Enable nullability in ToolStripItemInternalLayout

src/System.Windows.Forms/src/System/Windows/Forms/ToolStripItem.ToolStripItemInternalLayout.ToolStripLayoutData.cs

@@ -23,7 +23,7 @@ public ToolStripLayoutData(ToolStrip toolStrip)
  _size = toolStrip.Size;
  }
 
- public bool IsCurrent(ToolStrip toolStrip)
+ public bool IsCurrent(ToolStrip? toolStrip)
  => toolStrip is not null && toolStrip.Size == _size && toolStrip.LayoutStyle == _layoutStyle && toolStrip.AutoSize == _autoSize;
  }
  }

src/System.Windows.Forms/src/System/Windows/Forms/ToolStripItem.ToolStripItemInternalLayout.cs

@@ -2,8 +2,6 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-#nullable disable
-
 using System.Drawing;
 using System.Windows.Forms.ButtonInternal;
 
@@ -16,14 +14,14 @@ public partial class ToolStripItem
  /// </summary>
  internal partial class ToolStripItemInternalLayout
  {
- private ToolStripItemLayoutOptions _currentLayoutOptions;
+ private ToolStripItemLayoutOptions? _currentLayoutOptions;
  private readonly ToolStripItem _ownerItem;
- private ButtonBaseAdapter.LayoutData _layoutData;
+ private ButtonBaseAdapter.LayoutData? _layoutData;
  private const int BorderWidth = 2;
  private readonly static Size s_invalidSize = new Size(int.MinValue, int.MinValue);
 
  private Size _lastPreferredSize = s_invalidSize;
- private ToolStripLayoutData _parentLayoutData;
+ private ToolStripLayoutData? _parentLayoutData;
 
  public ToolStripItemInternalLayout(ToolStripItem ownerItem)
  {
@@ -37,7 +35,7 @@ public virtual Rectangle ImageRectangle
  get
  {
  Rectangle imageRect = LayoutData.ImageBounds;
- imageRect.Intersect(_layoutData.Field);
+ imageRect.Intersect(_layoutData!.Field);
  return imageRect;
  }
  }
@@ -47,20 +45,20 @@ internal ButtonBaseAdapter.LayoutData LayoutData
  get
  {
  EnsureLayout();
- return _layoutData;
+ return _layoutData!;
  }
  }
 
  public Size PreferredImageSize => Owner.PreferredImageSize;
 
- protected virtual ToolStrip ParentInternal => _ownerItem?.ParentInternal;
+ protected virtual ToolStrip? ParentInternal => _ownerItem?.ParentInternal;
 
  public virtual Rectangle TextRectangle
  {
  get
  {
  Rectangle textRect = LayoutData.TextBounds;
- textRect.Intersect(_layoutData.Field);
+ textRect.Intersect(_layoutData!.Field);
  return textRect;
  }
  }
@@ -128,7 +126,7 @@ protected virtual ToolStripItemLayoutOptions CommonLayoutOptions()
  layoutOptions.GdiTextFormatFlags = ContentAlignToTextFormat(Owner.TextAlign, Owner.RightToLeft == RightToLeft.Yes);
 
  // Hide underlined &File unless ALT is pressed
- layoutOptions.GdiTextFormatFlags = (Owner.ShowKeyboardCues) ? layoutOptions.GdiTextFormatFlags : layoutOptions.GdiTextFormatFlags | TextFormatFlags.HidePrefix;
+ layoutOptions.GdiTextFormatFlags = Owner.ShowKeyboardCues ? layoutOptions.GdiTextFormatFlags : layoutOptions.GdiTextFormatFlags | TextFormatFlags.HidePrefix;
 
  return layoutOptions;
  }
@@ -159,7 +157,6 @@ private ButtonBaseAdapter.LayoutData GetLayoutData()
 
  public virtual Size GetPreferredSize(Size constrainingSize)
  {
- Size preferredSize = Size.Empty;
  EnsureLayout();
  // we would prefer not to be larger than the ToolStrip itself.
  // so we'll ask the ButtonAdapter layout guy what it thinks
@@ -169,7 +166,7 @@ public virtual Size GetPreferredSize(Size constrainingSize)
 
  if (_ownerItem is not null)
  {
- _lastPreferredSize = _currentLayoutOptions.GetPreferredSizeCore(constrainingSize);
+ _lastPreferredSize = _currentLayoutOptions!.GetPreferredSizeCore(constrainingSize);
  return _lastPreferredSize;
  }
 
@@ -179,7 +176,7 @@ public virtual Size GetPreferredSize(Size constrainingSize)
  internal void PerformLayout()
  {
  _layoutData = GetLayoutData();
- ToolStrip parent = ParentInternal;
+ ToolStrip? parent = ParentInternal;
  if (parent is not null)
  {
  _parentLayoutData = new ToolStripLayoutData(parent);