In order to enable exact fee calculation for transactions that spend
P2PK outputs in the MiniWallet, we enforce the created signatures to
have a fixed length (>49.89% probability) by default. With that it is
easier to check the created transactions vsize and avoid flaky tests
that would appear whenever the signatures R- or S-values are smaller
(due to leading zero bytes).
Note that to get the total scriptSig size one has to add another
2 bytes, as there is also the OP_PUSHx instruction on the front and
the sighash type byte on the back, leading to a final scriptSig size
of 73 bytes.
2eb0eeda39cab997f9a5f817f7c12e7fffeaf35a validation: document lack of inherited signaling in RBF policy (Antoine Riard)
906b6d9da6a6b2e6a5f1d9046b3b9c2c7e490c99 test: Extend feature_rbf.py with no inherited signaling (Antoine Riard)
Pull request description:
Contrary to BIP125 or other full-node implementation (e.g btcd), Bitcoin Core's mempool policy doesn't implement inherited signaling.
This PR documents our mempool behavior on this and add a test demonstrating the case.
ACKs for top commit:
jonatack:
ACK 2eb0eeda39cab997f9a5f817f7c12e7fffeaf35a
benthecarman:
ACK 2eb0eeda39cab997f9a5f817f7c12e7fffeaf35a
Tree-SHA512: d41453d3b49bae3c1eb532a968f43bc047084913bd285929d4d9cba142777ff2be38163d912e28dfc635f4ecf446de68effad799c6e71be52f81e83410c712fb
7a681d61b0d98a310fbb1b8e095ab8fbc5d5741c Add sync_blocks in wallet_orphanedreward.py. (Daniel Kraft)
Pull request description:
Add an explicit `sync_blocks` call in `wallet_orphanedreward.py`, which was missing and could lead to intermittent failures of the test due to race conditions.
This will presumably fix#22181.
ACKs for top commit:
MarcoFalke:
review ACK 7a681d61b0d98a310fbb1b8e095ab8fbc5d5741c
Tree-SHA512: bb226c31bf3f2e7c52beb829d7b67496e5b38781245db5f9184e3f28c93ac3aa4d21fcf5bf3055e79d384cfd0ed916e79dccb3d77486e86fe1fedb5e35f894ad
Add an explicit sync_blocks call in wallet_orphanedreward.py, which was
missing and could lead to intermittent failures of the test due to
race conditions.
This will presumably fix https://github.com/bitcoin/bitcoin/issues/22181.
fa13f34bf35129b38af699a0faf32c39d2ba8576 fuzz: Increase branch coverage of the float fuzz target (MarcoFalke)
fad0c58c3ecdf2a2a602ff39c9fd9dda7f8747d9 fuzz: Remove confusing return keyword from CallOneOf (MarcoFalke)
Pull request description:
Currently the branch coverage for the float fuzz target is only 50% : https://marcofalke.github.io/btc_cov/fuzz.coverage/src/test/fuzz/float.cpp.gcov.html
This is caused by the Fuzzed Data Provider only picking "nice" floats.
ACKs for top commit:
practicalswift:
cr ACK fa13f34bf35129b38af699a0faf32c39d2ba8576: patch looks correct
Tree-SHA512: 326822515e9a1c77647d41eab9a96185a3b320914d9264730fa72ffb76c2bf3dc5bf72cf6cd9beef14f4f032358d76a976860bf3e2418ae61943cf926c0ea086
ecbd91153875c8cdd5b92b840afc116f65e457fb qt: Handle peer addition/removal in a right way (Hennadii Stepanov)
1b66f6e556631a1a2d89aefba70a79894bd14fcd qt: Drop PeerTablePriv class (Hennadii Stepanov)
efb7e5aa962d4a4047061996bbb50b6da4592cbc qt, refactor: Use default arguments for overridden functions (Hennadii Stepanov)
Pull request description:
This PR makes `PeerTableModel` handle a peer addition/removal in a right way. See:
- https://doc.qt.io/qt-5/model-view-programming.html#inserting-and-removing-rows
- https://doc.qt.io/qt-5/model-view-programming.html#resizable-modelsFixes#160.
Fixes#191.
ACKs for top commit:
jarolrod:
re-ACK ecbd911
promag:
reACK ecbd91153875c8cdd5b92b840afc116f65e457fb just improvements to the comment since last review.
