message: Avoid subscripting errors when processing empty json arrays
diff: @@ -314,6 +314,7 @@ namespace eosio { namespace chain { namespace contracts {
  }
  */
  uint32_t i = 0;
  + if (va.size() > 0) {
  for( const auto& field : st.fields ) {
  idump((field.type)(va[i])(i));
  if( va.size() > i )
  @@ -324,6 +325,7 @@ namespace eosio { namespace chain { namespace contracts {
  }
  }
  }
  + }
  } FC_CAPTURE_AND_RETHROW( (type)(var) ) }
  bytes abi_serializer::variant_to_binary(const type_name& type, const fc::variant& var)const { try {
  