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.
World-sized bitmaps were allocated with size WORLD_SZ() / 8, which
expands to (WORLD_X * WORLD_Y / 2) / 8. The divisions truncate unless
WORLD_X * WORLD_Y is a multiple of 16. The bitmaps were one byte too
small then. Bitmap overruns happen when:
* A lookout looks at one of the last sectors of the sector file.
Besides commands look and llook, this affects navigate and march
sub-command 'l'.
* Command spy spies into one of the last sectors of the sector file.
* A map or nmap (but not a bmap) shows one of the last sectors of the
sector file, or a sector that can see one of the last sectors
(visual range is two sectors at 100% efficiency). Besides commands
lmap, map, nmap, pmap, smap, this affects move and transport
sub-command 'm'.
Diagnosed with valgrind.
Already broken in BSD Empire 1.1 (bitmaps were on the stack then).
Replacing getrel(getnatp(US), THEM) by relations_with(US, THEM) makes
a difference only when US equals THEM. Replace in places where it's
obvious that they're not equal.
Note: getsect() sets player->owner to "player is god or owns this
sector". Thus, after getsect(..., §), sect.sct_own ==
player->cnum implies player->owner. Conversely, !player->owner
implies sect.sct_own != player->cnum. Similarly for getship(),
getplane() and nxtitem().
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().
spy() stored coordinates of sectors successfully spied in an array.
Since it didn't bother to normalize coordinates, it could spy sectors
near the "seams" of the world more than once. The array was also
wastefully large.
Fix by using a sector bitmap instead, like do_look().
Spies shot were only deduced from sector military; land units were
immune to losses; in fact they needn't have any military to spy.
Fix by requiring and using only sector military. Closes#758483.
Make spy() not skip sectors without civilians, military and land
units. There could be other interesting things to report there:
efficiency, gold bars, planes...
The values in these columns were computed by count_sect_units() and
count_sect_planes(), which included land units and planes in the count
that aren't shown by prunits() and prplanes(), namely own and embarked
units. Confusing. Moreover, count_sect_planes() and prunits() rolled
dice separately for spy units. This could leak the presence of spies
even when prunits() didn't show them.
All fixable, but not worth the trouble; just remove the counts.
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.
format.
(prplanes): Fix dangerous misuse of pr(): passed formatted string
instead of format string and arguments. Crash bug if formatted string
contains '%'. Players can put that in country names...
of copies made by getvec(). This is safe, because the old code made
single copies and always flushed them back into the unit structures
before flushing those.