Tree-SHA512: 074935d67f78561724218e8b33822e2de16749f873c29054926b720ffcd642f08249a222b563983cf65a9b716290aa14e2372c47fc04e5f401f759db25ca710f
5c7ee1b2da6bf783d27034fca9dfd3a64ed525cb libsecp256k1 no longer has --with-bignum= configure option (Pieter Wuille)
bdca9bcb6c9379707d09c63f02326884befbefb2 Squashed 'src/secp256k1/' changes from 3967d96bf1..efad3506a8 (Pieter Wuille)
cabb5661234f8d832dbc3b65bf80b0acc02db0a0 Disable certain false positive warnings for libsecp256k1 msvc build (Pieter Wuille)
Pull request description:
This updates our src/secp256k1 subtree to the latest upstream master. The changes include:
* The introduction of safegcd-based modular inverses, reducing ECDSA signing time by 25%-30% and ECDSA verification time by 15%-17%.
* [Original paper](https://gcd.cr.yp.to/papers.html) by Daniel J. Bernstein and Bo-Yin Yang
* [Implementation](https://github.com/bitcoin-core/secp256k1/pull/767) by Peter Dettman; [final](https://github.com/bitcoin-core/secp256k1/pull/831) version
* [Explanation](https://github.com/bitcoin-core/secp256k1/blob/master/doc/safegcd_implementation.md) of the algorithm using Python snippets
* [Analysis](https://github.com/sipa/safegcd-bounds) of the maximum number of iterations the algorithm needs
* [Formal proof in Coq](https://medium.com/blockstream/a-formal-proof-of-safegcd-bounds-695e1735a348) by Russell O'Connor, for a high-level equivalent algorithm
* Removal of libgmp as an (optional) dependency (which wasn't used in the Bitcoin Core build)
* CI changes (Travis -> Cirrus)
* Build system improvements
ACKs for top commit:
laanwj:
Tested ACK 5c7ee1b2da6bf783d27034fca9dfd3a64ed525cb
Tree-SHA512: ad8ac3746264d279556a4aa7efdde3733e114fdba8856dd53218588521f04d83950366f5c1ea8fd56329b4c7fe08eedf8e206f8f26dbe3f0f81852e138655431
faa94961d6e38392ba068381726ed4e033367b03 test: Add temporary logging to debug #20975 (MarcoFalke)
Pull request description:
to be reverted after a fix
ACKs for top commit:
laanwj:
Code review ACK faa94961d6
Tree-SHA512: 1f3103fcf4cad0af54e26c4d257bd824b128b5f2d2b81c302e861a829fd55d6a099fa476b79b30a71fe98975ae604b9e3ff31fd48a51d442389a9bd515e60ba0
The Tor v2 addresses, left over from when Tor v2 was supported will be
unserialized as a dummy, invalid `::` (all zeros) IPv6 address. Remove
them so that they do not take up space in addrman.
The return type is already enforced to be void by the
ternary operator:
./test/fuzz/util.h:47:25: error: right operand to ? is void, but left operand is of type *OTHER_TYPE*
((i++ == call_index ? callables() : void()), ...);
^ ~~~~~~~~~~~ ~~~~~~
3737d35fee283968f12e0772aa27aee4981fce41 fuzz: Terminate immediately if a fuzzing harness ever tries to perform a DNS lookup (belts and suspenders) (practicalswift)
Pull request description:
Terminate immediately if a fuzzing harness tries to perform a DNS lookup (belt and suspenders).
Obviously this _should_ never happen, but if it _does_ happen we want immediate termination instead of a DNS lookup :)
ACKs for top commit:
MarcoFalke:
review ACK 3737d35fee283968f12e0772aa27aee4981fce41
Tree-SHA512: 51cd2d32def7f9f052e02f99c354656af1f807cc9fdf592ab765e620bfe660f1ed26e0484763f94aba650424b44959eafaf352bfd0f81aa273e350510e97356e
68ace23fa3bc01baa734ddf2c0963acae1c75ed1 test: convert docs into type annotations in test_framework/test_node.py (fanquake)
8bfcba36db974326d258c610456bd55cf5818b1e test: convert docs into type annotations in test_framework/wallet.py (fanquake)
b043ca8e8b65199061ebe4bbed2200504dfc6ce9 test: convert docs into type annotations in test_framework/util.py (fanquake)
Pull request description:
Rather than having function types exist as documentation, make them type annotations, which enables more `mypy` checking.
