4e28753f60613ecd35cdef87bef5f99c302c3fbd feestimator: encapsulate estimation file logic (Antoine Poinsot)
e8ea6ad9c16997bdc7e22a20eca16e234290b7ff init: don't create a CBlockPolicyEstimator if we don't relay transactions (Antoine Poinsot)
86ff2cf202bfb9d9b50800b8ffe3fead3f77f5fa Remove the remaining fee estimation globals (Antoine Poinsot)
03bfeee957ab7e3b6aece82b9561774648094f54 interface: remove unused estimateSmartFee method from node (Antoine Poinsot)
Pull request description:
If the `blocksonly` mode is turned on after running with transaction
relay enabled for a while, the fee estimation will serve outdated data
to both the internal wallet and to external applications that might be
feerate-sensitive and make use of `estimatesmartfee` (for example a
Lightning Network node).
This has already caused issues (for example https://github.com/bitcoin/bitcoin/issues/16840 (C-lightning), or https://github.com/lightningnetwork/lnd/issues/2562 (LND)) and it seems prudent to fail rather than to give inaccurate values.
This fixes#16840, and closes#16890 which tried to fix the symptoms (RPC) but not the cause as mentioned by sdaftuar :
> If this is a substantial problem, then I would think we should take action to protect our own wallet users as well (rather than hide the results of what our fee estimation would do!).
ACKs for top commit:
MarcoFalke:
re-ACK 4e28753f60 👋
jnewbery:
utACK 4e28753f60613ecd35cdef87bef5f99c302c3fbd
Tree-SHA512: c869cf03b86d8194002970bbc84662dae76874967949b9be0d9a4511a1eabcb1627c38aca3154da9dcece1a4c49ec02bd4f9fcca2ec310986e07904559e63ba8
fa6af312277bb1b7e57d9b764d411c5b0873829f test: Document why syncwithvalidationinterfacequeue is needed in tests (MarcoFalke)
fa135a13b8ddaa117bd090ec43a3eab3a95755c1 Revert "test: Add missing sync_all to wallet_balance test" (MarcoFalke)
Pull request description:
syncwithvalidationinterfacequeue is a hidden test-only RPC, so it should not be used when it is not needed. Thus, either remove it or explain why it is needed.
ACKs for top commit:
fjahr:
Code review ACK fa6af312277bb1b7e57d9b764d411c5b0873829f
Tree-SHA512: de30db4ab521184091ee5beeab02989138cf7cf05088f766a2fb106151b239310b63d5380cb79e2a072f72c5ae9513aecae8eb9c1c7be713771585c3cb04d63a
Tests that a fully signed transaction given to
signrawtransactionwithwallet is both unchanged and marked as complete.
This tests for a regression in 0.20 where the transaction would not be
marked as complete.
This moves the CBlockPolicyEstimator to the NodeContext, which get rids
of two globals and allows us to conditionally create the
CBlockPolicyEstimator (and to remove a circular dep).
Signed-off-by: Antoine Poinsot <darosior@protonmail.com>
fad7be584ffaf8099cc099d9378ba831c9483260 test: Fix intermittent p2p_finerprint issue (MarcoFalke)
Pull request description:
A single sync_with_ping can't be used to drop a block announcement, as the block might be sent *after* the ping has been responded to.
Fix that by waiting for the block.
ACKs for top commit:
theStack:
ACK fad7be584ffaf8099cc099d9378ba831c9483260
Tree-SHA512: d43ba9d07273486858f65a26326cc6637ef743bf7b400e5048ba7eac266fb1893283e6503dd49f179caa1abab2977315fb70ba9fba34be9a817a74259d8e4034
1e62350ca20898189904a88dfef9ea11ddcd8626 refactor: Improve use of explicit keyword (Fabian Jahr)
c502a6dbfb854ca827a5a3925394f9e09d29b898 lint: Use c++17 std in cppcheck linter (Fabian Jahr)
Pull request description:
I found the `extended-lint-cppcheck` linter still uses `std=c++11` when reviewing #20471. The only difference in the output after this change is one line is missing:
```
src/script/descriptor.cpp:159:5: warning: Struct 'PubkeyProvider' has a constructor with 1 argument that is not explicit. [noExplicitConstructor]
```
After some digging, I am still not sure why this one is ignored with c++17 when 40 other`noExplicitConstructor` warnings were still appearing.
