melt returns empty preimage for quotes that can be settled internally

[elnosh]

created a mint and melt quote pair with the same invoice and when tried melting in /v1/melt/bolt11, it returned the state as paid but the preimage field was empty.

[callebtc]

Preimage can't be returned internally (not available)

[callebtc]

Is it possible after all?

[elnosh]

not sure for all backends but with LND you could get the preimage from the invoice created in the mint quote request from LookupInvoice call https://lightning.engineering/api-docs/api/lnd/lightning/lookup-invoice/index.html