ACKs for top commit:
instagibbs:
utACK 68ace23fa3
Tree-SHA512: b705f26b48baabde07b9b2c0a8d547b4dcca291b16eaf5ac70462bb3a1f9e9c2783d93a9d4290889d0cbb3f7db3671446754411a1f498b265d336f6ff33478df
c274574458e5921be4d1f3e86e6bba72a7cd3e65 p2p, rpc, fuzz: various tiny follow-ups (Jon Atack)
Pull request description:
- p2p: pass `Span` by value per https://github.com/bitcoin/bitcoin/pull/22143#issuecomment-853953438 as a follow-up to 8be56f0f8ecc54744
- rpc: remove duplicate `CAddress` constructor per https://github.com/bitcoin/bitcoin/pull/22043#discussion_r638535703
- fuzz: rename 3 fuzz targets changed in eba9a94b9f56be2fda623e77f19b960425ea1eb5 back to their original names per https://github.com/bitcoin-core/qa-assets/pull/63#issuecomment-855281865
ACKs for top commit:
MarcoFalke:
cr ACK c274574458e5921be4d1f3e86e6bba72a7cd3e65
practicalswift:
cr ACK c274574458e5921be4d1f3e86e6bba72a7cd3e65: patch looks correct
jarolrod:
ACK c274574458e5921be4d1f3e86e6bba72a7cd3e65
Tree-SHA512: 3672b210d30b3a91f3a6455005e4d3cb1f89621820c417c645d24b06e53459440122a1f75758e0e04c3d04eff9d6f88ef62865216aa3e42301c6df783f7c0b4a
62cb8d98d27e7f316f01f177f35ad0ed6f8cd9ce qt: Drop BitcoinGUI* WalletFrame data member (Hennadii Stepanov)
f73e5c972ab096e0f80cb9e753fa221d17313358 qt: Move CreateWalletActivity connection from WalletFrame to BitcoinGUI (Hennadii Stepanov)
20e2e24e90d782219e853ef0676ac66dc6a9de6a qt: Move WalletView connections from WalletFrame to BitcoinGUI (Hennadii Stepanov)
Pull request description:
This PR:
- implements an idea from https://github.com/bitcoin/bitcoin/pull/17937#issuecomment-575991765
- simplifies `WalletFrame` class interface
- as a side effect, removes `bitcoingui` -> `walletframe` -> `bitcoingui` circular dependency
- is an alternative to https://github.com/bitcoin/bitcoin/pull/17500
ACKs for top commit:
promag:
Tested ACK 62cb8d98d27e7f316f01f177f35ad0ed6f8cd9ce on macos 11.2.3 with depends build.
jarolrod:
ACK 62cb8d98d27e7f316f01f177f35ad0ed6f8cd9ce
Tree-SHA512: 633b526a8499ba9ab4b16928daf4de4f6d610284bb9fa51891cad35300a03bde740df3466a71b46e87a62121330fcc9e606eac7666ea5e45fa6d5785b60dcbbd
fb1b1e0f3eae32b087347889ed7502b7f2c48549 qt: Save/restore column sizes of the tables in the Peers tab (Hennadii Stepanov)
Pull request description:
ACKs for top commit:
jonatack:
ACK fb1b1e0f3eae32b087347889ed7502b7f2c48549 code review, debug-built and tested
jarolrod:
ACK fb1b1e0f3eae32b087347889ed7502b7f2c48549
Tree-SHA512: f93495ecd13e4202aba61b407fffbeec855f5b0c1cc027197c78edddd7d11c87ebdb0fcb1daac242f0407323b31f4e7e0313bd76113a5241e4c868a8829af20a
8b419b5163d41c0caef7b9fa6d3008b73917e8ee qt: make console buttons look clickable (Jarol Rodriguez)
Pull request description:
On master, for macOS, the console buttons' hitboxes are quite small. This makes clicking on the button with your mouse a little more tedious than it should be. The Issue is related to recent versions of Qt (>5.9.8) not playing so nice on macOS when there are "incorrect" `width` and `height` values set for a `QPushButton` (here is another example: https://github.com/bitcoin-core/gui/pull/319#pullrequestreview-652907740).
This fixes this small hitbox issue by converting the buttons from `QPushButton` to `QToolButton`, which in turn makes the buttons look explicitly clickable. This approach was chosen as it helps us avoid having to play around with `width` and `height` values until we find values that play nice with macOS and look good on Linux & Windows. Also, `QToolButton` is an appropriate class for these buttons.