In the second commit, I fix these warnings, adding `explicit` where appropriate and adding fixes to ignore otherwise.
ACKs for top commit:
practicalswift:
cr ACK 1e62350ca20898189904a88dfef9ea11ddcd8626: patch looks correct!
MarcoFalke:
review ACK 1e62350ca20898189904a88dfef9ea11ddcd8626
Tree-SHA512: dff7b324429a57160e217cf38d9ddbb6e70c6cb3d3e3e0bd4013d88e07afc2292c3df94d0acf7122e9d486322821682ecf15c8f2724a78667764c05d47f89a12
053b4fbad8729308774d5e7b53f53c12627fa88b doc: Release note regarding -rpcauth validation (João Barbosa)
46001323b1f4a57d8d6805f1bc39a5b8d401f0c5 rpc: Validate -rpcauth arguments (João Barbosa)
d37c813a43166f559a4e2d1c22e7243f70301291 rpc: Refactor to process -rpcauth once (João Barbosa)
Pull request description:
Invalid `-rpcauth` arguments are currently silently ignored. This make server initialization fail if any `-rpcauth` is invalid.
ACKs for top commit:
MarcoFalke:
review ACK 053b4fbad8729308774d5e7b53f53c12627fa88b
jonatack:
ACK 053b4fbad8729308774d5e7b53f53c12627fa88b
ryanofsky:
Code review ACK 053b4fbad8729308774d5e7b53f53c12627fa88b. Only changes since last review are moving a variable declaration and adding a comment, release notes, and a `const`.
Tree-SHA512: c99923d4a121f0c9f882b07f5402ea53e9b2d9455ad34468a094ffab1d64df26c82e1279734c0d42bc2e113eae7b581fbc3be52f3ed4a2d7450d11793afcf406
fada2dfcac1c4b47ee76b877d91d515cf1d36410 test: Fix wallet_multiwallet issue on windows (MarcoFalke)
Pull request description:
The error message on windows:
> 2020-11-30T18:10:47.536032Z ListWalletDir: Error scanning C:\Users\user\AppData\Local\Temp\test_runner_₿_🏃_20201130_181042\wallet_multiwallet_0\node0\regtest\wallets\self_walletdat_symlink: boost::filesystem::status: The name of the file cannot be resolved by the system: "C:\Users\user\AppData\Local\Temp\test_runner_₿_🏃_20201130_181042\wallet_multiwallet_0\node0\regtest\wallets\self_walletdat_symlink\wallet.dat"
ACKs for top commit:
promag:
Code review ACK fada2dfcac1c4b47ee76b877d91d515cf1d36410. Although it could ignore (don't log) directories that lead to no permission error.
fanquake:
ACK fada2dfcac1c4b47ee76b877d91d515cf1d36410
Tree-SHA512: b475162cc3cd1574209d916605b229a79c8089714295f5e16569b71f958f0007d54dc76833938492d931387784588b11b73e3ef00f963540af42c079417f8d72
3ebde2143aa98af213872b98b474d904e55056f7 [test] Fix wait condition in disconnect_p2ps (Amiti Uttarwar)
Pull request description:
#19315 currently has a [test failure](https://cirrus-ci.com/task/4545582645641216) because of a race. `disconnect_p2ps` is intended to have a `wait_until` clause that prevents this race, but the conditional doesn't match since its comparing two different object types. `MY_SUBVERSION` is defined in messages.py as a byte string, but is compared to the value returned by the RPC. This PR simply converts types to ensure they match, which should prevent the race from occurring.
