When `$oldver` is not old enough

[5long]

Consider the following situation:

• User fully upgraded the system, package systemd upgraded from 250.5-1 to 251.1-1, left a file /etc/systemd/system.conf.pacnew
  • There are 2 new lines in the config file: #RuntimeWatchdogPreSec=off and RuntimeWatchdogPreGovernor=
• User didn't run p3wm either due to lack of time, interest, or failing to notice the pacnew file notice printed by pacman.
• A few weeks later, user fully upgraded the system again. Now package systemd goes up to version 251.4-1
• Now the user decides that it's time to maintain the system and runs p3wm on all the existing .pacnew files.

What happens next:

p3wm /etc/systemd/system.conf.pacnew would pick systemd=251.1-1 as the base version (stored in variable $oldver) to three-way merge. The merge tool would thought that #RuntimeWatchdogPreSec=off should be removed.

What should've happened ideally:

p3wm should've picked 250.5-1 as the base version. The merge tool should see that #RuntimeWatchdogPreSec=off is added in the new version of package and keep it in the merged file.