Address PR feedback: handle negative width/height in bounds check

Author: merriemcgaw

src/System.Drawing.Common/src/System/Drawing/Graphics.cs

@@ -1226,10 +1226,29 @@ public void FillRectangle(Brush brush, float x, float y, float width, float heig
         // on a 24bppRgb bitmap, causing an AccessViolationException (or ExecutionEngineException in .NET 9+).
         // We validate the parameters here to prevent the crash.
         if (SmoothingMode == Drawing2D.SmoothingMode.AntiAlias &&
-            _backingImage is { PixelFormat: PixelFormat.Format24bppRgb } &&
-            (x < 0 || y < 0 || x + width > _backingImage.Width || y + height > _backingImage.Height))
+            _backingImage is { PixelFormat: PixelFormat.Format24bppRgb })
         {
-            throw new ArgumentException(SR.ArgumentException_GdiPlus_AntiAlias24bppRgbBounds);
+            float left = x;
+            float right = x + width;
+            float top = y;
+            float bottom = y + height;
+
+            if (width < 0)
+            {
+                left = right;
+                right = x;
+            }
+
+            if (height < 0)
+            {
+                top = bottom;
+                bottom = y;
+            }
+
+            if (left < 0 || top < 0 || right > _backingImage.Width || bottom > _backingImage.Height)
+            {
+                throw new ArgumentException(SR.ArgumentException_GdiPlus_AntiAlias24bppRgbBounds);
+            }
         }
 
         CheckErrorStatus(PInvokeGdiPlus.GdipFillRectangle(

src/System.Drawing.Common/tests/System/Drawing/GraphicsTests.cs

@@ -3009,6 +3009,8 @@ public void Graphics_FillRoundedRectangle_Float()
     [InlineData(10, -10, 100, 100)]        // Out of bounds (top)
     [InlineData(200, 10, 100, 100)]        // Out of bounds (right)
     [InlineData(10, 200, 100, 100)]        // Out of bounds (bottom)
+    [InlineData(10, 10, -100, 100)]        // Out of bounds (negative width extending left)
+    [InlineData(10, 10, 100, -100)]        // Out of bounds (negative height extending top)
     public void FillRectangle_AntiAlias_24bppRgb_OutOfBounds_ThrowsArgumentException(float x, float y, float width, float height)
     {
         using Bitmap bmp = new(256, 256, PixelFormat.Format24bppRgb);
@@ -3025,6 +3027,7 @@ public void FillRectangle_AntiAlias_24bppRgb_OutOfBounds_ThrowsArgumentException
     [Theory]
     [InlineData(0, 0, 100, 100)]           // Within bounds
     [InlineData(156, 156, 100, 100)]       // Exactly on bounds (256 - 100 = 156)
+    [InlineData(100, 100, -50, -50)]       // Within bounds (negative width/height)
     public void FillRectangle_AntiAlias_24bppRgb_WithinBounds_Success(float x, float y, float width, float height)
     {
         using Bitmap bmp = new(256, 256, PixelFormat.Format24bppRgb);