Bug: If top-level struct is registered, every field will be treated as registered

[liamsi]

The macro-generated code always checks the top-level attributes of the wrapping message for is_registered instead of on a per field basis :-/

We haven't noticed that so far because the only place this feature was (successfully) used was for PubKeyMsg which contains only one field which also happen to be registered.

amino_rs/prost-amino-derive/src/lib.rs

Lines 276 to 281 in 06d64fa

	if #is_registered {
	// skip some bytes: varint(total_len) || prefix_bytes
	// prefix (4) + total_encoded_len:
	let _full_len = _prost::encoding::decode_varint(buf)?;
	buf.advance(4);
	}

amino_rs/prost-amino-derive/src/lib.rs

Lines 34 to 42 in 06d64fa

	let top_level_attrs: Vec<syn::Attribute> = input.attrs;
	let amino_name_attrs: Vec<syn::Attribute> = top_level_attrs
	.into_iter()
	.filter(|a| a.path.segments.first().unwrap().value().ident == "amino_name")
	.collect();
	if amino_name_attrs.len() > 1 {
	bail!("got more than one registered amino_name");
	}
	let is_registered = amino_name_attrs.len() == 1;

Additionally, this length computation is wrong:

amino_rs/prost-amino-derive/src/lib.rs

Lines 260 to 264 in 06d64fa

	if #is_registered {
	// TODO: in go-amino this only get length-prefixed if MarhsalBinary is used
	// opposed to MarshalBinaryBare
	let len = 4 #(+ #encoded_len2)*;
	_prost::encoding::encode_varint(len as u64, buf);

[liamsi]

ref: https://github.com/tendermint/amino_rs/tree/debugging_issue28