xfce4-panel locks itself if a contextual menu is open while the application is closing

[GridCube]

closing an application from the contextual menu and then opening the contextual menu while the application is closing makes it so the panel gets locked if the application is no longer listed.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: xfce4-panel 4.12.2-1ubuntu1
ProcVersionSignature: Ubuntu 4.15.0-23.25-generic 4.15.18
Uname: Linux 4.15.0-23-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.2
Architecture: amd64
CurrentDesktop: XFCE
Date: Sun Jun 24 00:25:55 2018
InstallationDate: Installed on 2016-02-13 (861 days ago)
InstallationMedia: Xubuntu 15.10 "Wily Werewolf" - Release amd64 (20151021)
SourcePackage: xfce4-panel
UpgradeStatus: Upgraded to bionic on 2018-04-06 (78 days ago)

[CDGSThermi (e-noel)]

As the tile says, the panel locks up when the context menu (right click menu on an application's panel object in the task bar) is open while any application with an object in the task bar terminates.

After it locks up, one can not interact with the panel or anything in it anymore. It changes when a tab is closed and one can change tabs using alt+tab though. Using alt+f4 to close all tabs and then hitting it once again brings up a menu that enables users to log off, reboot, restart, suspend and other things.

After the user logs off and logs back in, the panel works again.

This is reproducible.

[CDGSThermi (e-noel)]

It's still a thing in panel version 4.12.2.

[CDGSThermi (e-noel)]

Still a thing in version 4.12.4

[Theo Linkspfeifer (lastonestanding)]

According to https://bugzilla.xfce.org/show_bug.cgi?id=13600, this bug is fixed in version 4.13.

[Andreldm-2 (andreldm-2)]

This is very likely fixed in 4.13, as reported in Bug 13600.
Can you check this version?

[CDGSThermi (e-noel)]

Fixed in 4.13.0. Thank you for your time and efforts.

[Sean Davis (bluesabre)]

Reportedly fixed upstream.