fix docstring and remove redundant argument

Signed-off-by: Zulfaqar Azmi <[email protected]>

planning/behavior_path_planner/autoware_behavior_path_lane_change_module/include/autoware/behavior_path_lane_change_module/utils/path.hpp

@@ -32,7 +32,7 @@ using behavior_path_planner::lane_change::CommonDataPtr;
  *
  * This function generates the "prepare segment" of the path by trimming it to the specified length,
  * adjusting longitudinal velocity for acceleration or deceleration, and ensuring the starting point
- * meets necessary constraints for a lane change. the ego vehicle for a lane change. It adjusts the
+ * meets necessary constraints for a lane change.
  *
  * @param common_data_ptr Shared pointer to CommonData containing current and target lane
  *                        information, vehicle parameters, and ego state.
@@ -75,8 +75,7 @@ bool get_prepare_segment(
 LaneChangePath get_candidate_path(
   const CommonDataPtr & common_data_ptr, const LaneChangePhaseMetrics & prep_metric,
   const LaneChangePhaseMetrics & lc_metric, const PathWithLaneId & prep_segment,
-  const std::vector<std::vector<int64_t>> & sorted_lane_ids, const Pose & lc_start_pose,
-  const double shift_length);
+  const std::vector<std::vector<int64_t>> & sorted_lane_ids, const double shift_length);
 
 /**
  * @brief Constructs a candidate path for a lane change maneuver.

planning/behavior_path_planner/autoware_behavior_path_lane_change_module/src/scene.cpp

@@ -1160,8 +1160,7 @@ bool NormalLaneChange::get_lane_change_paths(LaneChangePaths & candidate_paths)
       LaneChangePath candidate_path;
       try {
         candidate_path = utils::lane_change::get_candidate_path(
-          common_data_ptr_, prep_metric, lc_metric, prepare_segment, sorted_lane_ids,
-          lane_changing_start_pose, shift_length);
+          common_data_ptr_, prep_metric, lc_metric, prepare_segment, sorted_lane_ids, shift_length);
       } catch (const std::exception & e) {
         debug_print_lat(std::string("Reject: ") + e.what());
         continue;

planning/behavior_path_planner/autoware_behavior_path_lane_change_module/src/utils/path.cpp

@@ -206,18 +206,23 @@ bool get_prepare_segment(
 LaneChangePath get_candidate_path(
   const CommonDataPtr & common_data_ptr, const LaneChangePhaseMetrics & prep_metric,
   const LaneChangePhaseMetrics & lc_metric, const PathWithLaneId & prep_segment,
-  const std::vector<std::vector<int64_t>> & sorted_lane_ids, const Pose & lc_start_pose,
-  const double shift_length)
+  const std::vector<std::vector<int64_t>> & sorted_lane_ids, const double shift_length)
 {
   const auto & route_handler = *common_data_ptr->route_handler_ptr;
   const auto & target_lanes = common_data_ptr->lanes_ptr->target;
 
   const auto resample_interval = calc_resample_interval(lc_metric.length, prep_metric.velocity);
+
+  if (prep_segment.points.empty()) {
+    throw std::logic_error("Empty prepare segment!");
+  }
+
+  const auto & lc_start_pose = prep_segment.points.back().point.pose;
   const auto target_lane_reference_path = get_reference_path_from_target_Lane(
     common_data_ptr, lc_start_pose, lc_metric.length, resample_interval);
 
   if (target_lane_reference_path.points.empty()) {
-    throw std::logic_error("target_lane_reference_path is empty!");
+    throw std::logic_error("Empty target reference!");
   }
 
   const auto lc_end_pose = std::invoke([&]() {