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.
ef_elt_by_name(), xdprval_sym() and symval() checked whether a file
type T is a symbol table by comparing ef_cadef(T) to symbol_ca, even
though T may be EF_BAD. Before commit 50cfdcb5, ef_cadef(EF_BAD)
accessed empfile[] out of bounds, which could conceivably crash or
somehow happen to yield symbol_ca. Since then, it oopses and returns
null.
Fix by testing the file type before calling ef_cadef().
Xundump had special hackery to maintain configuration tables'
sentinels: xubody() and getobj() added a sentinel element when
initializing or growing a table, which xubody() stripped off again
before returning. The latter was an unclean hack.
Replace this by building knowledge of sentinels into struct empfile:
new flag EFF_SENTINEL, set for the appropriate members of empfile[],
obeyed by ef_extend() and ef_truncate().
Commit da8a1dae (v4.3.12) introduced virtual selectors, but neglected
to update xundump. Xundump can't work for them, because they don't
provide a setter method.
This didn't actually break anything, because all virtual selectors
have flag NSC_EXTRA set, or are in table EF_VERSION, which xundump
refuses to touch.
Make deffld() oops on virtual selector, just to be safe.
Make deffld() reject fields whose selector has flag NSC_EXTRA set.
Since xundump() doesn't provides space for these, the bug could lead
to buffer overruns.
Use ef_ensure_space() in getobj(). This also makes sure objects are
properly initialized before undumping writes to them.
Clean up how sentinels are appended: instead of keeping its slot
reserved while undumping, keep it in the table, and strip it off when
done.
(caseen): Remove.
(xufldhdr, deffld): Record only fields in this part in caflds[]. This
fixes the check for duplicate fields in parts other than the first.
(cafldspp): New, to record fields in previous parts.
(xundump): Initialize and finalize it.
(xufooter): Update it. Requires new parameter ca. Caller changed.
(fldval_must_match): Use it to do the right thing for split arrays.
(chkflds): Adapt for changed caflds[].
(chkflds): The check for missing fields was skipped for all parts of a
split table instead of for all but the final part.
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.
extending any table, empty or not:
(cur_obj_is_blank): New.
(fldval_must_match): Use it instead of initialized[].
(getobj): Set it along with cur_obj.
(setstr): Move fldval_must_match() down, so that cur_obj_is_blank is
defined.
(initialized): Remove.
(xunsymbol1): Use ef_elt_byname().
(setsym): Accept any table reference, not just to symbol table.
(symval): New.
(setsym, add2symset): Use it.
(mtsymset): Last remaining user of getsymtab(); inline and simplify.
(getsymtab): Remove.
(xunsymbol1, xunsymbol): Rename.
(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.
