FIX: InputActionReference returning incorrect action when action has been called and cached, then Set and then calling action again.

Author: ekcoh

Assets/Tests/InputSystem/CoreTests_Actions.cs

@@ -11576,6 +11576,24 @@ public void Actions_CanResolveActionReference_EvenAfterActionHasBeenRenamed()
         Assert.That(referencedAction, Is.SameAs(action));
     }
 
+    [Test(Description = "https://issuetracker.unity3d.com/product/unity/issues/guid/ISXB-1584")]
+    [Category("Actions")]
+    public void Actions_CanResolveActionReferenceAndThenSetItToAnotherAction()
+    {
+        var map = new InputActionMap("map");
+        var action1 = map.AddAction("action1");
+        var action2 = map.AddAction("action2");
+        var asset = ScriptableObject.CreateInstance<InputActionAsset>();
+        asset.AddActionMap(map);
+
+        var reference = ScriptableObject.CreateInstance<InputActionReference>();
+        reference.Set(asset, "map", "action2");
+        Assert.That(reference.action, Is.SameAs(action2)); // Redundant, but important for test case
+
+        reference.Set(asset, "map", "action1");
+        Assert.That(reference.action, Is.SameAs(action1));
+    }
+
     [Test]
     [Category("Actions")]
     public void Actions_CanDisableAllEnabledActionsInOneGo()

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

@@ -136,6 +136,7 @@ private void SetInternal(InputActionAsset asset, InputAction action)
             m_Asset = asset;
             m_ActionId = action.id.ToString();
             name = GetDisplayName(action);
+            m_Action = action;
 
             ////REVIEW: should this dirty the asset if IDs had not been generated yet?
         }