Commit Graph

2845 Commits

Author SHA1 Message Date
Robert Zaremba b18a033a17
Clean Any interface (#8167)
* Clean Any interface

+ removed Any.Pack method. This method is not needed, because we have specialized
  functions for createing new Any values. It could be used inappropriately with existing
  Any objects.

* removed deprecated PackAny function

* fix linter issue

* update nil handling

* NewAnyWithValue returns error on nil instead of panic

* NewMsgCreateValidator: handle nil pubkey

* Remove AsAny and tx builder workarounds

* fix linter issue

* Add AsAny methods to TxBuilder and StdTxConfig, but keep intoAny interface private

* remove tx.PubKeyToAny

* cosmetic updates

* fix method interface

* move ProtoTxProvider to x/auth/tx
2020-12-18 14:55:25 +00:00
Jack Zampolin 75bc312ffd
Update default historical header number for stargate (#8178)
* Update default historical header number

* Update x/staking/types/params.go

Co-authored-by: Amaury <amaury.martiny@protonmail.com>

* fix tests

* duh

Co-authored-by: Federico Kunze <31522760+fedekunze@users.noreply.github.com>
Co-authored-by: Amaury <amaury.martiny@protonmail.com>
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>
Co-authored-by: Federico Kunze <federico.kunze94@gmail.com>
2020-12-17 19:50:03 +00:00
Aditya 731be71379
Fix IBC upgrade: manually tested (#8187)
* commit at plan.Height key

* fix upgrade tests

* remove debugging prints

* Update x/ibc/light-clients/07-tendermint/types/upgrade.go

Co-authored-by: colin axnér <25233464+colin-axner@users.noreply.github.com>

Co-authored-by: colin axnér <25233464+colin-axner@users.noreply.github.com>
2020-12-17 17:32:19 +00:00
Prathyusha Lakkireddy be573cb0ce
change gentx cmd amount field to arg from flag (#8183)
* Read gentx amount as argument

* Update gentx command usage

* Update gentx tests

* Update docs of gentx

Co-authored-by: Alessio Treglia <alessio@tendermint.com>
2020-12-17 17:27:30 +01:00
Jordan Sexton 3781028e85
docs: typo fix (#8172)
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>
2020-12-16 13:44:34 +00:00
Federico Kunze 1c6881def8
x/ibc: fix ClientUpdateProposal unpacker (#8170)
* x/ibc: fix ClientUpdateProposal unpacker

* rm duplicate line
2020-12-16 10:41:20 +01:00
colin axnér 829e068545
x/upgrade: fix software upgrade proposals from automatically failing, add unpackinterfaces function (#8169)
* fix unpack interfaces bug

* remove unnecessary ;
2020-12-15 19:06:09 +01:00
Jun Kimura 039036f1cd
add Increment method to Height interface (#8157)
Co-authored-by: colin axnér <25233464+colin-axner@users.noreply.github.com>
2020-12-15 12:26:43 +00:00
Amaury cf86c567c7
Add msg on CLI for migrating GenesisDoc (#8164)
* Add msg on CLI for migrating GenesisDoc

* Fix build

* Better indentation

* Add table tests

* typo

* Rename variables

* Fix validate tests

* Add warning println

Co-authored-by: Cory <cjlevinson@gmail.com>
2020-12-14 22:51:23 +00:00
Robert Zaremba a3ae6e3704
Combine client.ReadTxCommandFlags with GetClientContextFromCmd (#8155)
* Update codebase to simplify clientCtx loading from cmd

* make ReadTxCommandFlags and ReadQueryCommandFlags private

* fix build error

* fix conflicts
2020-12-14 22:09:51 +00:00
Robert Zaremba 3a9e696bbf
fix: Signature only flag bug on tx sign command 7632 (#8106)
* fix: Signature only flag bug on tx sign command 7632

* Update client/context.go

Co-authored-by: Cory <cjlevinson@gmail.com>

* Update client/context.go

Co-authored-by: Cory <cjlevinson@gmail.com>

* use named return value and closure (#8111)

This is to correctly handle deferred Close()
calls on writable files.

