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.
(BP_CIVIL, BP_SHELL, BP_GUN): These were used write-only. Remove.
(bud_key): Update accordingly.
(bp_item_idx): enumeration type for the bp_item[] indexes. Use where
appropriate.
(bp_get_item): Oops on access to an item that is not tracked.
changed. Switch from int to short, to match struct sctstr members
sct_item and sct_avail.
Symbolic indexes for struct bp member bp_item[]:
(BP_NONE, BP_CIVIL, BP_MILIT, BP_SHELL, BP_GUN, BP_LCM, BP_HCM)
(BP_MAX): New.
(bug_key): Use them. Values are now array indexes, not indexes + 1.
(bp_get_item, bp_put_item, bp_set_from_sect): Update for changed
bud_key[].
type. Make it abstract because that's possible. Change data layout
so that the slots belonging to a sector are together in memory, it's
nicer to the cache.
(bp): The new type. Users changed.
(get_wp): Update accordingly.
(alloc_bp): New.
(update_main, calc_all): Use it. Before, calc_all() allocated 1/7
more than necessary.
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.
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.
I_BAR, I_FOOD, I_OIL, I_LCM, I_HCM, I_UW, I_RAD, I_MAX): Turn macros
into enumeration constants.
(i_type): New. Use where appropriate. No functional changes, except
that I_NONE is now catched properly in a few places.
