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.
The old code used getstarg() to get an argument with a different
prompt than snxtitem() uses, then passed the value to snxtitem()
unchecked. If the player aborts, getstarg() returns a null pointer,
and snxtitem() prompts again. Affected:
* load/lload plane/land third argument; load_plane_ship(),
load_land_ship(), load_plane_land(), load_land_land()
* bomb, drop, fly, paradrop, recon and sweep second argument;
get_planes()
* tend and ltend second and fourth argument; ltend(), tend(),
tend_land()
* mission second argument; mission()
Fix by making snxtitem() taking a prompt argument, null pointer
requests the old prompt.
Use that to simplify multifire() and torp(). Change the other callers
to pass NULL.
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.
(feed_ship, feed_land): Use it.
(do_feed): Use it. Estimate of food needed was one too large for
integer food needs. Used to round fractional food need to nearest
instead of up for supply_commod(), which could cause starvation.
(s_commod, get_minimum): Use it. Estimate of food needed was one too
large for integer food needs. s_commod() used to reserve one more
than get_minimum() would have returned; it's now the same.
(famine_victims): New.
(feed_people): Use it. This rounds victim fractions down instead of
up. It also dosn't flush needs <=1 to zero. Doesn't change
starvation, as do_feed() always produces at least one emergency food.
Does change food consumption.
(starve_some): New.
(feed_people): Use it.
(feed_ship): Use feed_people(). This rounds victim fractions down
instead of up.
(feed_land): Use feed_people(). Rounding of victim fractions
unchanged. Feeds all people not just mil; closes#913997.
(starv_people): New.
(starv_sects, starv_ships, starv_units): Use it. Fixes starve land to
talk about people instead of mil.
(starv_sects): Use famine_victims() rather than feed_people(). Take
emergency food into account, because feed_people() doesn't. Don't aim
for one extra food, for consistency with starv_ships() and
starv_units().
(feed_people): Remove useless parameter. Simplify.
(starv_ships, starv_ships): Use famine_victims() rather than
feed_ship() and feed_land().
(feed_ship, feed_land): Remove useless parameters. Internal linkage.
Simplify.
(feed_land): Call resupply_commod() only if there's a food shortage.
Don't scrounge lnd_ship for food, resupply_commod() already does.
arrays instead of copies made by getvec(). This is safe, because the
old code made single copies and always flushed them back into the unit
structures. Else make copies by hand, not with getvec.
(starv_sects): Replace getvec() by direct, read-only item access.
(upd_buildeff, enlist, materials_charge, materials_cost, produce,
grow_people, growfood, trunc_people, do_feed, feed_people): Change
argument type to match uncopied item arrays.
(growfood): Obey ITEM_MAX.
of copies made by getvec(). This is safe, because the new code
changes the item array precisely when the old code writes back a
changed copy.
(starv_ships, starv_units): Replace getvec() by direct, read-only item
access.
(feed_ship, feed_land): Remove parameter vec, work with sp->shp_item[]
and lp->lnd_item[] instead.
(plague_people): Change argument type to match uncopied item arrays.