LUKS passphrase input dialog non dismissable if USB key plugged-in while screen is locked

[zebul666]

1. Lock your session with Meta+L
2. Plug in a USB key/disk with a LUKS partition
3. Log in as usual with your password
Then your desktop is overlayed with the LUKS passphrase input dialog

Bug:

- It is not dismissable, meaning clicking Cancel does nothing and dialog stays over all the desktop, and you can't do anything.
- Possibly, entering the passphrase might not work either. not tested here.
- You can only Lock again your session with Meta+L and relogin ...

Only reproduced so far on Ubuntu 18.10 and 19.04.

ProblemType: Bug
DistroRelease: Ubuntu 19.04
Package: gnome-shell 3.32.0+git20190410-1ubuntu1
ProcVersionSignature: Ubuntu 5.0.0-13.14-generic 5.0.6
Uname: Linux 5.0.0-13-generic x86_64
NonfreeKernelModules: wl
ApportVersion: 2.20.10-0ubuntu27
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Fri May 3 18:28:42 2019
DisplayManager: gdm3
InstallationDate: Installed on 2018-05-07 (360 days ago)
InstallationMedia: Ubuntu 18.04 LTS "Bionic Beaver" - Release amd64 (20180426)
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=fr_FR.UTF-8
 SHELL=/bin/bash
SourcePackage: gnome-shell
UpgradeStatus: Upgraded to disco on 2019-04-18 (14 days ago)

[Daniel van Vugt (vanvugt)]

Thank you for reporting this bug to Ubuntu.
Ubuntu 19.04 (disco) reached end-of-life on January 23, 2020.

See this document for currently supported Ubuntu releases:
https://wiki.ubuntu.com/Releases

We appreciate that this bug may be old and you might not be interested in discussing it any more. But if you are then please upgrade to the latest Ubuntu version and re-test. If you then find the bug is still present in the newer Ubuntu version, please add a comment here telling us which new version it is in and change the bug status to Confirmed.