* set the right 'append' logic for signing transactions

* cleanup

* update tx.Sign interface by adding overwrite option

* Update Changelog

* sign command cleanup

* implementation and changelog update

* fix SignTx and tx.Sign calls

* fix: sign didn't write to a file

* update flags description

* Add tx.Sign tests

* fix grpc/server_test.go

* Update client/tx/tx.go

Co-authored-by: Cory <cjlevinson@gmail.com>

* changelog update

* Add test to verify matching signatures

* cli_test: add integration tests for sign CMD

* add output-file flag test

* add flagAmino test

* Update x/auth/client/cli/tx_sign.go

Co-authored-by: Alessio Treglia <alessio@tendermint.com>

* Update x/auth/client/cli/tx_sign.go

* update amino serialization test

* TestSign: adding unit test for signing with different modes

* Add test with Multi Signers into Robert's TxSign PR (#8142)

* Add test with Multi Signers

* remove true false

* Use SIGN_MODE_DIRECT

* Fix litn

* Use correct pubkeys

* Correct accNum and seq

* Use amino

* cleanups

* client.Sign: raise error when signing tx with multiple signers in Direct

+ added more unit tests

* add more tests

* Update client/tx/tx_test.go

Co-authored-by: Cory <cjlevinson@gmail.com>

* fix TestGetBroadcastCommand_WithoutOfflineFlag

* Any.UnsafeSetCachedValue

* fix note packed messages in tx builder

* reorder unit tests

* Changelog update

* cleaning / linting

* cli_tes: copy validator object instead of modifying it's shared codec

* x/auth cli_test: remove custom codec creation in tests

* Update CHANGELOG.md

* updates to CHANGELOG.md

* remove unused method

* add new instance of transaction builder for TestSign

Co-authored-by: Cory <cjlevinson@gmail.com>
Co-authored-by: SaReN <sahithnarahari@gmail.com>
Co-authored-by: Alessio Treglia <alessio@tendermint.com>
Co-authored-by: Amaury <amaury.martiny@protonmail.com>
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>
2020-12-14 21:44:15 +00:00
Aditya 5aaae12b6d
support upgrade on same revision (#8165)
Co-authored-by: colin axnér <25233464+colin-axner@users.noreply.github.com>
2020-12-14 19:31:45 +00:00
Andrey Kuprianov a821fe4a61
Model-based tests for relay functions of ICS-20 token transfer (#8145)
* start on MBT for ICS20: setting and checking bank balances

* add bank struct for subtracting banks

* reconstruct ibc denominations in the bank

* add some static tests with bank changes tracking

* small fixes

* better error handling

* add Jsonatr transform from Apalache conterexample into OnRecvPacket test

* add example Apalache CE and transformed test

* changed apalache-to-recv-test.json to output arrays instead of records

* add datastructures for parsing TLA+ tests

* remove accidentally committed code

* add conversion from TLA+ structs to Go structs

* encode abstract ids into addresses via hashes

* first run of auto-generated MBT tests

* first run of auto-generated MBT tests: fix ports and channels

* fix small inconsistencies

* fix mbt_relay_test by not setting the bank balances in every iteration

* add test for onTimeoutPacket

* add handling of OnRecvAcknowledgement to mbt relay test

* add handling of SendTransfer

* add relay-test.json

* revert manual changes in relay-test.json

* fix handling of denominations for SendTransfer

* setup two test channels A-B, B-C; fix escrow address encoding

* a test for all handlers passing

* generalize denom handling to arbitrary length + failing denom test

* rename test function

* MBT test for unsecrow tokens

* add model-based generated tests

* add model-based tests (prev commit: addded model)

* transformed json tests with jsonatr

* modify mbt_relay_test.go to execute all MBT tests

* cleanup

* move jsonatr transforms into another dir

* add MBT_README.md

Co-authored-by: Federico Kunze <31522760+fedekunze@users.noreply.github.com>
2020-12-11 17:35:44 +00:00
Amaury bce5da0e84
Use SignModeLegacyAminoJSON when signer is ledger key (#8136)
* Use SignModeLegacyAminoJSON when signer is ledger key

