deal with implicitly undeclared parameters

src/CameraNode.cpp

@@ -70,7 +70,7 @@ namespace camera
 class CameraNode : public rclcpp::Node
 {
 public:
-  explicit CameraNode(const rclcpp::NodeOptions &options);
+  explicit CameraNode(rclcpp::NodeOptions options);
 
   ~CameraNode();
 
@@ -187,8 +187,8 @@ compressImageMsg(const sensor_msgs::msg::Image &source,
 }
 
 
-CameraNode::CameraNode(const rclcpp::NodeOptions &options)
-    : Node("camera", options),
+CameraNode::CameraNode(rclcpp::NodeOptions options)
+    : Node("camera", options.allow_undeclared_parameters(true)),
       cim(this),
       parameter_handler(this),
       param_cb_change(

src/ParameterHandler.cpp

@@ -71,6 +71,11 @@ ParameterHandler::declare(const libcamera::ControlInfoMap &controls)
   // to unset them (set their type to 'rclcpp::ParameterType::PARAMETER_NOT_SET').
   // Unsetting a statically typed parameter causes "cannot undeclare a statically typed parameter".
 
+  // However, rclcpp::Node::set_parameter() implicitly undeclares a parameter if its type is
+  // set to rclcpp::PARAMETER_NOT_SET when it had a different type before.
+  // In order to re-set implicitly undeclared parameters, the node has to set
+  // "allow_undeclared_parameters".
+
   ParameterConflictHandler::ParameterValueMap parameters;
   for (const auto &[id, info] : controls) {
     // store control name with id and info