[Freeciv-Dev] Re: patch: zlib support (PR#366)

[Jeff Mallatt <jjm@xxxxxxxxxxxx>]

At 2000/07/11 10:51 , David Pfitzner wrote:
>Here is another attempt at adding zlib support, for transparent 
>compression/uncompression of savegames.  For previous discussion 
>see: http://www.freeciv.org/cgi-bin/bugs?findid=366
>(and related thread on freeciv-dev at that time).

Great!  With the extra data needed by Fog of War, I believe this patch is
very important.  (I've had some save files grow to more than 5 Meg.)

>The attached patch should address most of the issues raised last 
>time.  In particular, Jeff Mallatt wrote:
>
>> This simply doesn't compile on my machine!  My zlib.h doesn't say anything
>> about a function called gzgets(). 
>
>Should be fixed: configure now checks for gzgets in -lz.

I tested before upgrading my zlib, and ./configure correctly determined
that I didn't have the right stuff.

Then I upgraded my zlib from 1.0.4 to 1.1.3.  ./configure determined that I
did have a new enough version of zlib, so it arranged to include
compression.  When I did the 'make', the server linked but the client did
*not* link!  It turns out that the installation of XFree86 on my machine
included its own libz.a file in /usr/X11R6/lib, which was too old to
contain gzgets() and was shadowing my newly installed version 1.1.3!
Removing this libz.a allowed my client to link.

I don't know if this is worth our worrying about -- but, then again,
XFree86 is rather common. :)  A complex test might not be worth it, but
maybe just changing the referenced libraries from $LIBS to $CLIENT_LIBS in
the AC_CHECK_LIBS calls would be enough (I tested this, and it does trap
the error).

jjm