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.
RET_SYS was used for commands failing due to internal or environmental
errors, but not really systematically. The difference to RET_FAIL is
how dispatch() treats them: RET_SYS got logged, and cost no BTUs.
More specific logging is possible at the point of failure than in
dispatch(). Make sure that's done for all failures that used to
return RET_SYS.
The change in BTU charging affects commands consider, offer, repay,
trade failing due to internal errors. It also affects deity commands
reload and turn (irrelevant because deities get unlimited BTUs), and
commands apropos, info and motd (irrelevant because they cost no
BTUs).
Only treaty extension initialized ef_type and uid properly. None of
them zeroed unused members and holes in the struct. comm and trade
extension called ef_extend(), which had no effect, so remove that.
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.
(ltend, multifire, quite_bigdef, mine, landmine)
(do_loan, prod, printdiff, sell, sona, stre)
(tend, fire_dchrg, vers, work, ac_planedamage)
(ac_shipflak, ask_off, get_mine_dsupport, att_fight)
(ask_move_in_off, detonate, sd, land_gun)
(land_unitgun, lnd_fort_interdiction, lnd_fortify)
(perform_mission, pln_mine, pln_mobcost)
(retreat_ship1, retreat_land1, shp_sweep)
(shp_fort_interdiction, shp_missle_defense)
(new_work, growfood, upd_land, land_repair)
(get_materials, do_mob_ship, do_mob_land)
(load_it, unload_it, prod_plane, produce)
(guerrilla, upd_buildeff, spread_fallout)
(upd_ship, ship_repair, min, dmin, MIN):
Remove min() and dmin() functions and replace
with a MIN macro in misc.h. Remove local MIN
macros and use the new one in misc.h. This
change removes the need for the special
case for _WIN32.
(fuel, look_ship, multifire, mission, sona)
(plane_sona, ef_open, player_accept, player_main)
(ac_dog, att_get_combat, calc_mobcost)
(ask_move_in_off, intelligence_report)
(build_mission_list_type, perform_mission)
(show_mission, use_supply, dodistribute)
(allocate_memory, max, dmax, MAX):
Remove max() and dmax() functions and replace
with a MAX macro in misc.h. Remove local MAX
macros and use the new one in misc.h. This
change removes the need for the special
case for _WIN32.
