update-initramfs truncates initrd if MINKVER not met

[Soren Hansen]

Binary package hint: initramfs-tools

When update-initramfs runs it creates a backup of the current initrd. If one of the hooks has a MINKVER set that's not fulfilled, update-initramfs leaves an initrd of 0 bytes and the backup. If update-initramfs runs again, it overwrites the old backup with a new backup of the 0 bytes initrd. During an edgy->feisty userland upgrade, "update-initramfs -u" is run numerous times, nuking the current initrd, rendering the system unbootable.

Attaching a fix that restores the backup. I'm not sure, though, if restore_backup should be called only if minversion isn't met, or in all cases where update-initramfs fails.

[Soren Hansen (soren)]

Attaching output of "sh -x update-initramfs -u". Output of second run is identical.

[Soren Hansen (soren)]

I'm an idiot. Note to self: When running "sh -x foo" to prove a point, don't be in a directory with a fixed "foo".

[Soren Hansen (soren)]

Notice the extra "rm -f /boot/initrd.img-2.6.17-10-server.dpkg-bak"

[Soren Hansen (soren)]

Applied in Debian, and pulled in in 0.85eubuntu9.