grickit/GambCiv — comment on commit 839d1a4f1a7ae5b935c83398bf71f134ceac84a3
File: utils/commands/buildings/shipyard.cfg line 286
By AI0867:

This together with the $($i+1) part means that you'll skip option indexes if a ship with empty spots follows a full one.
It may work (haven't checked), but it's not very nice to wesnoth.