* Fix tests

* Fix lint

* Fix tests

* Add warning message

Co-authored-by: Alessio Treglia <alessio@tendermint.com>
2020-12-11 13:54:50 +00:00
Aleksandr Bezobchuk 521380abd6
x/auth: atlas manifest (#8140) 2020-12-10 17:02:29 +01:00
Aleksandr Bezobchuk 10f846217d
atlas: x/auth v0.39.1 (#7996) 2020-12-10 10:40:42 -05:00
Aleksandr Bezobchuk 9104a72d50
x/bank: update atlas manifest (#8137) 2020-12-10 16:12:09 +01:00
Alessio Treglia 056f416d2b
use testutil in test cases (#8130)
Also replace defer calls with
testing.T.Cleanup()
2020-12-10 12:56:55 +00:00
Anil Kumar Kammari e321317c20
add page flags for staking validators (#8103)
* add page flags for staking validators

* add test

* fix test

* add build flag

Co-authored-by: aleem1413 <aleem@vitwit.com>
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>
2020-12-10 12:26:44 +00:00
Alessio Treglia f51f5e6784
testutil: new TempFile function, simplify WriteToNewTempFile (#8123)
Files returned by WriteToNewTempFile are cleaned up
automatically at the end of a test case execution.
WriteToNewTempFile now relies on the TB.TempDir()
function provided by the testing std package.

TempFile returns a temporary file that can be used
within a test case and is automatically removed
at the end of the test execution.
2020-12-09 18:27:20 +00:00
colin axnér af401359eb
fix ibc-transfer receiving denom bug (#8119)
* fix receiving denom bug

* Update x/ibc/applications/transfer/keeper/relay.go

* add testing sending 2 hops and back one

Co-authored-by: Aleksandr Bezobchuk <alexanderbez@users.noreply.github.com>
2020-12-09 15:02:59 +00:00
Amaury 58491a5660
Add UnpackInterfaces to BroadcastReq (#8118)
* add test case for decoding & re-encoding a full transaction using amino

* drop equal assertion for tx and txRequest

* Fix BroadcastReq UnpackInterfaces

* Remove unrelated files

* order imports

* sort imports again

Co-authored-by: Cory Levinson <cjlevinson@gmail.com>
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>
2020-12-09 11:05:12 +00:00
Robert Zaremba fe41718047
Robert/api clientctx (#8107)
* rename clientCtx.PrintOutput to PrintObject

* rename clientCtx.PrintOutputLegacy to PrintObjectLegacy

* Changelog update

* Rename PrintObject to PrintProto
2020-12-08 20:17:40 +00:00
Riccardo Montagnin e843878920
Recover private validator key (#8099)
* Recover private validator key
Added the ability to recover the private validator key from a given mnemonic when initializing the node

* Added CHANGELOG entry

* Reverted dependencies

* Added tests

* Fixed mnemonic checking as suggested and added tests

* Run make format and fixed go.sum checksum

* Run make format

* fix imports

* fix TestInitializeNodeValidatorFilesFromMnemonic

* Update CHANGELOG.md

Co-authored-by: Alessio Treglia <quadrispro@ubuntu.com>

Co-authored-by: Alessio Treglia <alessio@tendermint.com>
Co-authored-by: Alessio Treglia <quadrispro@ubuntu.com>
2020-12-08 17:22:43 +00:00
Emmanuel T Odeke e38a6df9cd
x/ibc/light-clients: simplify max time comparison (#8089)
The prior code that tried to get the newest/larger time
between the too performed:
* 2 time.Time.UnixNano() retrievals: 2 multiplications, 2 additions
* 1 math.Max comparison
* 1 time.Unix(0, minTime) creation

but really this code could just use native operations on:
time.Time.After() simply.

