Add span overloads to GraphicsPathIterator (dotnet#11594)

* Add span overloads to GraphicsPathIterator

Related to dotnet#8954.

This also adds more aggressive input validation to avoid buffer overruns.

* Validate end index is greater than or equal to start index.

src/System.Drawing.Common/src/CompatibilitySuppressions.xml

@@ -53,6 +53,20 @@
     <Right>lib/net8.0/System.Drawing.Common.dll</Right>
     <IsBaselineSuppression>true</IsBaselineSuppression>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0014</DiagnosticId>
+    <Target>T:System.Drawing.Drawing2D.GraphicsPathIterator:[T:System.Runtime.CompilerServices.NullableAttribute]</Target>
+    <Left>lib/net8.0/System.Drawing.Common.dll</Left>
+    <Right>lib/net8.0/System.Drawing.Common.dll</Right>
+    <IsBaselineSuppression>true</IsBaselineSuppression>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0014</DiagnosticId>
+    <Target>T:System.Drawing.Drawing2D.GraphicsPathIterator:[T:System.Runtime.CompilerServices.NullableContextAttribute]</Target>
+    <Left>lib/net8.0/System.Drawing.Common.dll</Left>
+    <Right>lib/net8.0/System.Drawing.Common.dll</Right>
+    <IsBaselineSuppression>true</IsBaselineSuppression>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0014</DiagnosticId>
     <Target>T:System.Drawing.Drawing2D.Matrix:[T:System.Runtime.CompilerServices.NullableAttribute]</Target>

src/System.Drawing.Common/src/System/Drawing/Drawing2D/GraphicsPathIterator.cs

@@ -147,13 +147,28 @@ public void Rewind()
         GC.KeepAlive(this);
     }
 
+    /// <inheritdoc cref="CopyData(ref PointF[], ref byte[], int, int)"/>
     public unsafe int Enumerate(ref PointF[] points, ref byte[] types)
+        => Enumerate(points.OrThrowIfNull().AsSpan(), types.OrThrowIfNull().AsSpan());
+
+    /// <inheritdoc cref="CopyData(ref PointF[], ref byte[], int, int)"/>
+#if NET9_0_OR_GREATER
+    public
+#else
+    private
+#endif
+    unsafe int Enumerate(Span<PointF> points, Span<byte> types)
     {
-        if (points.Length != types.Length)
+        if (points.Length != types.Length
+            || points.Length < Count)
+        {
             throw Status.InvalidParameter.GetException();
+        }
 
         if (points.Length == 0)
+        {
             return 0;
+        }
 
         fixed (PointF* p = points)
         fixed (byte* t = types)
@@ -171,10 +186,37 @@ public unsafe int Enumerate(ref PointF[] points, ref byte[] types)
         }
     }
 
+    /// <summary>
+    ///  Copies the <see cref="GraphicsPath.PathPoints"/> property and <see cref="GraphicsPath.PathTypes"/> property data
+    ///  of the associated <see cref="GraphicsPath"/>.
+    /// </summary>
+    /// <param name="points">Upon return, contains <see cref="PointF"/> structures that represent the points in the path.</param>
+    /// <param name="types">Upon return, contains bytes that represent the types of points in the path.</param>
+    /// <param name="startIndex">The index of the first point to copy.</param>
+    /// <param name="endIndex">The index of the last point to copy.</param>
+    /// <returns>The number of points copied.</returns>
     public unsafe int CopyData(ref PointF[] points, ref byte[] types, int startIndex, int endIndex)
+        => CopyData(points.OrThrowIfNull().AsSpan(), types.OrThrowIfNull().AsSpan(), startIndex, endIndex);
+
+    /// <inheritdoc cref="CopyData(ref PointF[], ref byte[], int, int)"/>
+#if NET9_0_OR_GREATER
+    public
+#else
+    private
+#endif
+    unsafe int CopyData(Span<PointF> points, Span<byte> types, int startIndex, int endIndex)
     {
-        if ((points.Length != types.Length) || (endIndex - startIndex + 1 > points.Length))
+        int count = endIndex - startIndex + 1;
+
+        if ((points.Length != types.Length)
+            || endIndex < 0
+            || startIndex < 0
+            || endIndex < startIndex
+            || count > points.Length
+            || endIndex >= Count)
+        {
             throw Status.InvalidParameter.GetException();
+        }
 
         fixed (PointF* p = points)
         fixed (byte* t = types)

src/System.Drawing.Common/tests/System/Drawing/Drawing2D/GraphicsPathIteratorTests.cs

