IndexOutOfRangeException when repacking a multi-paged sprite atlas into a single-page sprite atlas

1. Import MetalMan texture into project
2. Set Sprite Mode to multiple and slice it in Sprite Editor
3. Right click -> Create -> Sprite Atlas
4. Change "Max Texture Size" of atlas to 512, select MetalMan to pack
5. Pack Preview
6. Select page 3 above the preview
7. Change "Max Texture Size" of atlas to 2048
8. Pack Preview

Expected: No errors, and the preview is correctly updated
Observed: IndexOutOfRangeException, and the preview is not updated

IndexOutOfRangeException: Array index is out of range.
UnityEditor.U2D.SpriteAtlasInspector.OnPreviewSettings () (at /Users/weswong/Work/trunk/unity/Editor/Mono/2D/SpriteAtlas/SpriteAtlasInspector.cs:394)
UnityEditor.InspectorWindow.DrawPreviewAndLabels () (at /Users/weswong/Work/trunk/unity/Editor/Mono/Inspector/InspectorWindow.cs:711)
UnityEditor.InspectorWindow.OnGUI () (at /Users/weswong/Work/trunk/unity/Editor/Mono/Inspector/InspectorWindow.cs:395)
System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) (at /Users/builduser/buildslave/mono/build/mcs/class/corlib/System.Reflection/MonoMethod.cs:222)

IndexOutOfRangeException: Array index is out of range.
UnityEditor.U2D.SpriteAtlasInspector.OnPreviewGUI (Rect r, UnityEngine.GUIStyle background) (at /Users/weswong/Work/trunk/unity/Editor/Mono/2D/SpriteAtlas/SpriteAtlasInspector.cs:414)
UnityEditor.Editor.OnHeaderIconGUI (Rect iconRect) (at /Users/weswong/Work/trunk/unity/Editor/Mono/Inspector/Editor.cs:419)
UnityEditor.Editor.DrawHeaderGUI (UnityEditor.Editor editor, System.String header, Single leftMargin) (at /Users/weswong/Work/trunk/unity/Editor/Mono/Inspector/Editor.cs:499)
UnityEditor.Editor.DrawHeaderGUI (UnityEditor.Editor editor, System.String header) (at /Users/weswong/Work/trunk/unity/Editor/Mono/Inspector/Editor.cs:465)
UnityEditor.Editor.OnHeaderGUI () (at /Users/weswong/Work/trunk/unity/Editor/Mono/Inspector/Editor.cs:361)
UnityEditor.Editor.DrawHeader () (at /Users/weswong/Work/trunk/unity/Editor/Mono/Inspector/Editor.cs:354)
UnityEditor.InspectorWindow.DrawEditor (UnityEditor.Editor editor, Int32 editorIndex, Boolean rebuildOptimizedGUIBlock, System.Boolean& showImportedObjectBarNext, UnityEngine.Rect& importedObjectBarRect) (at /Users/weswong/Work/trunk/unity/Editor/Mono/Inspector/InspectorWindow.cs:1094)
UnityEditor.InspectorWindow.DrawEditors (UnityEditor.Editor[] editors) (at /Users/weswong/Work/trunk/unity/Editor/Mono/Inspector/InspectorWindow.cs:1008)
UnityEditor.InspectorWindow.OnGUI () (at /Users/weswong/Work/trunk/unity/Editor/Mono/Inspector/InspectorWindow.cs:359)
System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) (at /Users/builduser/buildslave/mono/build/mcs/class/corlib/System.Reflection/MonoMethod.cs:222)

Occurring on: 2017.1.0a5 onwards