fix(behavior_path_planner): fix invalid access in avoidance module (#…

…4081)

Signed-off-by: tomoya.kimura <tomoya.kimura@tier4.jp>

planning/behavior_path_planner/src/scene_module/avoidance/avoidance_module.cpp

@@ -3045,7 +3045,7 @@ TurnSignalInfo AvoidanceModule::calcTurnSignalInfo(const ShiftedPath & path) con
   }
 
   // compute blinker start idx and end idx
-  const size_t blinker_start_idx = [&]() {
+  size_t blinker_start_idx = [&]() {
     for (size_t idx = start_idx; idx <= end_idx; ++idx) {
       const double current_shift_length = path.shift_length.at(idx);
       if (current_shift_length > 0.1) {
@@ -3054,7 +3054,13 @@ TurnSignalInfo AvoidanceModule::calcTurnSignalInfo(const ShiftedPath & path) con
     }
     return start_idx;
   }();
-  const size_t blinker_end_idx = end_idx;
+  size_t blinker_end_idx = end_idx;
+
+  // prevent invalid access for out-of-range
+  blinker_start_idx =
+    std::min(std::max(std::size_t(0), blinker_start_idx), path.path.points.size() - 1);
+  blinker_end_idx =
+    std::min(std::max(blinker_start_idx, blinker_end_idx), path.path.points.size() - 1);
 
   const auto blinker_start_pose = path.path.points.at(blinker_start_idx).point.pose;
   const auto blinker_end_pose = path.path.points.at(blinker_end_idx).point.pose;