Panel not reserving space on borders with multiple monitors

[Alistair Buxton]

The option "Don't reserve space on borders" is not selected, but windows still appear behind the panel on my left-most monitor. See screenshot.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: xfce4-panel 4.12.2-1ubuntu1
ProcVersionSignature: Ubuntu 4.15.0-20.21-generic 4.15.17
Uname: Linux 4.15.0-20-generic x86_64
ApportVersion: 2.20.9-0ubuntu7
Architecture: amd64
CurrentDesktop: XFCE
Date: Wed May 9 17:12:52 2018
InstallationDate: Installed on 2018-05-07 (1 days ago)
InstallationMedia: Xubuntu 18.04 LTS "Bionic Beaver" - Release amd64 (20180426)
SourcePackage: xfce4-panel
UpgradeStatus: No upgrade log present (probably fresh install)

[Alistair Buxton (a-j-buxton)]

Here is a screenshot of my panel config.

Panel 2 is the panel which is not reserving space.

1, 3, 5 are the bottom panels, so I have hidden them.

The selected line has p=0. If I change this to p=11 to match panel 4 then space is reserved. I don't know what "p" means, and it doesn't affect anything in the panel configuration panel, which is identical for panel 2 and 4.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Teun Beijers (teuneboon)]

Although I'm not on Ubuntu this is the only issue I could find about this: I have the same issue with xfce, and it seems like it has something to do with the fact that my main screen is 2560x1440 and my second screen 1920x1080. So my suspicion as a programmer would be that it sees "1440" as the edge even on the 1080p screen, so playing a panel at the bottom of my 2nd screen is not detected as being "on the edge". My C is too rusty to confirm this suspicion myself though.

[fbernier (francois.bernier)]

Having this issue and it seems to be a problem due to a combination of "span monitors" and "don't reserve space on borders".

I have two monitors, one on top of the other, and a bottom panel with both "span monitors" and "don't reserve space on borders" UNCHECKED. With this configuration, the bottom panel is at the bottom of the top monitor.

If I maximize and application on the top monitor, it goes up to under the bottom panel. If I maximize an application on the bottom monitor, it leaves the exact space of a panel at the bottom, but there is no panel there. It's at the bottom of the top monitor.

[Eric Hidle (eric-hidle)]

I can add that in my 2x2 monitor arrangement, the panel is reserving space but on the wrong monitor. If the panel is on a monitor on the bottom row, it reserves space on the monitor directly above it instead of the monitor that it's on. Seems to be a variation of @fbernier comment.

On my variation, the panel is at the top of the bottom monitor, and panel is reserving space at the top of the monitor above it. If I put the panel on the top monitor, the behavior is what is expected.

However, if I put the panel at the bottom of any monitor, it does not reserve space anywhere.