@@ -264,6 +264,19 @@ public void Enumerate_PointsTypesMismatch_ThrowsArgumentException(PointF[] point
         AssertExtensions.Throws<ArgumentException>(null, () => gpi.Enumerate(ref points, ref types));
     }
 
+    [Fact]
+    public void Enumerate_NotEnoughSpace_ThrowsArgumentException()
+    {
+        using GraphicsPath gp = new();
+        gp.AddLine(new(0, 0), new(1, 1));
+        using GraphicsPathIterator gpi = new(gp);
+
+        PointF[] points = [];
+        byte[] types = [];
+
+        AssertExtensions.Throws<ArgumentException>(null, () => gpi.Enumerate(ref points, ref types));
+    }
+
     public static IEnumerable<object[]> NullPointsTypes_TestData()
     {
         yield return new object[] { null, new byte[1] };
@@ -273,11 +286,11 @@ public static IEnumerable<object[]> NullPointsTypes_TestData()
 
     [Theory]
     [MemberData(nameof(NullPointsTypes_TestData))]
-    public void Enumerate_NullPointsTypes_ThrowsNullReferenceException(PointF[] points, byte[] types)
+    public void Enumerate_NullPointsTypes_ThrowsArgumentNullException(PointF[] points, byte[] types)
     {
         using GraphicsPath gp = new();
         using GraphicsPathIterator gpi = new(gp);
-        Assert.Throws<NullReferenceException>(() => gpi.Enumerate(ref points, ref types));
+        Assert.Throws<ArgumentNullException>(() => gpi.Enumerate(ref points, ref types));
     }
 
     [Theory]
@@ -291,11 +304,11 @@ public void CopyData_PointsTypesMismatch_ThrowsArgumentException(PointF[] points
 
     [Theory]
     [MemberData(nameof(NullPointsTypes_TestData))]
-    public void CopyData_NullPointsTypes_ThrowsNullReferenceException(PointF[] points, byte[] types)
+    public void CopyData_NullPointsTypes_ThrowsArgumentNullException(PointF[] points, byte[] types)
     {
         using GraphicsPath gp = new();
         using GraphicsPathIterator gpi = new(gp);
-        Assert.Throws<NullReferenceException>(() => gpi.CopyData(ref points, ref types, 0, 1));
+        Assert.Throws<ArgumentNullException>(() => gpi.CopyData(ref points, ref types, 0, 1));
     }
 
     [Theory]
@@ -320,14 +333,14 @@ public static IEnumerable<object[]> CopyData_StartEndIndexesOutOfRange_TestData(
 
     [Theory]
     [MemberData(nameof(CopyData_StartEndIndexesOutOfRange_TestData))]
-    public void CopyData_StartEndIndexesOutOfRange_ReturnsExpected(PointF[] points, byte[] types, int startIndex, int endIndex)
+    public void CopyData_WithData_StartEndIndexesOutOfRange_ThrowsArgumentException(PointF[] points, byte[] types, int startIndex, int endIndex)
     {
         PointF[] resultPoints = new PointF[points.Length];
         byte[] resultTypes = new byte[points.Length];
 
         using GraphicsPath gp = new(points, types);
         using GraphicsPathIterator gpi = new(gp);
-        Assert.Equal(0, gpi.CopyData(ref resultPoints, ref resultTypes, startIndex, endIndex));
+        AssertExtensions.Throws<ArgumentException>(null, () => gpi.CopyData(ref resultPoints, ref resultTypes, startIndex, endIndex));
     }
 
     [Fact]