Feature/430 fix unclean shutdown

[phoerious]

Description

This is a partial fix for issue #430. It resolves shutdown problems on OS X when using the "Quit" action from the right-click menu on the dock.

It also contains an incomplete clean shutdown implementation for Windows. The signaling mechanism via CreateEvent() and SetEvent() works in general, but trapping the actual system events doesn't. The control handler registered by SetConsoleCtrlHandler() isn't called. Maybe someone more knowledgeable in Windows API internals can help me here. I suppose it may be that Windows doesn't treat KeePassXC as a console application or some other stupid reason.

EDIT: Windows implementation canceled, considered a non-issue (mostly).

How has this been tested?

Ran on macOS Sierra and Windows 10.

Types of changes

• ✅ Bug fix (non-breaking change which fixes an issue)

Checklist:

• ✅ I have read the CONTRIBUTING document. [REQUIRED]
• ✅ My code follows the code style of this project. [REQUIRED]
• ✅ All new and existing tests passed. [REQUIRED]
• ✅ I have compiled and verified my code with -DWITH_ASAN=ON. [REQUIRED]

[TheZ3ro]

@phoerious Is this a WIP on Windows side or it's ready to merge?

[phoerious]

I don't know. If someone has any ideas why it's not working, I'd appreciate any hints.

[phoerious]

I did some more research, but couldn't find anything else that would help me.

In addition to what I already submitted, I also tried to make it work using signal() from signal.h, but without success. It appears that Ctrl+C just cannot be trapped from an Msys terminal. Neither approach allowed me to trap interrupt signals/events.

Since the task manager seems to send a clean close signal to the window anyway and not an interrupt signal when clicking "End Task", I decided to undo my last commit on this patch and only submit the macOS code. The behavior upon Windows shutdown should be about the same as the behavior of the task manager.

I consider #430 fixed with this. It works well on Linux and macOS and on Windows it cannot really be fixed, but also doesn't appear to be much of an issue in the first place.

[TheZ3ro]

Is this related keepassx/keepassx#169 ?

[phoerious]

No, that's a different problem.

[TheZ3ro]

Ok so I will test and review this 😉

PS: Can you first review and merge #545 and then rebase this?

[phoerious]

I tested it already and only marked a few code style problems. Once those are fixed, it can be merged.

[TheZ3ro]

Looks good

[Keisial]

signal(SIGINT, ...) should work fine on Windows (at least it used to). Are you building it as a console or Windows application? In the later case, it would not have a console attached (but I don't see how you could be sending Ctrl-C from msys either).

[phoerious]

I don't think I build it as a console app. When I start it from the Windows command line, it immediately detaches from the console, but when I start it from Msys2, it stays connected to the shell, so that I can exit it with Ctrl+C. When I print stuff to. STDOUT, I also see it in the terminal, but Ctrl+C just quits immediately as if it sent a SIGKILL.

[Keisial]

msys may be doing something odd here in order to "reattach" the program. I would try rebuilding with the -mwindows flag removed from the linking step.
Also, what's the behavior when you kill -SIGINT from a different console?