FIX: ISXB-687 Added guard clause to RemovePointerAtIndex in InputSy… (#1982)

* FIX: ISXB-687   Added guard clause to RemovePointerAtIndex in InputSystemUIInputModule to not remove touch pointers on the same frame they are released.

* Added changelog entry for fix ISXB-543

* Fixed infinite loop caused by FilterPointerStatesByType() trying to force their release on the same frame they occur.

Ran the formatter and applied changes to CHANGELOG.md

* Fixed issue where touch pointers don't get released when mouse or pen inputs happen.

* Fixed incorrect boolean logic in InputSystemUIInputModule.cs causing certain pointers to be incorrectly released or not released.

* Moved changelog entry for ISXB-687 into unreleased.

* Moved double touch pointer changelog entry to unreleased.

* Removed additional duplicate entries in changelog

* Removed superfluous code to get pointer state that is never used in InputSystemUIInputModule.

Author: adrian-koretski-unity3d

Packages/com.unity.inputsystem/CHANGELOG.md

@@ -11,6 +11,7 @@ however, it has to be formatted properly to pass verification tests.
 ## [Unreleased] - yyyy-mm-dd
 
 ### Fixed
+- Fixed touch pointers being released twice causing an index out of bounds error. [ISXB-687](https://issuetracker.unity3d.com/product/unity/issues/guid/ISXB-687)
 - Fixed `NullReferenceException` from disconnecting and reconnecting a GXDKGamepad.
 
 ### Added

Packages/com.unity.inputsystem/InputSystem/Plugins/UI/InputSystemUIInputModule.cs

@@ -1947,6 +1947,13 @@ private void RemovePointerAtIndex(int index)
         {
             Debug.Assert(m_PointerStates[index].eventData.pointerEnter == null, "Pointer should have exited all objects before being removed");
 
+            // We don't want to release touch pointers on the same frame they are released (unpressed). They get cleaned up one frame later in Process()
+            ref var state = ref GetPointerStateForIndex(index);
+            if (state.pointerType == UIPointerType.Touch && (state.leftButton.isPressed || state.leftButton.wasReleasedThisFrame))
+            {
+                return;
+            }
+
             // Retain event data so that we can reuse the event the next time we allocate a PointerModel record.
             var eventData = m_PointerStates[index].eventData;
             Debug.Assert(eventData != null, "Pointer state should have an event instance!");
@@ -2209,7 +2216,13 @@ private void FilterPointerStatesByType()
                     // We have input on a mouse or pen. Kill all touch and tracked pointers we may have.
                     for (var i = 0; i < m_PointerStates.length; ++i)
                     {
-                        if (m_PointerStates[i].pointerType != UIPointerType.MouseOrPen)
+                        ref var state = ref GetPointerStateForIndex(i);
+                        // Touch pointers need to get forced to no longer be pressed otherwise they will not get released in subsequent frames.
+                        if (m_PointerStates[i].pointerType == UIPointerType.Touch)
+                        {
+                            state.leftButton.isPressed = false;
+                        }
+                        if (m_PointerStates[i].pointerType != UIPointerType.MouseOrPen && m_PointerStates[i].pointerType != UIPointerType.Touch || (m_PointerStates[i].pointerType == UIPointerType.Touch && !state.leftButton.isPressed && !state.leftButton.wasReleasedThisFrame))
                         {
                             SendPointerExitEventsAndRemovePointer(i);
                             --i;