fix(lane_change): do not return empty path if no valid path (autowarefoundation#6686)

* fix(lane_change): do not return empty path if no valid path

Signed-off-by: Zulfaqar Azmi <zulfaqar.azmi@tier4.jp>

* style(pre-commit): autofix

---------

Signed-off-by: Zulfaqar Azmi <zulfaqar.azmi@tier4.jp>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

Author: 2 people

planning/behavior_path_lane_change_module/src/interface.cpp

@@ -99,10 +99,6 @@ BehaviorModuleOutput LaneChangeInterface::plan()
   resetPathCandidate();
   resetPathReference();
 
-  if (!module_type_->isValidPath()) {
-    return {};
-  }
-
   auto output = module_type_->generateOutput();
   path_reference_ = std::make_shared<PathWithLaneId>(output.reference_path);
   *prev_approved_path_ = getPreviousModuleOutput().path;

planning/behavior_path_lane_change_module/src/scene.cpp

@@ -197,6 +197,14 @@ BehaviorModuleOutput NormalLaneChange::generateOutput()
 {
   BehaviorModuleOutput output;
 
+  if (!status_.is_valid_path) {
+    output.path = prev_module_path_;
+    output.reference_path = prev_module_reference_path_;
+    output.drivable_area_info = prev_drivable_area_info_;
+    output.turn_signal_info = prev_turn_signal_info_;
+    return output;
+  }
+
   if (isAbortState() && abort_path_) {
     output.path = abort_path_->path;
     output.reference_path = prev_module_reference_path_;