Do not reset user fonts in DataGridView

src/System.Windows.Forms.Primitives/tests/TestUtilities/Metafiles/EmfScope.cs

@@ -4,9 +4,9 @@
 
 #nullable enable
 
-using System.Collections.Generic;
 using System.Numerics;
 using System.Runtime.InteropServices;
+using System.Text;
 using static Interop;
 
 namespace System.Windows.Forms.Metafiles
@@ -167,29 +167,29 @@ bool stateTracker(ref EmfRecord record)
             }
         }
 
-        public List<string> RecordsToString()
+        public string RecordsToString()
         {
-            var strings = new List<string>();
+            StringBuilder sb = new StringBuilder(1024);
             Enumerate((ref EmfRecord record) =>
             {
-                strings.Add(record.ToString());
+                sb.AppendLine(record.ToString());
                 return true;
             });
 
-            return strings;
+            return sb.ToString();
         }
 
-        public List<string> RecordsToStringWithState(DeviceContextState state)
+        public string RecordsToStringWithState(DeviceContextState state)
         {
-            var strings = new List<string>();
+            StringBuilder sb = new StringBuilder(1024);
             EnumerateWithState((ref EmfRecord record, DeviceContextState state) =>
             {
-                strings.Add(record.ToString(state));
+                sb.AppendLine(record.ToString(state));
                 return true;
             },
             state);
 
-            return strings;
+            return sb.ToString();
         }
 
         private static unsafe BOOL CallBack(

src/System.Windows.Forms.Primitives/tests/TestUtilities/Metafiles/Validators/FontFaceNameValidator.cs

@@ -0,0 +1,20 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+#nullable enable
+
+using Xunit;
+
+namespace System.Windows.Forms.Metafiles
+{
+    internal class FontFaceNameValidator : IStateValidator
+    {
+        private readonly string _fontFaceName;
+
+        /// <param name="fontFaceName">The font face name to validate.</param>
+        public FontFaceNameValidator(string fontFaceName) => _fontFaceName = fontFaceName;
+
+        public void Validate(DeviceContextState state) => Assert.Equal(_fontFaceName, state.SelectedFont.FaceName.ToString());
+    }
+}

src/System.Windows.Forms.Primitives/tests/TestUtilities/Metafiles/Validators/State.cs

@@ -12,17 +12,18 @@ namespace System.Windows.Forms.Metafiles
 {
     internal static class State
     {
-        internal static IStateValidator TextColor(Color textColor) => new TextColorValidator(textColor);
+        internal static IStateValidator Brush(Color brushColor, Gdi32.BS brushStyle)
+            => new BrushValidator(brushColor, brushStyle);
+        internal static IStateValidator BrushColor(Color brushColor) => new BrushColorValidator(brushColor);
+        internal static IStateValidator BrushStyle(Gdi32.BS brushStyle) => new BrushStyleValidator(brushStyle);
+        internal static IStateValidator FontFace(string fontFaceName) => new FontFaceNameValidator(fontFaceName);
         internal static IStateValidator Pen(int penWidth, Color penColor, Gdi32.PS penStyle)
             => new PenValidator(penWidth, penColor, penStyle);
         internal static IStateValidator PenColor(Color penColor) => new PenColorValidator(penColor);
         internal static IStateValidator PenStyle(Gdi32.PS penStyle) => new PenStyleValidator(penStyle);
         internal static IStateValidator PenWidth(int penWidth) => new PenWidthValidator(penWidth);
-        internal static IStateValidator Brush(Color brushColor, Gdi32.BS brushStyle)
-            => new BrushValidator(brushColor, brushStyle);
-        internal static IStateValidator BrushColor(Color brushColor) => new BrushColorValidator(brushColor);
-        internal static IStateValidator BrushStyle(Gdi32.BS brushStyle) => new BrushStyleValidator(brushStyle);
         internal static IStateValidator Rop2(Gdi32.R2 rop2Mode) => new Rop2Validator(rop2Mode);
+        internal static IStateValidator TextColor(Color textColor) => new TextColorValidator(textColor);
         internal static IStateValidator Transform(Matrix3x2 transform) => new TransformValidator(transform);
     }
 }

src/System.Windows.Forms.Primitives/tests/TestUtilities/Metafiles/Validators/TextOutValidator.cs