HUGE PROPS TO jnewbery for discovering the issue 🔎
ACKs for top commit:
jnewbery:
ACK 3ebde2143aa98af213872b98b474d904e55056f7
glozow:
Code review ACK 3ebde2143a
Tree-SHA512: ca096b80a3e4d757a645f38846d6dc89d6a3d35c3435513a72d278e305faddd4aff9e75a767941b51b2abbf59c82679bac1e9a0140d6f285efe3053e51bcc2a8
89bdad5b25ae4ac03a486f729a5b58ae6f21946d RPC/Wallet: unloadwallet: Allow specifying wallet_name param matching RPC endpoint (Luke Dashjr)
Pull request description:
Allow specifying the `wallet_name` param to `unloadwallet` on RPC wallet endpoints, so long as it matches the endpoint wallet.
ACKs for top commit:
jonatack:
ACK 89bdad5b25ae4ac03a486f729a5b58ae6f21946d
MarcoFalke:
review ACK 89bdad5b25ae4ac03a486f729a5b58ae6f21946d
Tree-SHA512: efb399c33f7b5596870a26a8680f453ca47aa7a6db4e550f9435d13044f1c4bad0ae11e8f0205213409d08b75c4188c3be782e54aafab1f65b97eb8cf5c252a9
MY_SUBVERSION is defined in messages.py as a byte string, but here we were
comparing this value to the value returned by the RPC. Convert to ensure the
types match.
3eb6f8b2e61c24a22ea9396d86672307845f35eb wallet (not for backport): improve upgradewallet error messages (Jon Atack)
ca8cd893bb56bf5d455154b0498b1f58f77d20ed wallet: fix and improve upgradewallet error responses (Jon Atack)
99d56e357159c7154f69f28cb5587c5ca20d6594 wallet: fix and improve upgradewallet result responses (Jon Atack)
2498b04ce88696a3216fc38b7d393906b733e8b1 Don't upgrade to HD split if it is already supported (Andrew Chow)
c46c18b788cb0862aafbb116fd37936cbed6a431 wallet: refactor GetClosestWalletFeature() (Jon Atack)
Pull request description:
This follows up on #18836 and #20282 to fix and improve the as-yet unreleased `upgradewallet` feature and also implement review follow-up in https://github.com/bitcoin/bitcoin/pull/18836#discussion_r519328607.
This PR fixes 4 upgradewallet issues:
- this bug: https://github.com/bitcoin/bitcoin/pull/20403#discussion_r526063920
- it returns nothing in the absence of an RPC error, which isn't reassuring for users
- it returns the same thing both in the case of a successful upgrade and when no upgrade took place
- the error message object is currently dead code
This PR fixes the above and provides:
...user feedback to not silently return without upgrading
```
{
"wallet_name": "disable private keys",
"previous_version": 169900,
"current_version": 169900,
"result": "Already at latest version. Wallet version unchanged."
}
```
...better feedback after successfully upgrading
```
{
"wallet_name": "watch-only",
"previous_version": 159900,
"current_version": 169900,
"result": "Wallet upgraded successfully from version 159900 to version 169900."
}
```
...helpful error responses
```
{
"wallet_name": "blank",
"previous_version": 169900,
"current_version": 169900,
"error": "Cannot downgrade wallet from version 169900 to version 159900. Wallet version unchanged."
}
{
"wallet_name": "blank",
"previous_version": 130000,
"current_version": 130000,
"error": "Cannot upgrade a non HD split wallet from version 130000 to version 169899 without upgrading to support pre-split keypool. Please use version 169900 or no version specified."
}
```
updated help:
```
upgradewallet ( version )
Upgrade the wallet. Upgrades to the latest version if no version number is specified.
New keys may be generated and a new wallet backup will need to be made.
Arguments:
1. version (numeric, optional, default=169900) The version number to upgrade to. Default is the latest wallet version.
