>> 	After doing cc -E, I now believe "long" is mistakingly used for file
>> 	offset, instead of off_t, like return value and argument for gzseek().
>> 	I'd like to propose the following fix.
>A better fix would be to find out why HAVE_UNISTD_H is not defined and

	Because HAVE_UNISTD_H is not in src/lib/libz/Makefile.
	I think original libz was using configure (GNU autoconf).
	Is it correct?

>make sure it is defined in the future.  All NetBSD systems have unistd.h
>and should use it.

	I think it is better not defining it in zconf.h, as the symbol
	will become visible to third-party user code and may affect their
	compilation (though I believe it is rare to get bad sideeffect,
	I prefer not defining it for safety).

itojun