"Don't not resolve space on border" does not work when you have 4 monitors

Submitted by kke..@..il.com

Link to original bug (#15220)

Description

"Don't not resolve space on border" does not work when you have 4 monitors.

For horizontal panel bar, each monitor can have 2 panel bar (upper/bottom). Etc, "------" means a panel bar.

------
  M
------

So if I add panel bars to all monitors, it looks like

------ ------
  M1   M2
------ ------
------ ------
  M4   M3
------ ------

Totally 8 panel bars. However, among these 8 bars, only 2 bars respect the setting of ""Don't not resolve space on border"". Other 6 bars always hide the application content, which is very very annoying. Here are the 2 bars location which respect the setting.

------ ------
  M1   M2


  M4   M3

Env: Xubuntu 18 LTS. xfce4.12

Version: 4.12.0