[Bug]: Error Code: LeafAuthorityMustSign when using mpl_bubblegum crate to transfer or burn compressed NFT

[ZYJLiu]

Which package is this bug report for?

bubblegum

Which Type of Package is this bug report for?

mpl_bubblegum crate

Issue description

When using the mpl_bubblegum crate to invoke the transfer or burn instruction on the bubblegum program, the CPI fails with LeafAuthorityMustSign.

Here is a minimal Anchor program to reproduce the issue.
https://github.com/ZYJLiu/anchor-cnft-transfer

It contains two instructions:

• transfer_one: manually builds the CPI to invoke the bubblegum transfer instruction, which works successfully
• transfer_two: uses the mpl_bubblegum crate to invoke the bubblegum transfer instruction, which fails with LeafAuthorityMustSign error

There is a .env.example file that should be renamed .env which requires a Helius API key to fetch the asset and asset proof to use in the test.

May require downgrading to solana 1.14 for test to run.
solana-install init 1.14.18

Relevant log output

Error: AnchorError thrown in src/lib.rs:1209. Error Code: LeafAuthorityMustSign. Error Number: 6025. Error Message: This transaction must be signed by either the leaf owner or leaf delegate.

Priority this issue should have

High (immediate attention needed)

[samuelvanderwaal]

Thanks for including a reproducible example in this report--that makes debugging significantly easier. Unfortunately, this is a limitation/bug/known issue with Anchor and using multipl UncheckedAccounts that are optional signers: see this issue coral-xyz/anchor#1899. There may be a way to fix this by creating a transfer_v2 with a different account structure, but otherwise I don't think we can fix transfer without a breaking change, so you'll need to use the manual cpi invoke method for now, sorry!