have a closer look at message decrypt vs pass phrase handling

[tomholub]

I have a concern about this particular original code, I'll have a second look later in a separate PR.

Originally posted by @tomholub in #3213 (comment)

[tomholub]

for completeness it's this code in getSortedKeys

// todo - the `ki.passphrase || ''` used to be `ki.passphrase!` which could have actually allowed an undefined to be passed
// as fixed currently it appears better, but it may be best to instead check `ki.passphrase && await MsgUtil.decryptKeyFor(...)`
// but that is a larger change that would require separate PR and testing
if (MsgUtil.isKeyDecryptedFor(parsed, matchingKeyids) || 
    await MsgUtil.decryptKeyFor(parsed, ki.passphrase || '', matchingKeyids) === true) {
  KeyCache.setDecrypted(parsed);
  keys.prvForDecryptDecrypted.push({ ki, decrypted: parsed });
} else {
  keys.prvForDecryptWithoutPassphrases.push(ki);
}

[tomholub]

I don't see any problem, other then what is already described in the comment. closing.