[parser] register if a micheline is the unit value

app/src/parser/micheline_parser.c

@@ -47,6 +47,7 @@ tz_micheline_parser_init(tz_parser_state *state)
 
     m->frame         = m->stack;
     m->stack[0].step = TZ_MICHELINE_STEP_TAG;
+    m->is_unit       = false;
 }
 
 /**
@@ -373,6 +374,12 @@ tz_micheline_parser_step(tz_parser_state *state)
         }
         m->frame->step         = TZ_MICHELINE_STEP_PRIM_NAME;
         m->frame->step_prim.op = op;
+        // clang-format off
+        m->is_unit = ((m->frame == m->stack)
+                      && (op == TZ_MICHELSON_OP_Unit)
+                      && (m->frame->step_prim.nargs == 0)
+                      && (!m->frame->step_prim.annot));
+        // clang-format on
         break;
     case TZ_MICHELINE_STEP_PRIM_NAME:
         if (m->frame->step_prim.wrap && m->frame->step_prim.first) {

app/src/parser/micheline_state.h

@@ -129,4 +129,5 @@ typedef struct {
         stack[TZ_MICHELINE_STACK_DEPTH];  /// stack of frames
     tz_micheline_parser_frame *frame;     /// current frame
                                           /// init == stack, NULL when done
+    bool is_unit;  /// indicates whether the micheline read is a unit
 } tz_micheline_state;

app/src/parser/operation_parser.c

@@ -573,6 +573,9 @@ tz_step_read_micheline(tz_parser_state *state)
     }
     tz_micheline_parser_step(state);
     if (state->errno == TZ_BLO_DONE) {
+        if (state->micheline.is_unit) {
+            state->field_info.is_field_complex = false;
+        }
         if ((op->frame->stop != 0) && (state->ofs != op->frame->stop)) {
             tz_raise(TOO_LARGE);
         }

tests/unit/ctest/tests_parser.c

@@ -304,7 +304,7 @@ CTEST2(operation_parser, check_stake_complexity)
  //     {"Option",        _,     6},
   //    {"Tuple",         _,     7},
         {"Entrypoint",    false, 8},
-        {"Parameter",     true,  9},
+        {"Parameter",     false, 9},
     };
     check_field_complexity(data, str, fields_check, sizeof(fields_check));
 }
@@ -324,7 +324,7 @@ CTEST2(operation_parser, check_unstake_complexity)
  //     {"Option",        _,     6},
   //    {"Tuple",         _,     7},
         {"Entrypoint",    false, 8},
-        {"Parameter",     true,  9},
+        {"Parameter",     false, 9},
     };
     check_field_complexity(data, str, fields_check, sizeof(fields_check));
 }
@@ -344,7 +344,7 @@ CTEST2(operation_parser, check_finalize_unstake_complexity)
  //     {"Option",        _,     6},
   //    {"Tuple",         _,     7},
         {"Entrypoint",    false, 8},
-        {"Parameter",     true,  9},
+        {"Parameter",     false, 9},
     };
     check_field_complexity(data, str, fields_check, sizeof(fields_check));
 }