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.
With RAILWAYS, highway-like sectors double as rail. They need to be
at least 5% efficient to be operational, and then they additionally
extend rail into adjacent sectors that are at least 60% efficient.
New opt_RAILWAYS, SCT_HAS_RAIL(), sct_rail_track(). Update
sector_mcost(), bp_neighbors(), lnd_mar_one_sector() for RAILWAYS
mobility rules. Update sinfra(), spyline(), satdisp_sect() to show
rail track instead of rail infrastructure for RAILWAYS.
New virtual sector selector track, implemented by nsc_sct_track().
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.
move costs, but failed to make A* use these costs. This broke land
unit path finding. Fix:
(MOB_ROAD, MOB_MOVE, MOB_MARCH): Split MOB_ROAD into MOB_MOVE and
MOB_MARCH. Users changed.
(lnd_mobcost, sector_mcost): Move minimum mobcost logic to
sector_mcost(), where it is visible to A*. Also fixes unit reaction
path cost.
(lnd_path): Fix confusing message: don't claim there's no path when
all we really know is that there's no railway.
regardless of the option, but forced to sct_effic when disabled. This
screws up sct_defense when you disable DEFENSE_INFRA. Implement it
more like FALLOUT: use sct_defense if enabled, else sct_effic. The
change should be invisible except in xdump, which shows the real
sct_defense. Closes#804641.
(SCT_DEFENSE): New.
(dump, sinfra, sector_strength): Use it.
(eff_bomb, build_bridge, build_tower, new, buildeff, sect_damage)
(put_combat, checksect, produce_sect): Don't force sct_defense to
sct_effic when DEFENSE_INFRA is disabled.
thread entrypoints:
(lwpSelect, shutdown_sequence): Parameters didn't match thread entry
point prototype.
(lwpEntryPoint): Arguments didn't match thread entry point prototype.
Change linkage of functions without prototype declaration to static
where possible.
Remove some superflous declarations, replace others by suitable
includes.