Result:
{ (json object)
"wallet_name" : "str", (string) Name of wallet this operation was performed on
"previous_version" : n, (numeric) Version of wallet before this operation
"current_version" : n, (numeric) Version of wallet after this operation
"result" : "str", (string, optional) Description of result, if no error
"error" : "str" (string, optional) Error message (if there is one)
}
```
ACKs for top commit:
achow101:
ACK 3eb6f8b
MarcoFalke:
review ACK 3eb6f8b2e61c24a22ea9396d86672307845f35eb 🛡
Tree-SHA512: b767314069e26b5933b123acfea6aa40708507f504bdb22884da020a4ca1332af38a7072b061e36281533af9f4e236d94d3c129daf6fe5b55241127537038eed
fa05d19bd6ba619bb3f9aabc05c439cd18d34544 test: Fix intermittent issue in mempool_compatibility (MarcoFalke)
Pull request description:
Fixes https://cirrus-ci.com/task/5141306890518528?command=ci#L6076
The version is too old to understand getmempoolinfo()[loaded], so it is never called when starting (See https://cirrus-ci.com/task/5141306890518528?command=ci#L5541)
ACKs for top commit:
achow101:
ACK fa05d19bd6ba619bb3f9aabc05c439cd18d34544
Tree-SHA512: e912d5dff6236d2d4ac608f9f3b3e255cc2b611f36d79bfe4e2a940709833a947c682d7703327887e1753eab30b95eb2615d7e2c21ce4bca4f089e717cbb51c4
fa69c2c78455fd0dc436018fece9ff7fc83a180d wallet: Do not treat default constructed types as None-type (MarcoFalke)
fac4e136fa3d0fab7fde900a6be921313e16e7a6 refactor: Change pointer to reference because it can not be null (MarcoFalke)
Pull request description:
Equating `0==None` and `""==None` is confusing, unneeded and undocumented
ACKs for top commit:
jonatack:
ACK fa69c2c78455fd0dc436018fece9ff7fc83a180d
achow101:
ACK fa69c2c78455fd0dc436018fece9ff7fc83a180d
Sjors:
tACK fa69c2c78455fd0dc436018fece9ff7fc83a180d modulo `unset`
Tree-SHA512: c4c8d0ad80c6697621d356a9545caf28ca2facc82bb2fa8e70eceb52372d25f0685237c73688c4b01da0e75d213c77c0d45011a8bdfe81ea783d85f045786dac
b1f59d55d920d2b35269b474762f94fec87bfb16 RPC/Wallet: unloadwallet: Clarify docs/error when both the RPC endpoint and wallet_name parameter specify a wallet (Luke Dashjr)
Pull request description:
Just documentation clarifications from #20448
ACKs for top commit:
MarcoFalke:
review ACK b1f59d55d920d2b35269b474762f94fec87bfb16
jonatack:
re-ACK b1f59d55d920d2b35269b474762f94fec87bfb16 per `git diff e8303a0 b1f59d5`
Tree-SHA512: ac068b0aa7ceed49496367fdd9425b59dbba18b56e89b26afc22a6c8ece51f0b92a169cacd55740b1cadab2b32f4f8e8700e609066ab7e59d3b53c7891da585e
9f08780dd7946b63476e9736745131db8e7f4e93 Use the correct incremental fee constant in bumpfee help (Jon Atack)
3f1e10b2b1cd11f7112fbad6355464bd4adbbc5c Update feeRate (BTC/kvB) to fee_rate (sat/vB) in wallet_bumpfee (Jon Atack)
1b3d7009280595108eb22ac1188bc4367804fc5d Allow zero-fee fundrawtxn and walletcreatefundedpsbt calls (Jon Atack)
Pull request description:
- Fixes https://github.com/bitcoin/bitcoin/pull/20305/files#r525406176. A check to raise an error on zero-fee txns was mistakenly extended in a0d4957 from the bumpfee and send{toaddress, many} RPCs to also include fundrawtransaction and walletcreatefundedpsbt. This commit re-overrides zero fee rate checking for these two RPCs, not only for the feeRate (BTC/kvB) arg to return to previous behavior, but also for the new fee_rate (sat/vB) arg. Negative fee rates will still raise "amount out of range" by the MoneyRange check in src/bitcoin-tx.cpp::AmountFromValue.
