[tlbuild] build failure: libs/zziplib/zziplib-0.13.58/zzip/stat.c needs #include <strings.h> for strcasecmp

[Karl Berry]

    #if defined(_AIX)
    #include <strings.h>
    #endif
    to the end of zziplib-0.13.58/zzip/conf.h

zzip's handling of strcasecmp seems complex. There is one alternative
definition in strcasecmp in mmapped.c, and a related one in file.c
(dirsep_strcasecmp).  Maybe they have to be different to comply with zip
format rules, I don't know.  Meanwhile, _stricmp is used on Windows
(conf.h), and no global strcasecmp replacement is defined.

So I suppose adding another system-dependent define and random usage of
a system strcasecmp function would fit right in :). 

Given these other (re)definitions of strcasecmp, I would suggest making
the change in stat.c instead of conf.h, to avoid possibly unwanted
interactions with the other code.

Really cleaning this up seems like something the zzip author would be in
the best position to do.

    Because I do not quite understand how the -PATCHES approach works, I
    have not done an actual commit. Peter, can you explain how that local
    TL patch setup is to be used?

The -PATCHES are there to record the changes we make from the original,
so that we can (a) send them back upstream, and (b) review/reinstall
them when a new original is released.  The build system itself does not
do anything with the -PATCHES; we just manually enter/update them there
as changes are made.

In other words, modify zzip/stat.c (or conf.h),
make an entry in Build/source/libs/zziplib/zziplib-0.13.58-PATCHES/ChangeLog,
and add the diff in that directory (with some arbitrary number).

Thanks,
k