This now becomes a single operation, single comparison for the same effect.
2020-12-08 13:47:20 +01:00
Robert Zaremba b219c54c2d
Move and update codec.MarshalAny functions to codec.Marshaler interface (#8080)
* Changelog update

* Rename codec.MarshalAny

* move codec.MarshalInterface to codec.Marshaler

* fix tests

* Update amino_codec for compliance with MarshalerInterface

* update tests and comments

* add tests

* change order of args in UnmarshalInterface to a canonical one

* uplift MarshalInterface to take ProtoMessage as an argument

* wip

* add nil check

* make tests working

* tests cleanup

* add support for *JSON methods

* Update changelog

* linter fixes

* fix test types

* update evidence genesis_test

* adding test

* review updates

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>
2020-12-08 09:27:08 +00:00
Sunny Aggarwal da6b7f7755
removed gov docs bug (#8105) 2020-12-07 21:33:27 +00:00
Emmanuel T Odeke 291d966fe9
x/ibc/core/23-commitment/types: fix MerkleProof.Empty comparisons (#8092)
* x/ibc/core/23-commitment/types: fix MerkleProof.Empty comparisons

Fixes invalid pointer creation, reduces on unnecessary allocations
inside MerkleProof.Empty, and changes the method to a pointer; the
invalid pointer creation was symptomatic of broad use of values.

With this change we have improvements whose benchmarks produce:

```shell
name     old time/op    new time/op    delta
Empty-8     311ns ± 5%     232ns ± 5%  -25.49%  (p=0.000 n=20+19)

name     old alloc/op   new alloc/op   delta
Empty-8     56.0B ± 0%      8.0B ± 0%  -85.71%  (p=0.000 n=20+20)

name     old allocs/op  new allocs/op  delta
Empty-8      3.00 ± 0%      1.00 ± 0%  -66.67%  (p=0.000 n=20+20)
```

Fixes #8091

* Move Empty godoc to right place + add comments for blank*
2020-12-07 20:57:15 +00:00
Aditya 971d253214
Implement Connection-specified delay (#8069)
* start with initialization and metadata

* start by fixing delay period during connection handshake

* fix connection handshake tests

* add delay period logic to packet verification

* proto format

* fix err issue

* appease linter

* document upgrade special case

* Update x/ibc/light-clients/07-tendermint/types/client_state.go

Co-authored-by: colin axnér <25233464+colin-axner@users.noreply.github.com>

* Update x/ibc/light-clients/07-tendermint/types/store.go

* add sanity check

* fix build

* fix tests

Co-authored-by: colin axnér <25233464+colin-axner@users.noreply.github.com>
Co-authored-by: Federico Kunze <31522760+fedekunze@users.noreply.github.com>
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>
Co-authored-by: Colin Axner <colinaxner@berkeley.edu>
2020-12-07 12:13:06 +00:00
Mark Jackson de114773ee
fix typo (#8097)
Co-authored-by: Jonathan Gimeno <jgimeno@gmail.com>
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>
2020-12-07 11:26:09 +00:00
Emmanuel T Odeke a8c3b4414d
x/bank/keeper: fix a missing gRPC error in AllBalances (#8085)
* x/bank/keeper: fix a missing gRPC error in AllBalances

Fixes an incoherent return which had:
    (non-nil value, non-nil-non-grpc error)
to
    (nil value, non-nil-gRPC error)

and it is a follow-up of PR #7814.

* types/query: fix pagination test (#8096)

Co-authored-by: Alessio Treglia <alessio@tendermint.com>
2020-12-07 01:32:59 -08:00
colin axnér c8a9da1d27
increase ibc basic genesis validation (#8081)
* increase client basic genesis validation

* add connection/channel genesis validation

* fix tests

* apply @AdityaSripal suggestion

Co-authored-by: Christopher Goes <cwgoes@pluranimity.org>
2020-12-05 21:10:15 +00:00
Anil Kumar Kammari 4a233b8dcf
Rename GRPCRouter (#8079)
* rename GRPCRouter

* Update store/types/store.go

Co-authored-by: Robert Zaremba <robert@zaremba.ch>

* Fix gofmt

Co-authored-by: Robert Zaremba <robert@zaremba.ch>
2020-12-04 15:06:50 +00:00
Frojdi Dymylja 7ec3bcd23a
fix: bank gRPC error status codes (#7814)
Co-authored-by: SaReN <sahithnarahari@gmail.com>
Co-authored-by: Alessio Treglia <alessio@tendermint.com>
2020-12-04 12:19:29 +00:00
Amaury 1b00c01b70
Audit through legacy endpoints to find breaking changes (#8037)
* Add error msg on staking

