Failed attempts count wraps around after INT_MAX wrong login attempts

[sur5r]

(Forwarded from https://bugs.debian.org/921773)

When run with --show-failed-attempts i3lock unconditionally increments failed_attempts.

This would wrap around of course, but on most systems, PAM delays unsuccessful attemps by 3 seconds. So it would take INT_MAX*3 seconds to happen which is roughly 204 years on a 32 bit system.

I don't think it makes sense to add more logic to this counter, but I wanted to check with you first.

[stapelberg]

Yeah, I agree that this is not a security issue, given that PAM delays attempts.

It’s also easy to fix, though, and not worth discussing with the reporter, so I just sent a small code change to take care of the problem (PR #369).