- Updates a wallet bumpfee test from feeRate (BTC/kvB) to fee_rate (sat/vB)
- Fixes https://github.com/bitcoin/bitcoin/pull/20305/files#r525405363 to use the correct incremental fee rate constant in the bumpfee help (thanks Marco Falke for the catch) and rectifies "1.000 sat/vB sat/vB" in the help to "1.000 sat/vB"
ACKs for top commit:
MarcoFalke:
review ACK 9f08780dd7946b63476e9736745131db8e7f4e93 🐾
promag:
Code review ACK 9f08780dd7946b63476e9736745131db8e7f4e93.
Xekyo:
Code review reACK 9f08780dd7946b63476e9736745131db8e7f4e93.
Tree-SHA512: 413dfb4f23ebaf3d2ef210dd04610a843272e64eabba428699f5de4d646a86ac4911dab66b5e2f5ebea53b76e4be8347ef40824c1592c750d5eaa12579d3cdf6
8f7b93047581c67f2133cdb8c7845471de66c30f Drop the leading 0 from the version number (Andrew Chow)
Pull request description:
Removes the leading 0 from the version number. The minor version, which we had been using as the major version, is now the major version. The revision, which we had been using as the minor version, is now the minor version. The revision number is dropped. The build number is promoted to being part of the version number. This also avoids issues where it was accidentally not included in the version number.
The CLIENT_VERSION remains the same format as previous as previously, as the Major version was 0 so it never actually got included in it.
The user agent string formatter is updated to follow this new versioning.
***
Honestly I'm just tired of all of the people asking for "1.0" that maybe this'll shut them up. Skip the whole 1.0 thing and go straight to version 22.0!
Also, this means that the terminology we commonly use lines up with how the variables are named. So major versions are actually bumping the major version number, etc.
ACKs for top commit:
jnewbery:
Code review ACK 8f7b930475
MarcoFalke:
review ACK 8f7b93047581c67f2133cdb8c7845471de66c30f 🎻
Tree-SHA512: b5c3fae14d4c0a9c0ab3b1db7c949ecc0ac3537646306b13d98dd0efc17c489cdd16d43f0a24aaa28e9c4a92ea360500e05480a335b03f9fb308010cdd93a436
as the feeRate argument should soon be deprecated.
Also loosen one test (and a similar one) that caused a one-off CI failure with:
expected message
'Insufficient total fee 0.00000141, must be at least 0.00001704 (oldFee 0.00000999 + incrementalFee 0.00000705)'
actual message
'Insufficient total fee 0.00000141, must be at least 0.00001712 (oldFee 0.00001007 + incrementalFee 0.00000705)'
A check to raise an error on zero-fee txns was mistakenly extended in commit
a0d4957 from the bumpfee and send{toaddress, many} RPCs to also include
fundrawtransaction and walletcreatefundedpsbt.
This commit overrides zero fee rate checking for these two RPCs, not only for
the feeRate (BTC/kvB) arg to return to previous behavior, but also for the new
fee_rate (sat/vB) arg.
7ffac12545328cadd92a3caec4f1c6ca7c127493 tests: shrink feature_taproot transfer of funds tx (Anthony Towns)
Pull request description:
When moving funds from node 1 to node 0 for the pre-activation tests, there can be a large number of inputs, potentially resulting in a tx that is larger than standardness rules allow, or that takes a long time to sign. This just takes the top 500 outputs, which is plenty (~90% of the wallet balance).