Per [Qt Docs](https://doc.qt.io/qt-5/qtoolbutton.html#details):
> A tool button is a special button that provides quick-access to specific commands or options. As opposed to a normal command button, a tool button usually doesn't show a text label, but shows an icon instead.
Since we are changing the type of the buttons, we need to change the respective actions connection logic in `rpcconsole`. Instead of plugging in `QToolButton`, we abstract it to the base class: `QAbstractButton`.
per [Qt Dev Notes](https://github.com/bitcoin-core/bitcoin-devwiki/wiki/Developer-Notes-for-Qt-Code#inherited-signals-and-slot)
> Use base class functions as this makes the code more general, e.g., use QAbstractButton::clicked instead of QPushButton::clicked.
While here, we also update the size of the icons to `22x22` to be consistent with other tool buttons.
**macOS: Master vs PR:**
| Master | PR |
| ----------- | ----------- |
|  |  |
**Linux: Master vs PR:**
| Master | PR |
| ----------- | ----------- |
|  |  |
ACKs for top commit:
hebasto:
ACK 8b419b5163d41c0caef7b9fa6d3008b73917e8ee, tested on Linux Mint 20.1 (Qt 5.12.8).
promag:
Tested ACK 8b419b5163d41c0caef7b9fa6d3008b73917e8ee on macOS Big Sur M1, this drops only relevant usages to `flat` buttons.
Tree-SHA512: 3f3cdcbe83398136a1d1ee8fc2835be8681f2ed39e79db1e939cab6a00a779f528343d54992807a845cc84d9ef13591affb7a6dbca9e5753a2b8665b0af4d611
69b8b5d72c47d42a9e69e6666af89606057be15b qt: Align numbers in the "Peer Id" column to the right (Hennadii Stepanov)
Pull request description:
On master (6b49d88a5dda97fdbabe363fd7d3c4f1ce29082a):

With this PR:

ACKs for top commit:
jarolrod:
ACK 69b8b5d72c47d42a9e69e6666af89606057be15b
jonatack:
ACK 69b8b5d72c47d42a9e69e6666af89606057be15b happy to re-ack with more separation or center-aligned
kristapsk:
ACK 69b8b5d72c47d42a9e69e6666af89606057be15b
Tree-SHA512: 3279522745a0fe6db1ec9be723a2640a37983947ed1af4aad56f22ce4780cc943a25b2d774529a9eeb3b00309f0204cfbc3f38b7db2c52865d05bf6a7c87e747
fa2b6c62cd9a43d5896bb4b06a3ae64b7199843f test: Remove unused node from feature_nulldummy (MarcoFalke)
Pull request description:
This is confusing and might even slow down the test.
This reverts a change that was added a year ago in d438d60 and then the need for it was removed by 95d5d5e six months ago.
Top commit has no ACKs.
Tree-SHA512: 9a86792e9a634cf7bbd4e7a21b1acdfc3baba1b1962fe2b9b73848436d10351d2326dca01313c097ba2342dde7207add73e731d053c0bfa888a5d8f2b233a7cf
ca3a77068b8c9c6107d078ea083f4ab7c0010548 test: Fix p2p_leak.py intermittent failure by lowering timeout (Martin Zumsande)
Pull request description:
Fixes#22085
Root cause: There was just 1 second between the wait (5 seconds) and the `-peertimeout=4`.
Since `ShouldRunInactivityChecks` in `net.cpp` measures the timeout in seconds, its result can only change once per second, even though it is called more often.
So in situations when the connection is established early in a given second like [here](https://bitcoinbuilds.org/index.php?ansilog=d7b3e075-683a-45cc-94d4-9645fc17e0b6.log#l3117) (2021-05-27T12:28:04.**001**913Z ), the 1 second leeway was not be sufficient, leading to the intermittent failures.
Fix this by lowering the timeout by one second.
ACKs for top commit:
MarcoFalke:
re-ACK ca3a77068b8c9c6107d078ea083f4ab7c0010548
Tree-SHA512: e7e22356d276c65a5b4f0a1b7ee5a9ad07d27691220746c7d02af3fad22cab1d53fd0ef59a938167ec80e4571c96649132d6922ad10667fc91baa47892f27a3e
Reduce the condition `IsRFC4193() && !IsTor()` to `IsRFC4193()`. We know
that if `IsRFC4193()` is `true` then, for sure, the address is not Tor,
so `!IsTor()` is also `true`.
e4356f6a6c18e5027a064a4d3a5deda27985f584 Testcase for wallet issue with orphaned rewards. (Daniel Kraft)
Pull request description:
This adds a new test case demonstrating the wallet issue when block rewards are orphaned (#14148).
