Add check if the sequence is optional, if it is not persent encode null 0x80 and false in the presence map.

Author: martinfantini

src/mfast/coder/encoder/fast_encoder.cpp

@@ -124,6 +124,16 @@ inline void fast_encoder_impl::visit(group_cref cref, int) {
 
 inline void fast_encoder_impl::visit(sequence_cref cref, int) {
 
+  if (cref.instruction()->optional() && !cref.present()) {
+    if (cref.instruction()->length_instruction()->pmap_size() > 0)
+      this->current_->set_next_bit(false);
+    if (cref.instruction()->length_instruction()->field_operator() != operator_constant &&
+        cref.instruction()->length_instruction()->field_operator() != operator_default &&
+        cref.instruction()->length_instruction()->field_operator() != operator_copy)
+      strm_.encode_null();
+    return;
+  }
+
   value_storage storage;
 
   uint32_mref length_mref(nullptr, &storage,

src/mfast/coder/encoder_v2/fast_encoder_core.h

@@ -259,6 +259,17 @@ inline void fast_encoder_core::encode_field(const T &ext_ref, group_type_tag) {
 template <typename T>
 inline void fast_encoder_core::encode_field(const T &ext_ref,
                                             sequence_type_tag) {
+
+  if (ext_ref.get().instruction()->optional() && !ext_ref.present()) {
+    if (T::length_type::has_pmap_type::value)
+      this->current_->set_next_bit(false);
+    if(!std::is_same<typename T::length_type::operator_category, constant_operator_tag>::value &&
+       !std::is_same<typename T::length_type::operator_category, copy_operator_tag>::value &&
+       !std::is_same<typename T::length_type::operator_category, default_operator_tag>::value )
+      strm_.encode_null();
+    return;
+  }
+
   value_storage storage;
 
   typename T::length_type length = ext_ref.get_length(storage);

src/mfast/ext_ref.h

@@ -167,6 +167,8 @@ class ext_cref<sequence_cref, LengthExtRef, ElementExtRef> {
   }
   std::size_t size() const { return base_.size(); }
 
+  bool present() const { return base_.present(); }
+
 private:
   sequence_cref base_;
 };