shared database is overwritten (not merged) when configured with challenge-response with yubikey

[krikk]

Overview

user1 and user2 open a shared keepass file (on a UNC Path), which is protected with password + challenge-response (yubikey)

Steps to Reproduce

1. user1 opens file with yubikey plugged
2. user2 opens file with yubikey plugged
3. user2 leaves keepassxc open but unplugs the yubikey (he goes on lunch break, keeps workstation and keepassxc running)
4. user1 adds an entry to the shared keepass file
5. the keepassxc process on user2 workstation tries to reload the keepass file, but fails to do so, because yubikey is missing
6. user2 returns from break and re-plugs yubikey (but does not change anything)
7. user2 closes keepass database (user gets NO warning prompt or anything) -> file seems to be saved automatically on close

-> BOOM user2 overwrites the change of user1, the entry from user1 is lost!

Expected Behavior

keepassxc should check for changes on the filesystem on every save?

Actual Behavior

user2 overwrites the change of user1, the entry from user1 is lost!

Context

if the user2 in step6 does not replug the key, he will get a warning about saving changes on closing keepassxc

screen after step 5:

screen the user2 sees before closing keepassxc (before step 7):

KeePassXC - Version 2.7.4
Revision: 63b2394

Qt 5.15.6
Diagnosemodus ist deaktiviert.

Betriebssystem: Windows 10 Version 2009
CPU-Architektur: x86_64
Kernel: winnt 10.0.19045

Aktivierte Erweiterungen:

• Auto-Type
• Browser-Integration
• SSH-Agent
• KeeShare
• YubiKey
• Schnelle Entsperrung

Kryptographische Bibliotheken:

• Botan 2.19.1

my keepassxc.ini:

[General]
ConfigVersion=2
UpdateCheckMessageShown=true
AutoTypeHideExpiredEntry=true
OpenPreviousDatabasesOnStartup=false
AutoSaveAfterEveryChange=true
BackupBeforeSave=false
UseAtomicSaves=false
FaviconDownloadTimeout=3
GlobalAutoTypeKey=65
GlobalAutoTypeModifiers=201326592
BackupFilePathPattern={DB_FILENAME}-{TIME:yyyy-MM-dd_HH-mm-ss}.kdbx

[GUI]
CheckForUpdates=false
TrayIconAppearance=monochrome
ShowExpiredEntriesOnDatabaseUnlock=false
HidePasswords=true
AdvancedSettings=true
HidePreviewPanel=true
CompactMode=false
ApplicationTheme=classic

[Security]
LockDatabaseScreenLock=false
EnableCopyOnDoubleClick=true
AutotypeAsk=false
ClearClipboardTimeout=15
PasswordsRepeatVisible=false
IconDownloadFallback=true
ClearSearch=false

[Browser]
CustomProxyLocation=
Enabled=true
BestMatchOnly=false
SearchInAllDatabases=true
AlwaysAllowAccess=true

[SSHAgent]
UsePageant=true
UseOpenSSH=false
Enabled=true

[droidmonkey]

Always lock your database when you unplug your yubikey.... until #5290 is fixed