ACKs for top commit:
LarryRuane:
ACK e4356f6a6c18e5027a064a4d3a5deda27985f584
leonardojobim:
reACK e4356f6a6c .
Tree-SHA512: e9a2310ee1b3d52cfa302f431ed3d272bbc1b9195439ff318d9eb1006c0b28968dbe840e1600b6ff185e5d7ea57e4dcc837cef16051b5537445e10bc363b8c22
3d552b0d788a7d3102396b32d0de08e57cbfd297 [doc] explain why CheckBlock() is called before AcceptBlock() (Sjors Provoost)
Pull request description:
Based on https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2019-February/016697.html and its PDF attachment.
ACKs for top commit:
MarcoFalke:
cr ACK 3d552b0d788a7d3102396b32d0de08e57cbfd297
Tree-SHA512: d1ef39855317853e0e7e051ec6015054d0d227fcdf20281c2c1921056537f1f79044aa1bdd35f46475edd17596fbcae79aeb338c4865b1269a01b158f6cb2ac4
If all our high-bandwidth compact block serving peers (BIP 152) stall block
download, then we can be denied a block for (potentially) a long time. As
inbound connections are much more likely to be adversarial than outbound
connections, mitigate this risk by never removing our last outbound HB peer if
it would be replaced by an inbound.
2667366aaa69447a9de4d819669d254a5ebd4d4b tests: check derivation of P2TR (Pieter Wuille)
7cedafc5412857404e9a6c3450b100cb8ee4081a Add tr() descriptor (derivation only, no signing) (Pieter Wuille)
90fcac365e1616779b40a69736428435df75fdf2 Add TaprootBuilder class (Pieter Wuille)
5f6cc8daa83700d1c949d968a5cf0d935be337b7 Add XOnlyPubKey::CreateTapTweak (Pieter Wuille)
2fbfb1becb3c0c109cd7c30b245b51da22039932 Make consensus checking of tweaks in pubkey.* Taproot-specific (Pieter Wuille)
a4bf84039c00b196b87f969acf6369d72c56ab46 Separate WitnessV1Taproot variant in CTxDestination (Pieter Wuille)
41839bdb89b3777ece2318877b9c7921ecca2472 Avoid dependence on CTxDestination index order (Pieter Wuille)
31df02a07091dbd5e0b315c8e5695e808f3a5505 Change Solver() output for WITNESS_V1_TAPROOT (Pieter Wuille)
4b1cc08f9f94a1e6e1ecba6b97f99b73fb513872 Make XOnlyPubKey act like byte container (Pieter Wuille)
Pull request description:
This is a subset of #21365, to aide review.
This adds support `tr(KEY)` or `tr(KEY,SCRIPT)` or `tr(KEY,{{S1,{{S2,S3},...}},...})` descriptors, describing Taproot outputs with specified internal key, and optionally any number of scripts, in nested groups of 2 inside `{`/`}` if there are more than one. While it permits importing `tr(KEY)`, anything beyond that is just laying foundations for more features later.
Missing:
* Signing support (see #21365)
* Support for more interesting scripts inside the tree (only `pk(KEY)` is supported for now). In particular, a multisig policy based on the new `OP_CHECKSIGADD` opcode would be very useful.
* Inferring `tr()` descriptors from outputs (given sufficient information).
* `getaddressinfo` support.
* MuSig support. Standardizing that is still an ongoing effort, and is generally kind of useless without corresponding PSBT support.
* Convenient ways of constructing descriptors without spendable internal key (especially ones that arent't trivially recognizable as such).