@@ -13,21 +13,17 @@ namespace System.Windows.Forms.Metafiles
     internal sealed class TextOutValidator : StateValidator
     {
         private readonly string? _text;
-        private readonly string? _fontFace;
         private readonly Rectangle? _bounds;
 
         /// <param name="text">Optional text to validate.</param>
         /// <param name="bounds">Optional bounds to validate.</param>
-        /// <param name="fontFace">Optional font face name to validate.</param>
         /// <param name="stateValidators">Optional device context state validation to perform.</param>
         public TextOutValidator(
             string? text,
             Rectangle? bounds = default,
-            string? fontFace = default,
             params IStateValidator[] stateValidators) : base(stateValidators)
         {
             _text = text;
-            _fontFace = fontFace;
             _bounds = bounds;
         }
 
@@ -51,11 +47,6 @@ public override unsafe void Validate(ref EmfRecord record, DeviceContextState st
             {
                 Assert.Equal(_bounds.Value, (Rectangle)textOut->rclBounds);
             }
-
-            if (_fontFace != null)
-            {
-                Assert.Equal(_fontFace, state.SelectedFont.FaceName.ToString());
-            }
         }
     }
 }

src/System.Windows.Forms.Primitives/tests/TestUtilities/Metafiles/Validators/Validate.cs

@@ -35,16 +35,13 @@ internal static IEmfValidator Polyline16(
 
         /// <param name="text">Optional text to validate.</param>
         /// <param name="bounds">Optional bounds to validate.</param>
-        /// <param name="fontFace">Optional font face name to validate.</param>
         /// <param name="stateValidators">Optional device context state validation to perform.</param>
         internal static IEmfValidator TextOut(
             string? text = default,
             Rectangle? bounds = default,
-            string? fontFace = default,
             params IStateValidator[] stateValidators) => new TextOutValidator(
                 text,
                 bounds,
-                fontFace,
                 stateValidators);
 
         /// <param name="from">Optional source point to validate.</param>

src/System.Windows.Forms/src/System/Windows/Forms/DataGridView.cs

@@ -1612,6 +1612,10 @@ public DataGridViewCellStyle ColumnHeadersDefaultCellStyle
                 {
                     _columnHeadersDefaultCellStyle.AddScope(this, DataGridViewCellStyleScopes.ColumnHeaders);
                 }
+
+                // Update ambient font flag depending on cell style font
+                _dataGridViewState1[State1_AmbientColumnHeadersFont] = value?.Font == base.Font;
+
                 DataGridViewCellStyleDifferences dgvcsc = cs.GetDifferencesFrom(ColumnHeadersDefaultCellStyle);
                 if (dgvcsc != DataGridViewCellStyleDifferences.None)
                 {
@@ -2128,6 +2132,10 @@ _defaultCellStyle.Font is null ||
                 {
                     _defaultCellStyle.AddScope(this, DataGridViewCellStyleScopes.DataGridView);
                 }
+
+                // Update ambient font flag depending on cell style font
+                _dataGridViewState1[State1_AmbientFont] = value?.Font == base.Font;
+
                 DataGridViewCellStyleDifferences dgvcsc = cs.GetDifferencesFrom(DefaultCellStyle);
                 if (dgvcsc != DataGridViewCellStyleDifferences.None)
                 {
@@ -3577,6 +3585,10 @@ public DataGridViewCellStyle RowHeadersDefaultCellStyle
                 {
                     _rowHeadersDefaultCellStyle.AddScope(this, DataGridViewCellStyleScopes.RowHeaders);
                 }
+
+                // Update ambient font flag depending on cell style font
+                _dataGridViewState1[State1_AmbientRowHeadersFont] = value?.Font == base.Font;
+
                 DataGridViewCellStyleDifferences dgvcsc = cs.GetDifferencesFrom(RowHeadersDefaultCellStyle);
                 if (dgvcsc != DataGridViewCellStyleDifferences.None)
                 {