript (#521)

Improvements:

• core.Blockchainer interface now has a Close method (#485)
• util.Uint256Size is now public (#490)
• io package now has generic functions for array
  serialization/deserialization (#490)
• util.Uint256 now supports io.Serializable interface (#495)
• smartcontract.ParamType type now supports io.Serializable interface
  (#495)
• vm.ByteArrayItem now uses hex representation when being marshalled into
  JSON (#499)
• io serialization/deserialization for arrays is now restricted in elements
  count (#503, #505)
• core.AccountState now stores all UTXOs for the account (#504)
• interop functions got some testing coverage (#492)
• rpc client now implements CalculateInputs method via getunspents call
  for transaction building (#511)
• transaction.NewInvocationTX now accepts a gas parameter for the
  corresponding transaction field (#511)
• rpc.StackParamType now supports YAML marshaling/unmarshaling
• rpc package now has more fine-grained methods for transaction building
  (#511, #531)
• Blockchain now stores and updates validators list (#508)
• blockchain state management refactored (#508)
• rpc invocation parameter management reworked (#513)
• util test coverage improved (#515)
• invokescript tests were added to the rpc package (#521)
• crypto/keys and crypto/hash packages test coverage improved (#516)

Bugs fixed:

• blockchain not persisting the latest changes on exit (#485)
• db dump/restore commands incorrectly handled skip parameter (#486)
• vm failed to serialize duplicating non-reference elements (#496)
• improper smartcontract notifications handling (#453)
• nondeterministic GetReferences interop behaviour leading to contract
  failures (#454)
• writing message to the peer could be interleaved with other messages
  leading to garbage being sent (#503, #506)
• inability to process block with previously relayed transaction (#511)
• decoding transaction with invalid type didn't return an error (#522)
• attempts to reconnect to the node with the same ID (#507)
• peer disconnects during handshake because of code race (#529)
• useless header requests from peers with low height (#529)
• wrong header hashes initialization from the DB in case there are 2000*N + 1
  blocks in the chain (#529)

Commotion

Release 0.62.0 finishes one very important work some pieces of which were
gradually rolled out in previous releases --- it integrates all neo-vm project
JSON-based tests for NEO 2.0 C# VM and runs them successfully against neo-go
VM. There are also important bug fixes based on mainnet nodes deployment
experience and additional configuration options.

New Features:

• implemented Runtime.Serialize and Runtime.Deserialize syscalls (#419)
• new configuration option -- AttemptConnPeers to set the number of
  connections that the node will try to establish when it goes below the
  MinPeers setting (#478)
• LogPath configuration parameter to write logs into some file and not to
  stdout (#460), not enabled by default
• Address configuration parameter to specify the address to bind to (#460),
  not enabled by default

Behavior changes:

• mainnet configuration now has correct ports specified (#478)
• multiple connections to the same peer are disallowed now (as they are in C#
  node (#478))
• the default MaxPeers setting was increased to 100 for mainnet and testnet
  configurations and limited to 10 for privnet (#478)

Improvements:

• implemented missing VM constraints: stack item number limitation (#462) and
  integer size checks (#484, #373)
• added a framework to run JSON-based neo-vm tests for C# VM and fixed all
  remaining incompabitibilities (#196)
• added wallet unit tests (#475)
• network.Peer's NetAddr method was split into RemoteAddr and PeerAddr (#478)
• MakeDirForFile function was added to the io package (#470)

Bugs fixed:

• RPC service responded with block height to getblockcount request which
  differs from C# interpretation of getblockcount (#471)
• getbestblockhash RPC method response was not adding leading 0x prefix
  to the hash, while C# node does it
• inability to correctly handshake clients on the server side (#458, #480)
• data race in Server structure fields access (#478)
• MaxPeers configuration setting was not working properly (#478)
• useless DB reads (that failed in some cases) on persist attempt that didn't
  persist anything (#481)
• current header height was not stored in the DB when starting a new
  blockchain which lead to node failures on restart (#481)
• crash on node restart if no header hashes were written into the DB (#481)