Expected Behavior

Any open "Browser Confirm Access" dialog should be automatically denied and closed.

Current Behavior

If the Allow button is pressed after closing the database, the program crashes.

Possible Solution

1. Add some new safeguards to prevent the crash.
2. Automatically deny and close these dialogs.

Steps to Reproduce

1. Create a new entry and connect a browser to KeePassXC.
2. Go to the login page and get the "Browser Confirm Access" dialog.
3. Do not act on the dialog. Instead, focus the main window and close the database.
4. Click the Allow button.
5. The program crashes.

Context

I just happened to accidentally run across this. I think this is very rare, but it could perhaps lead to data loss if multiple databases are open.

Debug Info

KeePassXC - Version 2.4.1
Revision: 7bafe65

Qt 5.12.2
Debugging mode is disabled.

Operating system: macOS Mojave (10.14)
CPU architecture: x86_64
Kernel: darwin 18.5.0

Enabled extensions:

• Auto-Type
• Browser Integration
• SSH Agent
• KeeShare (only unsigned sharing)
• YubiKey
• TouchID

Cryptographic libraries:
libgcrypt 1.8.4