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.
Conditions comparing strings behaved rather erratically: while wing=m
was smartly interpreted as wing='m' (because m is ambiguous as plane
selector), wing=e was not so smartly interpreted as wing=effic
(because e unambiguously identifies effic; this was then rejected due
to incompatible types), and wing=g was even less smartly interpreted
as wing=group.
Address this by a redesign of the identifier resolution rules in
nstr_comp(): If the condition contains just one identifier, it names a
selector. If it contains two, try to intepret either as selector or,
if the other can be interpreted as selector, as value for that.
String selectors accept any identifier as value, numeric selectors
only the ones listed in their table.
Interpret both identifiers as selectors only if their types are
compatible (makes rpath=gu work for ships) and their tables, if any,
match (makes type=spy work for land units).
If more than one interpretation makes sense, drop any value
interpretations of identifiers that are unabbreviated selector names,
and selector interpretations of those that are not (makes wing=w work
for planes).
Change nstr_match_val() to accept any identifier as value for a string
selector. Replace nstr_mkselval() by nstr_resolve_val(), to resolve
string values in addition to symbolic ones. Remove resolution to
string from nstr_resolve_id(), drop its last parameter. Remove unused
nstr_string_ok(). New nstr_is_name_of_ca(), nstr_ca_comparable().
Examples for conditions that are now interpreted differently:
condition old interpretation new interpretation
wing=g wing=group wing='g'
w=g wing=group rejected as ambiguous (1)
w=e wing=effic (2) wing='e'
(1) because both wing='g' and 'w'=group make sense
(2) rejected as incomparable later on
Change nstr_mkselval() to generate values with promoted types only,
and replace nstr_coerce_val() by new and simpler nstr_optype() in
nstr_comp().
Replace the only remaining use of nstr_coerce_val() in surv() by
nstr_promote(), and remove nstr_coerce_val().
This loses one half of the unimplemented sketch of coercions to
NSC_STRING. Drop the other half from nstr_exec_val().
Where ordinary selectors specify a value stored in some object,
virtual selectors specify a function to call to compute a value
associated with some object.
Use them to replace the special case xdump ver by new table
EF_VERSION.
Move configkeys[] to lib/common because nsc_init() needs it to
initialize empfile[EF_VERSION].cadef.
Move stuff to untangle the ugly cyclic dependencies between the
archives built for selected subdirectories of src/lib/:
* Move common/io.c to empthread/ because it requires empthread stuff
* Move parts of subs/nstr.c to common/nstreval.c to satisfy
common/ef_verify.o
* Move getstarg.c getstring.c onearg.c from gen/ to subs/ because they
require stuff from there
* Move bridgefall.c check.c damage.c empobj.c journal.c maps.c
sectdamage.c from common/ to subs/ because they require stuff from
there
* Move cnumb.c from subs/ to common/ to satisfy common/type.o
* Move log.c fsize.c from common/ to gen/ because they really belong
there
* Move emp_config.c mapdist.c from gen/ to common/ because they really
belong there, and require stuff from libglobal.a
Also package as/ as libas.a to satisfy common/path.o.
Remaining dependencies:
lib needs
--------------------------------------------
libas.a libglobal.a
libcommon.a libas.a libglobal.a libgen.a
libgen.a
libglobal.a
liblwp.a libgen.a
libw32.a[*] libgen.a
[*] Except for service.o, which can only be linked into the server
Link order now: liblwp.a libcommon.a libas.a libgen.a libglobal.a
libw32.a. The position of libw32.a is not quite right, but works
anyway.
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.
(ef_elt_byname): New.
(nstr_match_val): Use it to generalize to arbitrary table with
uniquely named elements. Use ca_type to find table, remove parameter
type. Callers changed.
(nstr_mkselval): Adapt sanity check accordingly.
(NSC_TYPEID): No longer needed, remove, users changed to use
appropriate integer type instead. This fixes signedness of sector
selectors des and newdes.
(meta_type): Remove entry for NSC_TYPEID.
(nstr_coerce_val): Can't detect typeid - integer mismatch anymore.
Was nice to have; perhaps revive it later.
(meta_type): Add its entry.
(setnum, nstr_promote, nstr_exec_val): Deal with it. nstr_exec_val()
implements opt_HIDDEN by mapping unknown values to -1.
(natstr, nat_ca): Use it for member nat_relate. This also halves its
size. Fixes very minor leak: before, player could see relations to
all countries, regardless of contact.
(nation_relations): Add entry for -1.
(nsc_cat) New category NSC_ID.
(nstr_comp): Resolve identifiers instead of relying on nstr_comp_val()
and nstr_coerce_val().
(valstr, nstr_coerce_val): Remove valstr member val_as_type.
(nstr_parse_val, nstr_match_ca, nstr_match_val, nstr_resolve_id)
(nstr_resolve_sel, nstr_mkselval): New.
(nstr_comp_val): Rewrite using the above.
offset and index. This is for the new dumps; conditions can't use it,
yet.
(nstr_comp_val): Zero index.
(nstr_exec_val): Implement index.
(nstr_exec_val): Simplify coercion to WANT.
type literals, unless type inference rejects the selector. This
doesn't work for NSC_TYPE selectors: `?des=n' is interpreted as
`?des=newdes'. Prefer type literal to NSC_TYPE selector. Closes
#982021.
