Why upgrade? I'm not a lawyer, but here's my take on the differences
to version 2:
* Software patents: better protection against abuse of patents to
prevent users from exercising the rights under the GPL. I doubt
we'll get hit with a patent suit, but it's a good move just on
general principles.
* License compatibility: compatible with more free licenses, i.e. can
"steal" more free software for use in Empire. I don't expect to steal
much, but it's nice to have the option.
* Definition of "source code": modernization of some details for today's
networked world, to make it easier to distribute the software. Not
really relevant to us now, as we normally distribute full source code.
* Tivoization: this is about putting GPL-licensed software in hardware,
then make the hardware refuse to run modified software. "Neat" trick
to effectively deny its users their rights under the GPL. Abuse was
"pioneered" by TiVo (popular digital video recorders). GPLv3 forbids
it. Unlikely to become a problem for us.
* Internationalization: more careful wording, to harden the license
outside the US. The lawyers tell us it better be done that way.
* License violations: friendlier way to deal with license violations.
This has come out of past experience enforcing the GPL.
* Additional permissions: Probably not relevant to us.
Also include myself in the list of principal authors.
(schedulefil): New.
(set_dirs, set_paths): Rename. Initialize schedulfil.
(read_schedule): New. Can read several updates, which will be used in
later changesets.
(update_time): Change to array. Will be used in later changesets.
(update_schedule_anchor): New.
(update_init): Initialize it.
(update_get_schedule): New.
(update_init): Call it to initialize update_time[].
(update_sched): Rewrite.
(update_forced, update_wanted): Replace.
(update_reschedule): New.
(main): Call it on SIGHUP to reload the schedule.
(update_trigger, update_force, force, player_coms): Drop force's
capability to schedule updates in the future, because it's not worth
the trouble to implement again. Deities can simply edit the schedule
file to schedule updates. Remove update_force() and
update_trigger()'s parameter.
(upda): Update for new scheduler. Take care to keep output the same
as far as possible, even though it's ugly, to avoid breaking clients.
(update_policy, adj_update, update_times, hourslop, blitz_time):
econfig keys removed.
(update_demand, UPD_DEMAND_NONE, UPD_DEMAND_SCHED, UPD_DEMAND_ASYNC)
(update_demandpolicy, UDP_NORMAL, UDP_TIMES, UDP_NORMAL, UDP_BLITZ)
(UDP_MAX, UDP_DEFAULT, UDDEM_TMCHECK, UDDEM_COMSET, UDDEM_DISABLE)
(UDDEM_MAX, UDDEM_DEFAULT): econfig key and values replaced. Users
changed. wantupd.h is now empty, remove.
(demand_check): External linkage.
(update_policy_check): Now pointless, remove.
(is_daytime_near, min_to_next_daytime, regular_update_time)
(scheduled_update_time, next_scheduled_time, updatetime)
(next_update_time, next_update_check_time): Unused, Remove.
(demand_check, demandupdatecheck): Move call of demand_update_time()
from demand_check(), which controls all demand updates, to
demandupdatecheck(), which controls only unscheduled ones. Fixes
update command not to lie about the next scheduled demand update.
(demandupdatecheck): Check updates_disabled() so that zdone no longer
claims to trigger an update when it can't.
(update_trigger): New.
(force, zdon): Use it.
(update_sem, update_force): Internal linkage.
(update_trigger, update_force): Passing a pointer to static storage as
thread argument is racy. Use dynamic allocation.
other. Ensure headers in include/ can be included in any order
(except for econfig-spec.h, which is special). New header types.h to
help avoid inclusion cycles. Sort include directives. Remove some
superflous includes.
