FIX: Fixed CallbackContext.ReadValue throwing when invoked during d…

Assets/Tests/InputSystem/CoreTests_Actions.cs

@@ -2802,6 +2802,46 @@ public void Actions_ControlsUpdateWhenDeviceIsRemoved()
         Assert.That(action.controls, Has.Count.Zero);
     }
 
+    [Test]
+    [Category("Actions")]
+    public void Actions_ActionListenerWillNotThrowWhenDeviceIsRemoved()
+    {
+        var gamepad = InputSystem.AddDevice<Gamepad>();
+
+        float triggerValue = 0.0f;
+        bool canceled = false;
+        bool performed = false;
+        var action = new InputAction();
+        action.AddBinding("<Gamepad>/leftTrigger");
+
+        action.canceled += ctx =>
+        {
+            canceled = true;
+            triggerValue = ctx.ReadValue<float>();
+        };
+
+        action.started += ctx =>
+        {
+            performed = true;
+            triggerValue = ctx.ReadValue<float>();
+        };
+        action.Enable();
+
+        InputSystem.QueueStateEvent(gamepad, new GamepadState {leftTrigger = 1.0f});
+        InputSystem.Update();
+
+        Assert.That(triggerValue, Is.EqualTo(1.0f));
+        Assert.That(performed, Is.True);
+        Assert.That(canceled, Is.False);
+        performed = false;
+
+        InputSystem.RemoveDevice(gamepad);
+
+        Assert.That(triggerValue, Is.EqualTo(0.0f));
+        Assert.That(performed, Is.False);
+        Assert.That(canceled, Is.True);
+    }
+
     [Test]
     [Category("Actions")]
     public void Actions_ControlsUpdateWhenDeviceIsRemoved_WhileActionIsDisabled()

Assets/Tests/InputSystem/CoreTests_Actions_Interactions.cs

@@ -4,6 +4,7 @@
 using UnityEngine.InputSystem.Interactions;
 using UnityEngine.InputSystem.LowLevel;
 using UnityEngine.InputSystem.Utilities;
+using UnityEngine.Scripting;
 
 internal partial class CoreTests
 {
@@ -485,4 +486,57 @@ public void Actions_CanCustomizeButtonPressPointsOfInteractions()
             Assert.That(trace, Started<HoldInteraction>(holdAction));
         }
     }
+
+    [Preserve]
+    private class CancelingTestInteraction : IInputInteraction
+    {
+        public void Process(ref InputInteractionContext context)
+        {
+            if (context.ControlIsActuated())
+            {
+                context.Performed();
+                context.Canceled();
+            }
+        }
+
+        public void Reset()
+        {
+        }
+    }
+
+    [Test]
+    [Category("Actions")]
+    public void Actions_ValueIsDefaultWhenActionIsCanceled()
+    {
+        InputSystem.RegisterInteraction<CancelingTestInteraction>();
+
+        var gamepad = InputSystem.AddDevice<Gamepad>();
+
+        var action = new InputAction("test", binding: "<Gamepad>/leftTrigger", interactions: "CancelingTest");
+        int performedCount = 0;
+        float performedValue = -1;
+        action.performed += ctx =>
+        {
+            performedValue = ctx.ReadValue<float>();
+            performedCount++;
+        };
+
+        int canceledCount = 0;
+        float canceledValue = -1;
+        action.canceled += ctx =>
+        {
+            canceledValue = ctx.ReadValue<float>();
+            canceledCount++;
+        };
+
+        action.Enable();
+
+        Set(gamepad.leftTrigger, 1.0f);
+
+        Assert.That(performedCount, Is.EqualTo(1));
+        Assert.That(performedValue, Is.EqualTo(1.0));
+
+        Assert.That(canceledCount, Is.EqualTo(1));
+        Assert.That(canceledValue, Is.EqualTo(0.0));
+    }
 }

Assets/Tests/InputSystem/Plugins/PlayerInputTests.cs

@@ -577,9 +577,8 @@ public void PlayerInput_CanAutoSwitchControlSchemesInSinglePlayer_WithDevicePlug
             Is.EquivalentTo(new[]
                 // This looks counter-intuitive but what happens is that when switching from gamepad1 to gamepad2,
                 // the system will first cancel ongoing actions. So it'll cancel "Move" which, given how PlayerInput
-                // sends messages, will simply come out as another "Move". And it's still bound to gamepad2's leftStick
-                // at that point, so the value we record is (0.234,0.345).
-            {new Message("OnMove", new StickDeadzoneProcessor().Process(new Vector2(0.234f, 0.345f))),
+                // sends messages, will simply come out as another "Move" with a zero value.
+            {new Message("OnMove", new StickDeadzoneProcessor().Process(new Vector2(0.0f, 0.0f))),
              new Message("OnMove", new StickDeadzoneProcessor().Process(new Vector2(0.345f, 0.456f)))}));
     }
 

Packages/com.unity.inputsystem/CHANGELOG.md

@@ -16,6 +16,7 @@ however, it has to be formatted properly to pass verification tests.
 
 #### Actions
 
+- Fixed `CallbackContext.ReadValue` throwing when invoked during device removal
 - Setting timeouts from `IInputInteraction.Process` not working as expected when processing happened in response to previous timeout expiring (#714).
 - Pending timeouts on a device not being removed when device was removed.
 

Packages/com.unity.inputsystem/InputSystem/Actions/InputAction.cs

@@ -865,7 +865,7 @@ public TValue ReadValue<TValue>()
                 where TValue : struct
             {
                 var value = default(TValue);
-                if (m_State != null)
+                if (m_State != null && phase != InputActionPhase.Canceled)
                     value = m_State.ReadValue<TValue>(bindingIndex, controlIndex);
                 return value;
             }

Packages/com.unity.inputsystem/InputSystem/Actions/InputActionState.cs

@@ -2008,7 +2008,6 @@ internal TValue ReadCompositePartValue<TValue>(int bindingIndex, int partNumber,
                     var value = ReadValue<TValue>(index, thisControlIndex, ignoreComposites: true);
 
                     ////REVIEW: not great that we do ButtonControl typechecks all the time even when they are not necessary
-
                     if (isFirstValue)
                     {
                         result = value;