Empty input action result in NRE in InputActionsRecorderModule

[ahmed-shariff]

With the XR HMD and input system configured, I was getting the following error:

NullReferenceException: Object reference not set to an instance of an object
PLUME.Base.Module.Unity.Input.InputActionsRecorderModule.OnActionPerformed (UnityEngine.InputSystem.InputAction+CallbackContext context) (at ./Packages/PLUME-Recorder/Runtime/Base/Module/Unity/Input/InputActionsRecorderModule.cs:58)
UnityEngine.InputSystem.Utilities.DelegateHelpers.InvokeCallbacksSafe[TValue] (UnityEngine.InputSystem.Utilities.CallbackArray`1[System.Action`1[TValue]]& callbacks, TValue argument, System.String callbackName, System.Object context) (at ./Library/PackageCache/com.unity.inputsystem@be6c4fd0abf5/InputSystem/Utilities/DelegateHelpers.cs:46)
UnityEngine.InputSystem.LowLevel.<>c__DisplayClass7_0:<set_onUpdate>b__0(NativeInputUpdateType, NativeInputEventBuffer*)
UnityEngineInternal.Input.NativeInputSystem:NotifyUpdate(NativeInputUpdateType, IntPtr)

and

NullReferenceException while executing 'performed' callbacks of 'Main Camera (XR) - TPD - Position[/HeadTrackingOpenXR/centereyeposition]'
UnityEngine.InputSystem.LowLevel.NativeInputRuntime/<>c__DisplayClass7_0:<set_onUpdate>b__0 (UnityEngineInternal.Input.NativeInputUpdateType,UnityEngineInternal.Input.NativeInputEventBuffer*)
UnityEngineInternal.Input.NativeInputSystem:NotifyUpdate (UnityEngineInternal.Input.NativeInputUpdateType,intptr)
UnityEngine.GUIUtility:ProcessEvent (int,intptr,bool&)

Seems to be happening with the following actions:

• Main Camera (XR) - TPD - Tracking State[/HeadTrackingOpenXR/trackingstate]
• Main Camera (XR) - TPD - Position[/HeadTrackingOpenXR/centereyeposition]
• Main Camera (XR) - TPD - Rotation[/HeadTrackingOpenXR/centereyerotation]

[ahmed-shariff]

I couldn't figure out what was causing this all of a sudden. For now I have the following patch in InputActionsRecorderModule:

@@ -49,9 +49,53 @@ namespace PLUME.Base.Module.Unity.Input
             if (!_ctx.IsRecording)
                 return;
 
+            var action = context.action;
+            if (action == null)
+            {
+                Debug.LogWarning("OnActionPerformed: context.action is null");
+
+                var emptyInputActionSample = new Sample.Unity.InputAction
+                {
+                    Name = "(EmptyAction)"
+                };
+                emptyInputActionSample.Type = Sample.Unity.InputActionType.Value;
+                _ctx.CurrentRecord.RecordTimestampedManagedSample(emptyInputActionSample);
+                return;
+            }
+
+            // Get map name safely
+            string mapName;
+            var map = action.actionMap;
+            if (map == null)
+            {
+                mapName = "(NoActionMap)";
+            }
+            else
+            {
+                if (map.name == null || map.name.Length == 0)
+                {
+                    mapName = "(UnnamedActionMap)";
+                }
+                else
+                {
+                    mapName = map.name;
+                }
+            }
+
+            // Get action name safely
+            string actionName;
+            if (action.name == null || action.name.Length == 0)
+            {
+                actionName = "(UnnamedAction)";
+            }
+            else
+            {
+                actionName = action.name;
+            }
+
             var inputActionSample = new Sample.Unity.InputAction
             {
-                Name = context.action.actionMap.name + '/' + context.action.name
+                Name = mapName + '/' + actionName
             };
             inputActionSample.BindingPaths.AddRange(context.action.bindings.Select(b => b.path));