ACKs for top commit:
luke-jr:
utACK 7ffac12545328cadd92a3caec4f1c6ca7c127493
MarcoFalke:
cr ACK 7ffac12545328cadd92a3caec4f1c6ca7c127493
Tree-SHA512: 68445b4827dddb9a8e8614d61a68f5bbd7152557bf940be0a75741cb49deeff1566198da1a777ac66cb3fed93e64a30bf895875d6cc6ae9e48275e3febb620a6
c92387232f750397da7d131f262c150a608408c2 refactor: Extract ParseOpCode from ParseScript (João Barbosa)
Pull request description:
Seems more natural to have `mapOpNames` "hidden" in `ParseOpCode` than in `ParseScript`.
A second lookup in `mapOpNames` is also removed.
ACKs for top commit:
laanwj:
ACK c92387232f750397da7d131f262c150a608408c2
theStack:
re-ACK c92387232f750397da7d131f262c150a608408c2
Tree-SHA512: d59d1964760622cf365479d44e3e676aa0bf46b60e77160140d967e012042df92121d3224c7551dc96eff5ff3294598cc6bade82adb3f60d28810e18e60e1257
21f24336019d438e225c7bd6653871119883a4ee test: run mempool_spend_coinbase.py even with wallet disabled (Michael Dietz)
Pull request description:
Run the mempool spend coinbase test even when the wallet was not compiled, as proposed in #20078.
ACKs for top commit:
laanwj:
ACK 21f24336019d438e225c7bd6653871119883a4ee
Tree-SHA512: 301582c04376371cfa8f1ebb2418a4341b42ddcd9ad4f48b58bcf888d867a97bdc409972856b67a8339ac5e60124aefee82a049b4f7fc6bca7a18d7e92e090be
6b56c1f4d0d5857d9d61a81dc96db1b603c368b5 test: remove last_{block,header}_equals() in p2p_fingerprint.py (Sebastian Falbesoner)
136d96b71f94bde2c7471ed852d447ec008e3a30 test: use wait_for_{block,header} helpers in p2p_fingerprint.py (Sebastian Falbesoner)
Pull request description:
This small PR takes use of the message receiving helper functions `wait_for_block()` and `wait_for_header()` (from module `test_framework.p2p`) in the test `p2p_fingerprint.py`. It also simplifies the checks for very old stale blocks/headers requests by getting rid of the functions `last_block_equals()` and `last_header_equals()` and rather only testing that not any blocks/headers message is received at all. Unneeded sending of requests are also removed and calls to time.sleep(...) substituted by ping syncs.
ACKs for top commit:
guggero:
ACK 6b56c1f4
Tree-SHA512: 9114db70f3804adad4ab658236762d4fa73fef91158c5756dd1af2d24196ea740451b0028667e0c4047f1f89fe1355031921d3dfb973acc1370052a4bc12c2ab
faaf9c58e4aa809019d4ca12747dd47411988e37 remove CRPCCommand constructor that takes rpcfn_type function pointer (MarcoFalke)
fa19bb2cd8c575593583138a84e6bb3444d6196d remove dead rpc code (MarcoFalke)
Pull request description:
Remove the CRPCCommand arguments, now that they are asserted to be equal and thus redundant
### Future work
> Here or follow up, makes sense to also assert type of returned UniValue?
Sure, but let's not get ahead of ourselves. I am going to submit any further works as follow-ups, including:
* Removing all python regex linters on the args, now that RPCMan can be used to generate any output, including the cli.cpp table
* Auto-formatting and sanity checking the RPCExamples with RPCMan
* Checking passed-in json in self-check. Removing redundant checks
* Checking returned json against documentation to avoid regressions or false documentation
* Compile the RPC documentation at compile-time to ensure it doesn't change at runtime and is completely static
### Bugs found
* The assert identified issue #18607
* The changes itself fixed bug #19250
ACKs for top commit:
fjahr:
tested ACK faaf9c58e4aa809019d4ca12747dd47411988e37
promag:
Tested ACK faaf9c58e4aa809019d4ca12747dd47411988e37.
ryanofsky:
Code review ACK faaf9c58e4aa809019d4ca12747dd47411988e37. Two obviously good simplifications.
