bug: proto3 default map key breaks deserialization

[conradhappeliv]

I have a proto3 map field with int32 keys:

message GameState {
    map<int32, PlayerData> player_data = 6;
}

This normally works, except when the map key is 0.

For example, this code is broken because from_bytes returns error REQUIRED_FIELDS:

var s = API.GameState.new()
s.add_player_data(0)
print(s.from_bytes(s.to_bytes()))  # Prints -9, aka "REQUIRED_FIELDS".

However, when I change the map key to something else (e.g. 1), deserialization works fine.

I assume this is due to improper handling of default values as map keys. I haven't tested it, but I assume the same issue is present for other default types (e.g. empty strings).

[oniksan]

Bug fixed in v 0.5.0