text input overflow graphically input field

When configuring my wifi connection, I was asked to enter my passphrase in a dialog input field (full screen dialog).

I pasted (with middle click mouse) my 63 characters passphrase and it overflows the input field in the idalog

Best to see it in the screenshot.

I reported this upstream at https://gitlab.gnome.org/GNOME/gnome-shell/issues/259

But as I have checked that I can't reproduce this in archlinux, I was said it is certainly an ubuntu bug.

This happens also in Alt-f2 dialog for example when you type a long text. See gitlab comments.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: gnome-shell 3.28.1-0ubuntu2
ProcVersionSignature: Ubuntu 4.15.0-20.21-generic 4.15.17
Uname: Linux 4.15.0-20-generic x86_64
NonfreeKernelModules: wl
ApportVersion: 2.20.9-0ubuntu7
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Thu May 10 14:04:27 2018
DisplayManager: gdm3
InstallationDate: Installed on 2018-05-07 (2 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: No upgrade log present (probably fresh install)