Tree-SHA512: 5de3b440f7b2ed2c3e86655d4f0e2e5df9c67e8ce3c7817d5ea5311d1a38690f2f3e28fab41aad6936be9fc884326d037e5f19e85d4d2fe281474dada13911ee
46756a69877ab7d56f3b05f8c5a8899eb24d9ffd depends: Fix PYTHONPATH setting in config.site.in (Carl Dong)
618cbd2c1a630a60bed9212718dce78fe5f50108 lint: Also lint files with shellcheck directive (Carl Dong)
6c7e8f067dcf4c5d793d162aeb84f074f9a14664 depends: Allow relative CONFIG_SITE path env var (Carl Dong)
Pull request description:
This changeset:
1. Allows the `CONFIG_SITE` env var to be a relative path rather than requiring an absolute one
2. Enables linting of the `config.site.in` file with `shellcheck` in our linting scripts
3. Sets the `PYTHONPATH` var sensibly in `config.site.in`
Please see commit messages for more details
ACKs for top commit:
laanwj:
ACK 46756a69877ab7d56f3b05f8c5a8899eb24d9ffd
Tree-SHA512: 744089b9f6e5604e56466d9a3e64563f9183a70f7e300ac9ae6248f0f17c0b53fe28a2c41d43c5ffe5da825f53c2ca21f21aacba0579442da3056fb0c4b81454
It is unnecessary to upgrade to FEATURE_HD_SPLIT if this feature is
already supported by the wallet. Because upgrading to FEATURE_HD_SPLIT
actually requires upgrading to FEATURE_PRE_SPLIT_KEYPOOL, users would
accidentally be upgraded to FEATURE_PRE_SPLIT_KEYPOOL instead of nothing
being done.
Fixes the issue described at
https://github.com/bitcoin/bitcoin/pull/20403#discussion_r526063920
Removes the leading 0 from the version number. The minor version, which
we had been using as the major version, is now the major version. The
revision, which we had been using as the minor version, is now the minor
version. The revision number is dropped. The build number is promoted to
being part of the version number. This also avoids issues where it was
accidentally not included in the version number.
The CLIENT_VERSION remains the same format as previous as previously,
the Major version was 0 so that was never a factor in CLIENT_VERSION.
97c738ff1b592270491551cc0a43472d244ffbb0 [tests] Recommend f-strings for formatting, update feature_block to use them (Anthony Towns)
8ae9d314e9af7bcce1e8bc52f0317b9d565109bf Bump minimum python version to 3.6 (Anthony Towns)
Pull request description:
Python 3.5 has reached [end-of-life](https://devguide.python.org/#status-of-python-branches) as of September 2020, and 3.6 has some moderately nice [features](https://docs.python.org/3/whatsnew/3.6.html):
- `f'x = {x}'` as an alternative to `'x = {}'.format(x)` format strings (cf https://github.com/bitcoin/bitcoin/pull/13718#issuecomment-406591027)
- underscore separators for large numbers, like `1_234_567`
- improvements to async
- improvements to typing module
Note that 3.6 is not available in xenial (16.04), but is available in bionic (18.04), while focal (20.04) has 3.8. CentOS 7 and 8 have 3.6.8, Debian stable has 3.7.3, and [gentoo and arch already had 3.6 and 3.7 in 2018](https://github.com/bitcoin/bitcoin/pull/14954#issuecomment-447118707).
ACKs for top commit:
MarcoFalke:
re-ACK 97c738ff1b
Tree-SHA512: ec7fce68845edde4d61a42de12c065fd49e5217311a6fda1323206f091a0afd50f293645dffc27d420127e4e5deb864e953f1b67eff735a0dfbbedd7899a9d60
