gdiplus: Set correct color space flags for grayscale images.

dlls/gdiplus/image.c

@@ -3718,7 +3718,14 @@ static GpStatus decode_frame_wic(IWICBitmapDecoder *decoder, BOOL force_conversi
     if (status == Ok)
     {
         /* Native GDI+ used to be smarter, but since Win7 it just sets these flags. */
-        bitmap->image.flags |= ImageFlagsReadOnly|ImageFlagsHasRealPixelSize|ImageFlagsHasRealDPI|ImageFlagsColorSpaceRGB;
+        bitmap->image.flags |= ImageFlagsReadOnly|ImageFlagsHasRealPixelSize|ImageFlagsHasRealDPI;
+        if (IsEqualGUID(&wic_format, &GUID_WICPixelFormat2bppGray) ||
+            IsEqualGUID(&wic_format, &GUID_WICPixelFormat4bppGray) ||
+            IsEqualGUID(&wic_format, &GUID_WICPixelFormat8bppGray) ||
+            IsEqualGUID(&wic_format, &GUID_WICPixelFormat16bppGray))
+            bitmap->image.flags |= ImageFlagsColorSpaceGRAY;
+        else
+            bitmap->image.flags |= ImageFlagsColorSpaceRGB;
         bitmap->image.frame_count = frame_count;
         bitmap->image.current_frame = active_frame;
         bitmap->image.decoder = decoder;

dlls/gdiplus/tests/image.c

@@ -5022,7 +5022,6 @@ static void test_png_color_formats(void)
 
         status = GdipGetImageFlags(image, &flags);
         expect(Ok, status);
-todo_wine_if(td[i].bit_depth > 1 && td[i].color_type == 0)
         ok((flags & td[i].flags) == td[i].flags ||
            broken(td[i].bit_depth == 1 && td[i].color_type == 0 && (flags & ImageFlagsColorSpaceGRAY)), /* XP */
            "%d: expected %#x, got %#x\n", i, td[i].flags, flags);