Fix serial import/export for variant

m-serial-json.h

@@ -378,7 +378,7 @@ m_serial_json_read_variant_end(m_serial_read_t serial)
   FILE *f = (FILE*) serial->data[0];
   int final = -1;
   fscanf(f, " }%n", &final);
-  return final > 0 ? M_SERIAL_OK_CONTINUE : M_SERIAL_FAIL;
+  return final > 0 ? M_SERIAL_OK_DONE : M_SERIAL_FAIL;
 }
 
 static const m_serial_read_interface_t m_serial_json_read_interface = {

m-variant.h

@@ -551,7 +551,7 @@
       M_MAP2(VARIANTI_DEFINE_IN_SERIAL_FUNC , name, __VA_ARGS__)        \
     default: assert(false); break;                                      \
     }                                                                   \
-    if (ret != M_SERIAL_OK_DONE)                                        \
+    if (ret == M_SERIAL_OK_DONE)                                        \
       ret = f->interface->read_variant_end(f);                          \
     return ret;                                                         \
   }
@@ -584,6 +584,8 @@
    M_IF_METHOD2_ALL(PARSE_STR, INIT, __VA_ARGS__)(PARSE_STR(M_C(name, _parse_str)),), \
    M_IF_METHOD2_ALL(IN_STR, INIT, __VA_ARGS__)(IN_STR(M_C(name, _in_str)),), \
    M_IF_METHOD_ALL(OUT_STR, __VA_ARGS__)(OUT_STR(M_C(name, _out_str)),), \
+   M_IF_METHOD2_ALL(IN_SERIAL, INIT, __VA_ARGS__)(IN_SERIAL(M_C(name, _in_serial)),), \
+   M_IF_METHOD_ALL(OUT_SERIAL, __VA_ARGS__)(OUT_SERIAL(M_C(name, _out_serial)),), \
    M_IF_METHOD_ALL(INIT_MOVE, __VA_ARGS__)(INIT_MOVE(M_C(name, _init_move)),), \
    M_IF_METHOD_ALL(INIT_MOVE, __VA_ARGS__)(MOVE(M_C(name, _move)),),    \
    M_IF_METHOD_ALL(SWAP, __VA_ARGS__)(SWAP(M_C(name, _swap)),),         \