* Add tests for legacy staking and gov

* Add test for encode

* Fix broadcast too

* Add comments

* update changelog

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>
2020-12-03 23:33:32 +00:00
Aleksandr Bezobchuk 5291a8ff31
Refactor Logging using Zerolog (#8072)
* init commit

* server: use flags

* server: godoc++

* updates

* baseapp: update logging

* logging updates

* x/bank: update logging

* logging updates

* lint++

* logging updates

* logging updates

* logging updates

* logging updates

* cl++
2020-12-03 23:17:21 +00:00
SaReN 183593ff6d
Update signbatch multisig to work online (#7801)
* add test for signbatch multisig

* update test

* fix sign batch multisig

* update offline usage

* address comments

Co-authored-by: Alessio Treglia <alessio@tendermint.com>
2020-12-03 09:48:17 +00:00
Robert Zaremba 6040d1b88b
fix: Metadata is not initialized in x/bank InitGenesis #7951 (#8065)
* fix: Metadata is not initialized in x/bank InitGenesis #7951

* remove commented code

Co-authored-by: Aleksandr Bezobchuk <alexanderbez@users.noreply.github.com>
2020-12-03 08:39:11 +00:00
Aleksandr Bezobchuk bac31becb3
evidence: fix query command (#8066)
* evidence: fix query command

* evidence: add CLI tests

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>
2020-12-02 18:08:16 +00:00
MD Aleem b6c8d5ea9f
Add tx broadcast gRPC endpoint (#7852)
* WIP tx/broadcast grpc endpoint

* fix lint

* fix proto lint

* Update service.proto

* resolve conflicts

* update service.proto

* Update service.proto

* review changes

* proto lint

* Switch to txraw

* Add check breaking at the end

* Fix broadcast

* Send Msg on SetupSuite

* Remove proto-check-breaking

* 1 validator in test

* Add grpc server tests for broadcast

* Fix grpc server tests

* Add some changes

* Add ress comments

* Add table tests for tx service

* Add test for mode

* Add simulate tests

* Add build flag back

* Revert custom stringer for enum

* Remove stray logs

* Use /txs/{hash}

Co-authored-by: Amaury Martiny <amaury.martiny@protonmail.com>
Co-authored-by: Aleksandr Bezobchuk <alexanderbez@users.noreply.github.com>
2020-12-02 17:50:40 +00:00
MD Aleem a51eac4f15
Fix QueryByEvents with multiple events and empty pagination request (#8029)
* fix pagination issue

* Fix querying with multiple events

* reuse ParsePagination

* update tests

* change event type to array

* fix test

* review changes

* add test case for escape params

* review changes

* resolve conflicts

* fix test

* fix test

Co-authored-by: anilCSE <anil@vitwit.com>
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>
2020-12-01 04:18:35 +00:00
Amaury 7ad2aab2c4
Add panic handler on queries (#8039)
* Add test that panics

* Add panic in abci query

* Move proto gen files to correct place

* Add panic handler in grpc server

* Fix test

* Fix build

* Use %v

* Better panic message

* Fix tests

Co-authored-by: Aleksandr Bezobchuk <alexanderbez@users.noreply.github.com>
2020-11-30 16:59:35 +00:00
colin axnér bcb3240d06
Use generated client identifiers (#8034)
* add client identifier generation

* update proto and start fixing tests

* fix ibc tests

* fix auth rest test

* update spec

* fix lint

* add parsing tests and fix bugs

* fix regexp

* add godoc

* address @AdityaSripal review suggestions for identifier parsing

* address rest of @AdityaSripal's review comments

* remove unnecessary comment

* typos

* fix lint

* Apply suggestions from code review

Co-authored-by: Aditya <adityasripal@gmail.com>

* add more heigh tests as per @AdityaSripal suggestion

Co-authored-by: Aditya <adityasripal@gmail.com>
2020-11-30 15:52:45 +00:00
colin axnér ed9fc058f1
Add an IBC prefix to transfer escrow addresses (#7967)
* add IBC prefix to escrow addresses

