function wp_basename is wrong in windows

Hi.I find a bug.
In /wp-includes/media.php about line 441.
The code is:
$info = pathinfo($file);
$dir = $info[‘dirname’];
$ext = $info[‘extension’];
$name = wp_basename($file, “.$ext”);`

In my works the $file values :
$file = ‘D:\wwwroot\9thq-main/wp-content\uploads\slideshow-gallery5.jpg’;
But the result of $name is : ‘wp-content\uploads\slideshow-gallery5’
It is not true!

In my tests, I find that the function wp_basename() is not works very well.
The code is:
basename( str_replace( ‘%2F’, ‘/’, urlencode( $path ) )
It only tranforms ‘/’ but miss the ‘\’;
It neglects the symbol of the path in windows;