Make miniscript GetWitnessSize accurate for tapscript #28651

1. 
   sipa commented at 7:22 PM on October 13, 2023: member

   So far, the same algorithm is used to compute an (upper bound on) the maximum witness size for both P2WSH and P2TR miniscript. That's unfortunate, because it means fee estimations for P2TR miniscript will miss out on the generic savings brought by P2TR witnesses (smaller signatures and public keys, specifically).

   Fix this by making the algorithm use script context specification calculations, and add tests for it. Also included is a cleanup for the tests to avoid mutable globals, as I found it hard to reason about what exactly was being tested.

2. test: remove mutable global contexts in miniscript fuzzer/test 7ed2b2d430
3. test: add tests for miniscript GetWitnessSize 8be9851408
4. 
   DrahtBot commented at 7:22 PM on October 13, 2023: contributor

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5. miniscript: make GetWitnessSize accurate for tapscript b22810887b
6. sipa force-pushed on Oct 13, 2023
7. DrahtBot added the label CI failed on Oct 13, 2023
8. DrahtBot removed the label CI failed on Oct 13, 2023
9. DrahtBot added the label CI failed on Oct 14, 2023
10. DrahtBot removed the label CI failed on Oct 14, 2023
11. 
    darosior commented at 11:24 AM on October 15, 2023: member

    Concept ACK. Good catch. GetWitnessSize ended up being merged with #26567 but i forgot to update it in #27255.

12. fanquake added this to the milestone 26.0 on Oct 15, 2023
13. darosior approved
14. 
    darosior commented at 12:01 PM on October 15, 2023: member

    ACK b22810887b3840ad0fcb424ea7e16d2d195767d9

    Nice cleanup too.

15. fanquake requested review from achow101 on Oct 17, 2023
16. 
    achow101 commented at 10:22 PM on October 17, 2023: member

    ACK b22810887b3840ad0fcb424ea7e16d2d195767d9

17. DrahtBot removed review request from achow101 on Oct 17, 2023
18. achow101 merged this on Oct 17, 2023
19. achow101 closed this on Oct 17, 2023

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20. Frank-GER referenced this in commit 1d8dd76735 on Oct 21, 2023
21. bitcoin locked this on Oct 16, 2024

Contributors

sipaDrahtBotdarosiorachow101

Milestone
26.0