Bug Quite bad bug where inputs without modifiers stop being read

Got a gnarly one with a simple reproduction.

If you create multiple commands, one for example for key w and one for ctrl+w, and then while reading the w input, disable the layer containing the commands, later when you re-enable the layer, the new input system won't respond to the command mapped to ctrl+w at all until the actions/devices are manually Reset()!

My guess is the internal tracking state likely becomes corrupt when disabled.

Though in the end the repro was simple, I struggled with this one for weeks trying to understand why some commands weren't working intermittently. Quite a nasty issue, and it's unclear if issuing Resets that frequently is causing additional issues.

Submitted a repro as case IN-42617; the simple code to repro below (alongside an event system with a new input system component)

1. Press ctrl+w you will see the "with modifier" command properly being read.

2. Press w and you will see "witohut modifier" command properly being read.

3. Press 2 to re-enable the input map.

4. ctrl+w no longer works!

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4. using UnityEngine.InputSystem;
5. using UnityEngine.UI;
6.  
7. public class Controller : MonoBehaviour
8. {
9.     InputActionMap map,map2;
10.  
11.     InputAction one,onen,sw1,sw2;
12.     void Start()
13.     {
14.         map = new InputActionMap();
15.         map2 = new InputActionMap();
16.  
17.  
18.         onen = map.AddAction("one", InputActionType.Button);
19.         onen.AddBinding("<Keyboard>/w");
20.         onen.AddBinding("<Gamepad>/buttonSouth");
21.  
22.         one = map.AddAction("one+ctrl", InputActionType.Button );
23.         one.AddCompositeBinding("OneModifier")
24.             .With("Binding", "<Keyboard>/w")
25.             .With("Modifier", "<Keyboard>/ctrl");
26.         one.AddCompositeBinding("OneModifier")
27.             .With("Binding", "<Gamepad>/buttonSouth")
28.             .With("Modifier", "<Gamepad>/leftTrigger");
29.  
30.         sw1 = map2.AddAction("sw1", InputActionType.Button);
31.         sw1.AddBinding("<Keyboard>/1");
32.         sw1.AddBinding("<Gamepad>/buttonWest");
33.  
34.         sw2 = map2.AddAction("sw2", InputActionType.Button);
35.         sw2.AddBinding("<Keyboard>/2");
36.         sw2.AddBinding("<Gamepad>/buttonNorth");
37.  
38.         map.Enable();
39.         map2.Enable();
40.     }
41.  
42.     // Update is called once per frame
43.     void Update()
44.     {
45.         if( sw1.WasPerformedThisFrame())
46.         {
47.             UnityEngine.Debug.Log("disable map");
48.             map.Disable();
49.         }
50.  
51.         if (sw2.WasPerformedThisFrame())
52.         {
53.             UnityEngine.Debug.Log("enable map");
54.             map.Enable();
55.         }
56.  
57.         if (one.WasPerformedThisFrame())
58.         {
59.             UnityEngine.Debug.Log("Action WITH MODIFIER (1) performed");
60.         }
61.  
62.         if (onen.WasPerformedThisFrame())
63.         {
64.             UnityEngine.Debug.Log("Action (1) performed");
65.             map.Disable(); // <--- Disabling it inside the update frame with this kind of rig seem to kill modifier tracking until the device/aciton is reset!
66.         }
67.     }
68.  
69. }
70.  

 

This was confirmed by QA case IN-42617/ISXB-505

This is an extremely critical bug, because while the sample above is contrived, the case where it triggers is pretty simple in practice:

1. press a button with a modifier that opens a new menu
2. the new menu switches up some layers (disabling one that was used to trigger it)
3. return to the previous menu or game view
4. quite a lot of controls are now permanently broken!