FIX: Not adding temp settings object to preloaded assets, and actually setting dirty flag so editor saves asset on exit (#1590)

Author: Dmytro Ivanov

Packages/com.unity.inputsystem/CHANGELOG.md

@@ -12,6 +12,7 @@ however, it has to be formatted properly to pass verification tests.
 
 ### Fixed
 - Fixed `ArgumentNullException` when opening the Prefab Overrides window and selecting a component with an `InputAction`.
+- Fixed `{fileID: 0}` getting appended to `ProjectSettings.asset` file when building a project ([case ISXB-296](https://issuetracker.unity3d.com/product/unity/issues/guid/ISXB-296)).
 
 ## [1.4.3] - 2022-09-23
 

Packages/com.unity.inputsystem/InputSystem/Editor/Settings/InputSettingsBuildProvider.cs

@@ -9,65 +9,43 @@ namespace UnityEngine.InputSystem.Editor
 {
     internal class InputSettingsBuildProvider : IPreprocessBuildWithReport, IPostprocessBuildWithReport
     {
-        private InputSettings m_SettingsAddedToPreloadedAssets;
-
         public int callbackOrder => 0;
 
         public void OnPreprocessBuild(BuildReport report)
         {
             if (InputSystem.settings == null)
                 return;
 
-            var wasDirty = IsPlayerSettingsDirty();
-            m_SettingsAddedToPreloadedAssets = null;
+            // If we operate on temporary object instead of input setting asset,
+            // adding temporary asset would result in preloadedAssets containing null object "{fileID: 0}".
+            // Hence we ignore adding temporary objects to preloaded assets.
+            if (!EditorUtility.IsPersistent(InputSystem.settings))
+                return;
 
             // Add InputSettings object assets, if it's not in there already.
             var preloadedAssets = PlayerSettings.GetPreloadedAssets();
             if (!preloadedAssets.Contains(InputSystem.settings))
             {
-                m_SettingsAddedToPreloadedAssets = InputSystem.settings;
-                ArrayHelpers.Append(ref preloadedAssets, m_SettingsAddedToPreloadedAssets);
+                ArrayHelpers.Append(ref preloadedAssets, InputSystem.settings);
                 PlayerSettings.SetPreloadedAssets(preloadedAssets);
             }
-
-            if (!wasDirty)
-                ClearPlayerSettingsDirtyFlag();
         }
 
         public void OnPostprocessBuild(BuildReport report)
         {
-            if (m_SettingsAddedToPreloadedAssets == null)
-                return;
-
-            var wasDirty = IsPlayerSettingsDirty();
-
-            // Revert back to original state.
+            // Revert back to original state by removing all input settings from preloaded assets.
             var preloadedAssets = PlayerSettings.GetPreloadedAssets();
-            var index = preloadedAssets.IndexOfReference<Object, Object>(m_SettingsAddedToPreloadedAssets);
-            if (index != -1)
+            while (preloadedAssets != null && preloadedAssets.Length > 0)
             {
-                ArrayHelpers.EraseAt(ref preloadedAssets, index);
-                PlayerSettings.SetPreloadedAssets(preloadedAssets);
+                var index = preloadedAssets.IndexOf(x => x is InputSettings);
+                if (index != -1)
+                {
+                    ArrayHelpers.EraseAt(ref preloadedAssets, index);
+                    PlayerSettings.SetPreloadedAssets(preloadedAssets);
+                }
+                else
+                    break;
             }
-            m_SettingsAddedToPreloadedAssets = null;
-
-            if (!wasDirty)
-                ClearPlayerSettingsDirtyFlag();
-        }
-
-        private static bool IsPlayerSettingsDirty()
-        {
-            var settings = Resources.FindObjectsOfTypeAll<PlayerSettings>();
-            if (settings != null && settings.Length > 0)
-                return EditorUtility.IsDirty(settings[0]);
-            return false;
-        }
-
-        private static void ClearPlayerSettingsDirtyFlag()
-        {
-            var settings = Resources.FindObjectsOfTypeAll<PlayerSettings>();
-            if (settings != null && settings.Length > 0)
-                EditorUtility.ClearDirty(settings[0]);
         }
     }
 }