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.
Change struct range from exclusive to inclusive upper bounds, for
consistency with struct realmstr and the area syntax. Also fix many
bugs.
real()'s conversion from struct range's exclusive upper bounds to
struct realmstr's inclusive upper bounds could underflow and store -1
in the realms file. Harmless, because its users didn't mind:
list_realm() and nstr_exec_val() convert back to relative coordinates,
and sarg_getrange() is only used by sarg_area(), which happened to
undo the damage. The change to inclusive upper bounds gets rid of the
broken conversion.
xyinrange() incorrectly treated the upper bound as inclusive, unless
the bounds were equal. Impact:
* nxtitem() and nxtitemp() cases NS_AREA and NS_DIST attempted to hack
around xyinrange()'s lossage(!), but screwed up: sectors on the
lower bound of of a range spanning the the whole world were skipped.
This affected all command arguments that support area or distance
syntax for items. In sufficiently small worlds, it could also make
radar miss satellites and ships, sonar miss ships, satellite miss
ships and land units, nuclear detonations miss ships, planes, land
units and nukes, automatic supply miss ship and land unit supply
sources, ships and land units fail to return fire, ships fail to
fire support.
* draw_map() could draw units sitting just right or just below of the
mapped area. No effect, as these parts of the map weren't actually
shown.
xydist_range() produced an inclusive upper bound when it decided that
the range covers everything in that dimension (which it didn't get
quite right either). This could make snxtsct_dist() and
snxtitem_dist() initialize the iterator with an incorrect upper bound.
Similar impact as the xyinrange() / nxtitem() lossage.
border() could print the hundreds line unnecessarily.
snxtsct() and snxtsct_all() screwed up for odd WORLD_Y: they failed to
include (WORLD_Y - 1) / 2 in the y-range. This affected all command
arguments that support "*" syntax for sectors, plus add ... c, power
n, and break.
snxtsct_all() failed to normalize the bounds (presumed harmless).
There were a few correct, but somewhat unclean uses of struct range
with inclusive upper bounds:
* nat_reset() used one internally.
* pathrange() worked with inclusive upper bounds internally, but
corrected to exclusive upper bounds before passing the range out.
* sarg_getrange() worked with inclusive upper bounds. Its only caller
sarg_area() corrected that to exclusive upper bounds.
The change to inclusive upper bounds cleans this up.
unit_map() and xysize_range() had no issues (isn't that amazing?), but
need to be updated for the changed struct range semantics.
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.
