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 macros defining unit stat development in tech are somewhat
inconvenient to use. Define more convenient functions, and hide away
the macros near the function definitions.
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.
files ship.config, plane.config, land.config, nuke.config.
(empfile): Declare the new config files.
(install, installdirs): Install them.
(builtins): New make variable.
Add M_CANAL flag to indicate which ships can navigate a canal
in a big city. Remove the hard code values for canal from
shp_nav_one_sector() for which ships can navigate a canal.
Set M_CANAL flag in ship_chr_flags[] to match the hard
coding in shp_nav_one_sector().
Update Ship-types.t with new canal flag.
Update Sector-types.t to indicate that cities have canals.
Useless, remove. Users changed to check mchr's sentinel, because
that's clearer than comparing the index to N_MAXSHIPS or sizeof(mchr)
/ sizeof(*mchr).
(mchr): Change sentinel's m_name to NULL.
be skipped or stored in arrays of size I_MAX. I_NONE's int equivalent
becomes -1 by this patch, so all array indices of type i_type have been
checked not to use I_NONE as index. This change reduces the size of the
arrays stored in files.
capacities to straight arrays. Users now subscript the array instead
of calling vl_find() or walking the variable data structure.
(mchr, lchr): Initializers adapted.
(vl_find): No longer used. Remove file.