fix(behavior_path_planner): return default value if no registered mod…

…ule exists (autowarefoundation#3843) (#541)

Signed-off-by: satoshi-ota <satoshi.ota928@gmail.com>
Co-authored-by: Satoshi OTA <44889564+satoshi-ota@users.noreply.github.com>

planning/behavior_path_planner/include/behavior_path_planner/scene_module/scene_module_manager_interface.hpp

@@ -205,6 +205,10 @@ class SceneModuleManagerInterface
 
   bool isSimultaneousExecutableAsApprovedModule() const
   {
+    if (registered_modules_.empty()) {
+      return enable_simultaneous_execution_as_approved_module_;
+    }
+
     return std::all_of(
       registered_modules_.begin(), registered_modules_.end(), [](const SceneModulePtr & module) {
         return module->isSimultaneousExecutableAsApprovedModule();
@@ -213,6 +217,10 @@ class SceneModuleManagerInterface
 
   bool isSimultaneousExecutableAsCandidateModule() const
   {
+    if (registered_modules_.empty()) {
+      return enable_simultaneous_execution_as_candidate_module_;
+    }
+
     return std::all_of(
       registered_modules_.begin(), registered_modules_.end(), [](const SceneModulePtr & module) {
         return module->isSimultaneousExecutableAsCandidateModule();