FIX: inactive touch driving invalid synthetic click on state reset

Assets/Tests/InputSystem/CoreTests_Actions.cs

@@ -1400,6 +1400,45 @@ public void Actions_ValueActionsEnabledInOnEvent_DoNotReactToCurrentStateOfContr
         }
     }
 
+    // Regression test for UUM-100125.
+    [Test]
+    [Category("Actions")]
+    public void Actions_InitialStateCheckAfterConfigurationChange_DoesNotTriggerForInactiveTouch()
+    {
+        var touchscreen = InputSystem.AddDevice<Touchscreen>();
+        var action = new InputAction(type: InputActionType.Value, binding: "<Touchscreen>/primaryTouch/position");
+        action.Enable();
+
+        // Run the first initial state check from enabling the action.
+        InputSystem.Update();
+
+        using (var trace = new InputActionTrace(action))
+        {
+            BeginTouch(1, new Vector2(123, 234));
+            EndTouch(1, new Vector2(345, 456));
+
+            Assert.That(touchscreen.primaryTouch.isInProgress, Is.False);
+            Assert.That(touchscreen.primaryTouch.position.ReadValue(), Is.Not.EqualTo(default(Vector2)));
+
+            trace.Clear();
+
+            // Configuration change causes full re-resolve and schedules initial state check.
+            InputSystem.QueueConfigChangeEvent(touchscreen);
+            InputSystem.Update();
+            InputSystem.Update();
+
+            // Full re-resolve may cancel the current action state. What must NOT happen is a synthetic
+            // Started/Performed pair from persisted inactive touch state.
+            Assert.AreEqual(1, trace.count);
+            foreach (var eventPtr in trace)
+            {
+                // The trace should only contain a Canceled event for the action.
+                Assert.AreEqual(InputActionPhase.Canceled, eventPtr.phase, 
+                    $"inactive touch state should not produce action callbacks, but received {eventPtr.phase}.");
+            }
+        }
+    }
+
     // https://fogbugz.unity3d.com/f/cases/1192972/
     [Test]
     [Category("Actions")]

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

@@ -1321,6 +1321,9 @@ private void OnBeforeInitialUpdate()
                     if (IsActiveControl(bindingIndex, controlIndex))
                         continue;
 
+                    if (ShouldSkipInitialStateCheck(control))
+                        continue;
+
                     if (!control.CheckStateIsAtDefault())
                     {
                         // Update press times.
@@ -1348,6 +1351,24 @@ private void OnBeforeInitialUpdate()
             k_InputInitialActionStateCheckMarker.End();
         }
 
+        private static bool ShouldSkipInitialStateCheck(InputControl control)
+        {
+            // UUM-100125
+            // Touch controls intentionally preserve state such as position even when no touch is currently active.
+            // During binding re-resolution this can make inactive touches look actuated and cause invalid triggers.
+            if (control is TouchControl touchControl)
+            {
+                return !touchControl.isInProgress;
+            }
+
+            if (control.parent is TouchControl parentTouchControl)
+            {
+                return !parentTouchControl.isInProgress;
+            }
+
+            return false;
+        }
+
         // Called from InputManager when one of our state change monitors has fired.
         // Tells us the time of the change *according to the state events coming in*.
         // Also tells us which control of the controls we are binding to triggered the