[Feature request?] Make abroot not lock ifself if the current upgrade is cancelled by user

[fluoriteByte]

i think abroot should be able to unlock itself if the user cancelled an upgrade or if the upgrade pre-staging fails (during update check or during download)
it gets kinda annoying trying to test abroot when it keeps locking up needing a reboot

[taukakao]

Yeah, it should be possible to abort until the "safe point".
Though currently it's not defined correctly. It's here:

ABRoot/core/system.go

Lines 700 to 705 in 1c3f672

	// from this point on, it is not possible to stop the upgrade
	// so we remove the stage file. Note that interrupting the upgrade
	// from this point on will not leave the system in an inconsistent
	// state, but it could leave the future partition in a dirty state
	// preventing it from booting.
	err = s.RemoveStageFile()

This information is wrong, Generating the Fstab, crypttab and systemd mount units will not leave the system in an inconsistant state. It only affects the .system.new folder, which is completely independant.

The actual "safe point" would be before these lines probably:

ABRoot/core/system.go

Lines 815 to 818 in 1c3f672

	err = CopyFile(
	filepath.Join(systemNew, "boot", "vmlinuz-"+kernelVersion),
	filepath.Join(initMountpoint, partFuture.Label, "vmlinuz-"+kernelVersion),
	)

I think this is the first time something from the old future system is overwritten, but this needs to be evaluated further.

[taukakao]

One additional thing: We would probably need to capture "os.Interrupt" so that we can clean up the lockfile even if the user interrupts with Ctrl+C.