Characters from dead keys shown in plan view in password field on login screen

[Per Larsson]

1) lsb_release -rd
Description: Ubuntu 20.10
Release: 20.10

2) apt-cache policy gdm3
gdm3:
  Installed: 3.38.1-2ubuntu1.1
  Candidate: 3.38.1-2ubuntu1.1
  Version table:
 *** 3.38.1-2ubuntu1.1 500
        500 http://se.archive.ubuntu.com/ubuntu groovy-updates/main amd64 Packages
        100 /var/lib/dpkg/status
     3.38.1-2ubuntu1 500
        500 http://se.archive.ubuntu.com/ubuntu groovy/main amd64 Packages

3) I expect all characters, even those from dead keys, to be hidden the same ways as other characters

4) When using dead keys to add accents to letters on the password prompt on the login screen, before the letter the dead key is intended for is typed, the special characters from the dead keys are displayed in plain sight, instead of being obscured by dots as other letters and characters are.

Screenshot attached.

ProblemType: Bug
DistroRelease: Ubuntu 20.10
Package: gdm3 3.38.1-2ubuntu1.1
ProcVersionSignature: Ubuntu 5.8.0-34.37-generic 5.8.18
Uname: Linux 5.8.0-34-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.11-0ubuntu50.3
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: ubuntu:GNOME
Date: Tue Jan 5 12:51:19 2021
InstallationDate: Installed on 2018-11-26 (770 days ago)
InstallationMedia: Ubuntu 18.10 "Cosmic Cuttlefish" - Release amd64 (20181017.3)
SourcePackage: gdm3
UpgradeStatus: Upgraded to groovy on 2020-11-01 (64 days ago)

[Per Larsson (albatorsk)]

I don't believe this is a duplicate of https://bugs.launchpad.net/bugs/1772791 as this is specifically about using dead keys when typing in a password. At no time does the entire password display in clear text. Only the accents of dead keys are shown, but as the intended letter is then pressed, the completed letter with accent is hidden.

[Per Larsson (albatorsk)]

If this bug was a duplicate of or related to https://bugs.launchpad.net/bugs/1772791 I would expect the whole password to be visible. Please see newly uploaded screenshot. Only the accent from the dead key is visible, while the other three letters in the password are obscured.

[Marc Deslauriers (mdeslaur)]

I can reproduce this on Ubuntu 20.04 and Ubuntu 20.10

[Daniel van Vugt (vanvugt)]

The closest upstream bug I can find is https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/933

If you think a new bug is required instead of that then please create one and tell us the ID here.