MA Policies Whitelist

[Cmdv]

Description

This is the first part of #1600 adding a whitelist for MA Policies and renaming:
KeepMetadataNames -> WhitelistMetadataNames

Checklist

• Commit sequence broadly makes sense
• Commits have useful messages
• New tests are added if needed and existing tests are updated
• Any changes are noted in the changelog
• Code is formatted with fourmolu on version 0.10.1.0 (which can be run with scripts/fourmolize.sh)
• Self-reviewed the diff

Migrations

• The pr causes a breaking change of type a,b or c
• If there is a breaking change, the pr includes a database migration and/or a fix process for old values, so that upgrade is possible
• Resyncing and running the migrations provided will result in the same database semantically

If there is a breaking change, especially a big one, please add a justification here. Please elaborate
more what the migration achieves, what it cannot achieve or why a migration is not possible.

[kderme]

plutusWhitelistCheck is called in plutusMaybeCheck, so why is it also called here?

[Cmdv]

I can't see plutusWhitelistCheck inside plutusMaybeCheck, am I understanding you right?

[kderme]

Oh sorry I got confused by indentation.

Actually I don't see what's the purpose of plutusMaybeCheck. It may return False even with PlutusEnable, which should never happen. plutusWhitelistCheck already does the necessary work.

[Cmdv]

The was my original comment

-- TODO: cmdv: unsure if this is correct because if plutusMaybeCheck fails then no multiasset whitelist is not checked

I was trying to make what we spoke about and push the checks as far up the chain and I may have miss understood what you meant and that's why I left this comment there about the plutusMaybeCheck. It's there as a check so you don't do any whitelist checks if there isn't any txOutScript or txOutAddress and that's what it was an && not an || so this is:

if plutusMaybeCheck txOuts
    then (plutusWhitelistCheck syncEnv txOuts || multiAssetWhitelistCheck syncEnv txOuts)
    else False

which is essentially bellow as it will return false straight away if plutusMaybeCheck txOuts if false:

plutusMaybeCheck txOuts && (plutusWhitelistCheck syncEnv txOuts || multiAssetWhitelistCheck syncEnv txOuts)

[kderme]

I still can't fully understand what does plutusMaybeCheck check, since all necessary checks are done in plutusWhitelistCheck. Using or instead of and here will simply give True in more cases than we want to.

[kderme]

I think we can just remove plutusMaybeCheck, unless I'm missing something

[Cmdv]

it was just to save doing big elem checks if they're not needed. But it's all good we can just do it inside the whitelist checks.

[Cmdv]

closing this PR as it's been superseded by #1644