Shading maximised windows causes the window to move down by about 8 pixels..

Submitted by Benjamin

Assigned to Olivier Fourdan @olivier

Link to original bug (#9621)

Description

If I maximise Firefox and then scroll up on the border to shade it, it moves the entire window down by about 8 pixels and once I unshade it, it's still 8 pixels down, while still maximised.. I'm using a theme with a really small border ( http://xfce-look.org/content/show.php/Prelude_Dark?content=154040 ) and I think that's why it happens..

Screenshot: http://imgur.com/a/VZSVn#0

Version: 4.10.0