Wallpaper portal create file without extension

[calo001]

I noticed that when I use the Wallpaper portal it creates a copy of the file indicated from the parameters of their functions SetWallpaperUri and SetWallpaperFile, but the created file only takes the names 'background', 'both' or 'lock screen'. The file has no extension and it is located at /home/username/.config.

I found that this cause issues when I use an XML file to set a slideshow wallpaper because the background needs the .XML extension to set correctly the wallpaper, but without the extension only shows the primary color indicated at the /org/gnome/desktop/background/ GSetting.