Fix for icons

Author: yaira2

src/Files.App.Storage/Storables/WindowsStorage/WindowsStorableHelpers.Icon.cs

@@ -20,6 +20,32 @@ public static partial class WindowsStorableHelpers
 		private static (Guid Format, Guid Encorder)[]? GdiEncoders;
 		private static ConcurrentDictionary<(string, int, int), byte[]>? DllIconCache;
 
+		private const int PixelFormat32bppARGB = 2498570; // Added constant for transparency
+
+		[StructLayout(LayoutKind.Sequential)]
+		private struct BITMAP // Added BITMAP structure for bitmap operations
+		{
+			public int bmType;
+			public int bmWidth;
+			public int bmHeight;
+			public int bmWidthBytes;
+			public ushort bmPlanes;
+			public ushort bmBitsPixel;
+			public IntPtr bmBits;
+		}
+
+		[DllImport("gdi32.dll", SetLastError = true)] // Added P/Invoke for GetObject
+		private static extern int GetObject(IntPtr hObject, int nCount, ref BITMAP lpObject);
+
+		[DllImport("gdiplus.dll", SetLastError = true)] // Added P/Invoke for GdipCreateBitmapFromScan0
+		private static extern int GdipCreateBitmapFromScan0(
+			int width,
+			int height,
+			int stride,
+			int pixelFormat,
+			IntPtr scan0,
+			out IntPtr bitmap);
+
 		// Methods
 
 		/// <inheritdoc cref="TryGetThumbnail"/>
@@ -57,15 +83,43 @@ public unsafe static HRESULT TryGetThumbnail(this IWindowsStorable storable, int
 				return hr;
 			}
 
-			// Convert to GpBitmap of GDI+
-			GpBitmap* gpBitmap = default;
-			if (PInvoke.GdipCreateBitmapFromHBITMAP(hBitmap, HPALETTE.Null, &gpBitmap) is not Status.Ok)
+			// Retrieve BITMAP data
+			BITMAP bmp = new BITMAP();
+			if (GetObject((nint)hBitmap.Value, Marshal.SizeOf(typeof(BITMAP)), ref bmp) == 0)
 			{
-				if (gpBitmap is not null) PInvoke.GdipDisposeImage((GpImage*)gpBitmap);
 				if (!hBitmap.IsNull) PInvoke.DeleteObject(hBitmap);
 				return HRESULT.E_FAIL;
 			}
 
+			// Allocate buffer for flipped pixel data
+			IntPtr flippedBits = Marshal.AllocHGlobal(bmp.bmWidthBytes * bmp.bmHeight);
+			byte* src = (byte*)bmp.bmBits;
+			byte* dst = (byte*)flippedBits;
+
+			// Flip the image manually row by row
+			for (int y = 0; y < bmp.bmHeight; y++)
+			{
+				Buffer.MemoryCopy(
+					src + y * bmp.bmWidthBytes,
+					dst + (bmp.bmHeight - y - 1) * bmp.bmWidthBytes,
+					bmp.bmWidthBytes,
+					bmp.bmWidthBytes
+				);
+			}
+
+			// Create GpBitmap from the flipped pixel data
+			IntPtr gpBitmapPtr;
+			if (GdipCreateBitmapFromScan0(bmp.bmWidth, bmp.bmHeight, bmp.bmWidthBytes, PixelFormat32bppARGB, flippedBits, out gpBitmapPtr) != 0)
+			{
+				Marshal.FreeHGlobal(flippedBits);
+				if (!hBitmap.IsNull) PInvoke.DeleteObject(hBitmap);
+				return HRESULT.E_FAIL;
+			}
+
+			Marshal.FreeHGlobal(flippedBits);
+
+			GpBitmap* gpBitmap = (GpBitmap*)gpBitmapPtr;
+
 			if (TryConvertGpBitmapToByteArray(gpBitmap, out thumbnailData))
 			{
 				if (!hBitmap.IsNull) PInvoke.DeleteObject(hBitmap);