FIX: ControlScheme names with spaces treated as null (ISXB-547) (#1962)

A ControlScheme with only spaces is invalid and handled the same as a null/empty string: a default name is used instead.

Author: timkeo

Packages/com.unity.inputsystem/CHANGELOG.md

@@ -37,6 +37,7 @@ however, it has to be formatted properly to pass verification tests.
 - Fixed the UI generation of custom interactions of action properties when it rely on OnGUI callback. [ISXB-886](https://issuetracker.unity3d.com/product/unity/issues/guid/ISXB-886).
 - Fixed deletion of last composite part raising an exception. [ISXB-804](https://issuetracker.unity3d.com/product/unity/issues/guid/ISXB-804)
 - Fixed an issue related to Visualizers sample where exceptions would be thrown by InputActionVisualizer and InputControlVisualizer when entering play-mode if added as components to a new `GameObject`.
+- Fixed an issue with InputAction Asset editor where invalid ControlScheme names with only spaces could be entered. [ISXB-547](https://issuetracker.unity3d.com/product/unity/issues/guid/ISXB-547).
 
 ### Added
 - Added additional device information when logging the error due to exceeding the maximum number of events processed

Packages/com.unity.inputsystem/InputSystem/Editor/UITKAssetEditor/Commands/ControlSchemeCommands.cs

@@ -77,8 +77,8 @@ public static Command SaveControlScheme(string newControlSchemeName = "", bool u
                     RenameBindingsControlSchemeHelper(controlScheme, actionMaps, controlSchemeName, newControlSchemeName);
                 }
 
-                controlScheme.FindPropertyRelative(nameof(InputControlScheme.m_Name)).stringValue = string.IsNullOrEmpty(newControlSchemeName) ? controlSchemeName  : newControlSchemeName;
-                controlScheme.FindPropertyRelative(nameof(InputControlScheme.m_BindingGroup)).stringValue = string.IsNullOrEmpty(newControlSchemeName) ? controlSchemeName  : newControlSchemeName;
+                controlScheme.FindPropertyRelative(nameof(InputControlScheme.m_Name)).stringValue = string.IsNullOrWhiteSpace(newControlSchemeName) ? controlSchemeName  : newControlSchemeName;
+                controlScheme.FindPropertyRelative(nameof(InputControlScheme.m_BindingGroup)).stringValue = string.IsNullOrWhiteSpace(newControlSchemeName) ? controlSchemeName  : newControlSchemeName;
 
                 var serializedDeviceRequirements = controlScheme.FindPropertyRelative(nameof(InputControlScheme.m_DeviceRequirements));
                 serializedDeviceRequirements.ClearArray();