ACKs for top commit:
Sjors:
utACK 2667366 (based on https://github.com/bitcoin/bitcoin/pull/21365#issuecomment-846945215 review, plus the new functional test)
achow101:
Code Review ACK 2667366aaa69447a9de4d819669d254a5ebd4d4b
lsilva01:
Tested ACK 2667366aaa
meshcollider:
utACK 2667366aaa69447a9de4d819669d254a5ebd4d4b
Tree-SHA512: 61046fef22c561228338cb178422f0b782ef6587ec8208d3ce2bd07afcff29a664b54b35c6b01226eb70b6540b43f6dd245043d09aa6cb6db1381b6042667e75
5d82a57db4f67506a4e80d186ba76f3a8665e147 contrib: remove torv2 seed nodes (Jon Atack)
5f7e086dac78c9070f8292a1757d7e77e110f772 contrib: update generate-seeds.py to ignore torv2 addresses (Jon Atack)
8be56f0f8ecc54744d572e5678a3089665587b98 p2p, refactor: extract OnionToString() from CNetAddr::ToStringIp() (Jon Atack)
5f9d3c09b4c9cd026cdc7c3a81f91632280917b7 p2p: remove torv2 from CNetAddr::ToStringIP() (Jon Atack)
3d390421440f1cae9a9f2b089561c183ecd1b073 p2p: remove torv2 in SetIP() and ADDR_TORV2_SIZE constant (Jon Atack)
cff5ec477a388ae9aa9fd9ef6a7dad1f678e7d23 p2p: remove pre-addrv2 onions from SerializeV1Array() (Jon Atack)
4192a74413907717d6173e393724b931f2225dd9 p2p: ignore torv2-in-ipv6 addresses in SetLegacyIPv6() (Jon Atack)
1d631e956fffbbc7891ed40be4fd39aeff036c52 p2p: remove BIP155Network::TORV2 from GetBIP155Network() (Jon Atack)
7d1769bc450a98c093a066d6daed84337040dbfb p2p: remove torv2 from SetNetFromBIP155Network() (Jon Atack)
eba9a94b9f56be2fda623e77f19b960425ea1eb5 fuzz: rename CNetAddr/CService deserialize targets (Jon Atack)
c56a1c9b182815018b8bd3d8e6b8c2cb27859607 p2p: drop onions from IsAddrV1Compatible(), no longer relay torv2 (Jon Atack)
f8e94002fcfdc7890d38c23488b1f3a662e97bc4 p2p: remove torv2/ADDR_TORV2_SIZE from SetTor() (Jon Atack)
0f1c58ae87d6a3fe81816500e7b8275420d151d0 test: update feature_proxy to torv3 (Jon Atack)
Pull request description:

This patch removes support in Bitcoin Core for Tor v2 onions, which are already removed from the release of Tor 0.4.6.
- no longer serialize/deserialize and relay Tor v2 addresses
- ignore incoming Tor v2 addresses
- remove Tor v2 addresses from the addrman and peers.dat on node launch
- update generate-seeds.py to ignore Tor v2 addresses
- remove Tor v2 hard-coded seeds
Tested with tor-0.4.6.1-alpha (no v2 support) and 0.4.5.7 (v2 support). With the latest Tor (no v2 support), this removes all the warnings like those reported with current master in https://github.com/bitcoin/bitcoin/issues/21351
```
<bitcoind debug log>
Socks5() connect to […].onion:8333 failed: general failure
<tor log>
Invalid hostname [scrubbed]; rejecting
```
and the addrman no longer has Tor v2 addresses on launching bitcoind.
```rake
$ ./src/bitcoin-cli -addrinfo
{
"addresses_known": {
"ipv4": 44483,
"ipv6": 8467,
"torv2": 0,
"torv3": 2296,
"i2p": 6,
"total": 55252
}
}
```
After recompiling back to current master and restarting with either of the two Tor versions (0.4.5.7 or 0.4.6.1), -addrinfo initially returns 0 Tor v2 addresses and then begins finding them again.
Ran nodes on this patch over the past week on mainnet/testnet/signet/regtest after building with DEBUG_ADDRMAN.
Verified that this patch bootstraps an onlynet=onion node from the Tor v3 hardcoded fixed seeds on mainnet and testnet and connects to blocks and v3 onion peers: `rm ~/.bitcoin/testnet3/peers.dat ; ./src/bitcoind -testnet -dnsseed=0 -onlynet=onion`

Tested using `addnode`, `getaddednodeinfo`,`addpeeraddress`, `disconnectnode` and `-addrinfo` that a currently valid, connectable Tor v2 peer can no longer be added:

Thanks to Vasil Dimov, Carl Dong, and Wladimir J. van der Laan for their work on BIP155 and Tor v3 that got us here.
ACKs for top commit:
laanwj:
Code review ACK 5d82a57db4f67506a4e80d186ba76f3a8665e147
Tree-SHA512: 590ff3d2f6ef682608596facb4b01f44fef69716d2ab3552ae1655aa225f4bf104f9ee08d6769abb9982a8031de93340df553279ce1f5023771f9f2b651178bb