* use ADR 028 AddressHash construction

* remove extra space

* apply @AdityaSripal suggestion; prefix from ibc -> ibc-transfer-escrow-prefix

* Use alternative 1 proposed by @andrey-kuprianov

* anticpate necessary build fix

* add escrow address issue link into module.go

* Update x/ibc/applications/transfer/types/keys.go

Co-authored-by: Andrey Kuprianov <59489470+andrey-kuprianov@users.noreply.github.com>

* Update x/ibc/applications/transfer/types/keys.go

Co-authored-by: Andrey Kuprianov <59489470+andrey-kuprianov@users.noreply.github.com>

* apply @andrey-kuprianov review suggestions

Deduplicate code into a helper function as suggested. Add unit tests for max transfer channels test.

Co-authored-by: Andrey Kuprianov <59489470+andrey-kuprianov@users.noreply.github.com>
2020-11-26 13:44:54 +00:00
yihuang 512b533242
cli: ParseCoin doesn't do normalize (#7954)
follow up on https://github.com/cosmos/cosmos-sdk/pull/7777
ParseCoin need to be treated similarly.

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>
2020-11-25 18:02:10 +00:00
Amaury a9dd334c34
Fix legacy querying tx ("unregistered type" bug) (#7992)
* Add tests for query txs

* Add test for IBC

* Refactor checkSignModeError

* Fix lint

* Add successful IBC test

* Remove logs

* break

* Remove known errors

* Update error message

* Better comments

* Revert variable renaming

* Fix lint

* Add mention of gRPC as TODO
2020-11-25 12:02:31 +00:00
Amaury 1b3ce2c1d1
CLI `migrate` command for x/{upgrade,params} proposals (#7875)
* Add v038 upgrade types

* Add migrate x/upgrade

* remove nolint

* Add ParameterChangeProposal

* Revert change

* Don't register crypto twice

Co-authored-by: Anil Kumar Kammari <anil@vitwit.com>
Co-authored-by: Federico Kunze <31522760+fedekunze@users.noreply.github.com>
2020-11-24 23:32:32 +00:00
Aditya c15884a204
Rename Version to Revision in IBC Height (#8020)
* rename Version to Revision in ibc Height

* lint

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>
2020-11-24 15:38:24 +00:00
colin axnér 88e03e4f40
Deterministic connection and channel identifiers (#7993)
* add generate identifier functions for connection and channel

* update proto types and begin open init changes

remove unnecessary field from open init msgs. Update connectionopeninit handshake, begin updating channel handshake

* finish connection handshake chanes and some channel handshake changes

Finish updating connection handshake changes, update genesis for connection and channel, some channel handshake changes, fix build for tests but still failing

* finish channel handshake changes

* fix more tests

* fix connection handshake tests

* fix more tests

* fix build

* changes from self review

* address @fedekunze review suggestions

* update spec

* fix build

* fix tests

* Update x/ibc/testing/chain.go

Co-authored-by: Aditya <adityasripal@gmail.com>

* Update x/ibc/core/03-connection/types/msgs.go

Co-authored-by: Aditya <adityasripal@gmail.com>

* address @AdityaSripal comments

* reflect spec changes

* address @AdityaSripal review suggestions

* nit

* add connection/channel identifier parsing and validation as per @AdityaSripal suggestion, cc @fedekunze

* Fix auth rest test

Change dummy channel id to a valid channel id given the updated stricter channel identifier checks cc @amaurymartiny

Co-authored-by: Aditya <adityasripal@gmail.com>
2020-11-24 15:28:20 +00:00
Amaury 13bc504bec
docs: Add REST endpoints migration guide (#8011)
* Add REST endpoints migration guide

* add bank, distrib, evidence

* Add slashing, mint

* Add staking

* Add query

* Add todo

* Typos

* Add link to interact node

* grammar

* Better wording

* Update docs/migrations/rest.md

Co-authored-by: Robert Zaremba <robert@zaremba.ch>

* Update docs/migrations/rest.md

* Add footnote

Co-authored-by: Robert Zaremba <robert@zaremba.ch>
2020-11-24 14:34:20 +00:00