Update elements to Bitcoin Core version 0.17.0

[stevenroose]

• Rebase to or merge from Core v0.17 into elements.
  • 1. Take Bitcoin Core 0.17 branch, at .0 release.
  • In parallel-ish, using a "wiped history" strategy, apply each cleanly, with configurable flags to stay compatible with Bitcoin:
  • 2. Apply custom chains++ arguments (testchains) (@jtimon) [0.17] QA: Use resgtest2 chain instead of regtest for rpc tests #432
  • 3. Apply blocksigning (@instagibbs) [0.17] Signed blocks feature #478
  • 4. Apply peg functionality @stevenroose) [0.17] Add pegin validation #458
  • 5. Apply additional op codes (@stevenroose) [0.17] Add new Elements opcodes #495
  • After:
  • 6. CT/CA consensus/policy, with no wallet support (@instagibbs) [0.17, WIP] Confidential Assets #503
  • 7. Issuance consensus/policy (@instagibbs) [0.17, WIP] Confidential Assets #503
  • 8. CT/CA wallet functionality (@instagibbs) [0.17, WIP] Confidential Assets #503
  • And finally:
  • 9. Peg-out authorization support (@instagibbs) [0.17] PAK Enforcement, as policy #484
• Update integration tests that make use of changed API functionality.
• height in header [0.17] blockheaders include block height, nodes validate it #431
• mandatory coinbase destination [0.17] Mandatory coinbase feature #430
• connecting coinbase output in genesis block [0.17] Connect gen block tx to db, don't validate gen block #429
• Moving scriptWitness back into its own witness structure we can expand with other fields, such as peg_in_witness, output witnesses, etc. (@stevenroose) [0.17] Add Elements-style witness structure #494
• Get rid of non-segwit serialization format [0.17] Add Elements-style witness structure #494
• Parent chains without POW (elements to elements)
• add initialfreecoins [0.17] Add initialfreecoins option, default of 0 #467
• CommitToArguments? (introduced in db42451, edited later)
• mandatory v5 blocks [0.17] Block v4 mandatory #470
  - [ ] Audit log I don't think we want this anymore - Greg
• option for always-on-rbf [0.17] Full RBF support #481
• Update secp to secp-zkp update secp to secp-zkp 53ad841cafa3bcb94b65409aec91fd7043533cf7 #482
• forward port of Fix progress reporting & initialblockdownload Blockstream/liquid#6 and Validation: stop logging fake pow data Blockstream/liquid#8 (with appropriate gating behind g_signed_blocks)
• Liquid v1 fedpeg script support [0.17] Add Liquid v1 based script matching functionality #497
• Segwit/CSV always-on for custom chains. Done upstream in d618458 [0.17] Activate CSV from genesis block for custom chains #505
  Cosmetic/Branching:
• Rename binaries/log messages to elements [0.17] Change branding from bitcoin to elements #521
• default chain becomes elementsregtest [0.17] Default to elementsregtest, when syncing liquid, find cookie #520

[instagibbs]

historically we'e rebased on top to keep the history easier to reason about. Open to other strategies of course.

[instagibbs]

I'm upgrading this to 0.17.0. I'm thinking of a strategy such as:

1. Take Bitcoin Core 0.17 branch, at .0 release.
   In parallel-ish, using a "wiped history" strategy, apply each cleanly, with configurable flags to stay compatible with Bitcoin:
2. Apply custom chains++ arguments (testchains)
3. Apply blocksigning
4. Apply peg functionality
5. Apply additional op codes
   After:
6. CT/CA consensus/policy, with no wallet support
7. Issuance consensus/policy
8. CT/CA wallet functionality
   And finally:
9. Peg-out authorization support

Each part can basically be done simultaneously in reality aside from 4/5, just requiring some serious rebasing.

[jtimon]

I would like to take 2 and 3.

[instagibbs]

I'll do 6/7/8.

@stevenroose 4/5 might be good to do.

[instagibbs]

@jtimon I'm thinking we should also apply 9 on top of the rebase, not before. We should just support script descriptors from the start.

[stevenroose]

@instagibbs Perfect, 4/5 it is! An adventure for sure :)

[instagibbs]

Other assorted tasks:
1) height in header #431
2) mandatory coinbase destination #430
3) connecting coinbase output in genesis block #429
4) Moving scriptWitness back into its own witness structure we can expand with other fields, such as peg_in_witness, output witnesses, etc.
5) Get rid of non-segwit serialization format

[instagibbs]

6. Parameterize block subsidy (to set it to 0 by default) [0.17] add block subsidy argument to allow different/non-inflation chains #443
7. "initialfreecoins"
8. update README
9. Make block version 5 mandatory
10. option for always-on-rbf
11. Audit log
12. forward port of Fix progress reporting & initialblockdownload Blockstream/liquid#6 and Validation: stop logging fake pow data Blockstream/liquid#8 (with appropriate gating behind g_signed_blocks)

[luke-jr]

option for always-on-rbf

Dunno if you'd prefer to rebase this from the old branch, or it might make more sense to just merge txrepl_fullrbf from Knots to simplify?

[dongcarl]

@luke-jr this one: bitcoinknots/bitcoin@f5c7ca2?

[luke-jr]

See link in above comment

[instagibbs]

heck if the feature is maintained yes we can just merge it